Research Features - Issue 109

ISSN 2399-1542 ISSUE 109

Research from

France, Germany & Switzerland

– three of Europe’s research powerhouses

TOPICS COVERED:

RESEARCHERS INCLUDED:

THOUGHT LEADERSHIP

Biofluids; Biophysics; Blood; Cardiovascular; Chemistry; Computational Biology; Economics; Materials; Medical Physics; Microbiology; Psychiatry; Robotics; Statistics; Security Engineering; Ophthalmology; Ultrasound

Dr N Hamdani; Dr S Demirci; Prof Dr R Fischer; Prof Dr M Riquelme; Dr D Panayotova-Dimitrova; Prof V Wittmann; Prof F Ernst; Dr T Sabel; Dr C Fuchs; Dr A Munk; Dr K Müller-Vahl; Prof Dr S Katzenbeisser; Dr A Chapel; Dr F BeharCohen; Dr F Argoul; Dr I Alger; Dr A Salsac

Agnes Buzyn, French National Authority for Health; Dr Joann Halpern, German Center for Features Research3 Research and Innovation in New York; Dr Margret Wintermantel, DAAD; Dr Helmut Dosch, DESY

COLLABORATE DISSEMINATE ENGAGE

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WELCOME

This Issue

TO ISSUE 109

France, Germany and Switzerland have long been powerhouses of European research. This issue it has been our pleasure to meet some of the scientists conducting cuttingedge research in these countries.

Whether they are working in the field of chemistry, computing or cardiovascular medicine, these researchers are dedicated to sharing the valuable work they have undertaken.

We also speak to some of those at the head of leading European organisations. Agnes Buzyn is chairwoman of the board for the French National Authority for Health. She discusses how her personal mission to put patients at the centre of care is integral to this role.

Dr Joann Halpern, Director of the German Center for Research and Innovation in New York, has been at its helm since its very beginning. We speak to her about the centre's work fostering transatlantic collaboration and promoting German research excellence.

Dr Margret Wintermantel from DAAD describes the organisation's commitment to support scientific exchange internationally and Dr Helmut Dosch, Chairman of the Board at DESY, explains just what happens at the world’s leading centre for X-ray experiments.

The fantastic research that these researchers undertake, the broad range of expertise that they represent and the wide-ranging implications of their work illustrate the diversity and vibrancy of research in France, Germany and Switzerland.

Published by: Research Publishing International Ltd Publisher: Simon Jones Editorial Director: Emma Feloy emma@researchfeatures.com Senior Editor: Rachel Perrin rachel@researchfeatures.com Junior Editor: Hannah Fraser Editorial Assistant: Patrick Bawn Editorial Assistant: Miranda Airey Designer: Christine Burrows Head of Marketing: Alastair Cook audience@researchfeatures.com Project Managers: Annie Venables – annie@researchfeatures.com Bradley Noades bradley@researchfeatures.com John French john@researchfeatures.com Julian Barrett julian@researchfeatures.com Kate Rossiter kate@researchfeatures.com Contributors: Alex Davey Anne Freier, Barney Leeke, Christiane Wirrig, Efstratios Koutris, Ella Gilbert, Petra Kiviniemi /researchfeatures /ResearchFeature researchfeatures

Copyright © and ™ 2017

by Research Publishing International Ltd

CC BY-NC

Editor

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This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License. To view a copy of the license, visit https:// creativecommons.org/licenses/by-nc/4.0/legalcode

3

CROWDFUNDING FOR GIRLS’ & WOMEN’S EMPOWERMENT

@WomensW4

WomensWorldWideWeb

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CONTENTS

14 06 10 14 18 22

82

26 32

62 66 70

GCRI: Forging transatlantic alliances in science

The challenge of treating a stiff heart

Mycology: unravelling the riddle of the filamentous fungi

48 54

74 78

Novel mouse models reveal molecular details of skin cell death

58

82 86 90

Going with the flow

DAAD: Change by academic exchange

How to trace glycoproteins in living cells? Metabolic glycoengineering provides the answer

36 40

Robots take ultrasound to the fourth dimension A clear vision: using hydrogels to improve cataract surgery outcomes

44

Using statistical modelling to understand cell heterogeneity

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DESY: Opening new windows onto the universe

Using nanostatistics to determine the functions of cells at a molecular level

Cannabis-based medication may help to treat tics in Tourette’s Syndrome Improving cybersecurity in an increasingly technological world HAS: Giving patients a voice to improve care

Keeping an eye on visual loss through retinal oedema A fresh perspective into cancer cell development through the mechanics of cell architecture In search of the evolutionary foundations of human motivation Modelling and characterisation of microcapsules Why science needs to stop sensationalism

Stem cell therapy – the answer to radiation damage

66 5

Thought Leadership

GCRI: forging transatlantic alliances in science An ocean may divide them, but the Atlantic is proving to be no barrier to German-American collaboration, thanks to New York’s German Center for Research and Innovation. Established in 2010, the centre was founded on the principle that internationalising science and research is the key to competitiveness and sustainable economic growth. Research Features met up with GCRI director, Dr Joann Halpern to find out more.

L

ocated in the heart of New York City, the German Center for Research and Innovation (GCRI) serves as a shop window for German scientific excellence, presenting the northern European powerhouse to the American market as a land of research and innovation.

Housed in a tall, elegant building on the United Nations Plaza, it also acts as a hub where leaders in science, the humanities, and technology can come together, make connections and, ultimately, work collaboratively.

GCRI’s director, Dr Joann Halpern oversaw the creation of the centre, from the seed of an idea, to the buzzing hive of cross-cultural creativity it is today. She spoke to Research Features about the centre’s mission to foster transatlantic collaboration, and some of the exciting projects that have emerged as a result.

Could you tell us about the background and aims of the German Center for Research and Innovation?

The German Center for Research and Innovation (GCRI) New York was established as one of five German Houses of Science and Innovation worldwide. The other houses are located in Moscow, New Delhi,

São Paulo and Tokyo, and are part of the German government’s Strategy for the Internationalization of Science and Research.

Our primary goals are to present Germany to the North American market as a land of research and innovation; enhance dialogue between academia and industry; create a forum for the initiation and enhancement of transatlantic projects; and provide an information platform for the German research and innovation landscape.

One of the ways we address the aforementioned goals is to convene scientific workshops, symposia, panel discussions, and lectures that examine cutting-edge research and explore solutions to global problems that integrate different understandings of science, the economy and society. These events bring together international experts and partners from research institutions, industry and government. We also organise workshops for postdocs, graduate students and other young researchers to facilitate engagement with German institutions and support them in their careers.

What is your role within the centre?

I started working at GCRI in December 2009 and my initial role was – in collaboration with a very small and passionate team – to build

Cross-border cooperation provides not only an expanded knowledge base, but also extraordinary opportunities for scientific advancement 6

the centre from scratch. It was an exhilarating and sometimes challenging experience.

In addition to managing the GCRI team, I am responsible for strategic planning, building and expanding a global network in the science and technology space, developing new collaborations between Germany and North America in academia and industry, establishing the GCRI Foundation, our centre’s fundraising arm, preparing board meetings, making decisions about relevant topics for our events, newsletter, and online presence, and giving presentations in North America and Germany on a variety of topics, including entrepreneurship, innovation ecosystems, science diplomacy, funding opportunities and international careers.

Can you tell us about some of the interesting projects that have emerged as a result of GCRI’s work?

One of our recent projects was the creation of the GCRI Foundation/DAADRISE Scholarship for sophomores. Our foundation raised enough money to send five sophomores to conduct research in labs in Germany each summer. The individuals who receive the scholarships are students at universities in the United States or Canada who are majoring in a STEM field. The idea behind the scholarship is to get students interested in Germany and German research early in their studies. Germany has a robust, high-quality research environment, but many undergraduates are not aware of the numerous scientific opportunities Germany has to offer. A summer programme enables students to learn more about Germany and start to develop global networks in their field. We also believe that a positive summer experience will encourage them to return later in their careers. These individuals also have the opportunity to share their experiences with classmates once they return to campus. The German Academic Exchange Service (DAAD), which has decades of experience evaluating scholarship applications, has generously agreed to have its experts evaluate the GCRI FoundationRISE scholarship applications.

A more global outcome of our work is in the field of nanotechnology. A few years ago, in collaboration with our colleagues at the Center for Nanointegration Duisburg-Essen (CENIDE) and the University Alliance Ruhr, we organized an event entitled Nanovation New York: Discovering the Invisible Frontier. After an afternoon workshop with representatives from US and German universities, a US-German nanotechnology

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Image from the German Center for Research and Innovation's NanoArt exhibition. The show featured art taken directly from the labs of German research institutions.

Photo courtesy of the Center for Nanointegration Duisburg-Essen (CeNIDE)

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7

Š Beowulf Sheehan.

Thought Leadership

The German House, located on New York's United Nations Plaza.

It includes the German Center for Research and Innovation, as well as other German organizations

summer programme, a graduate student exchange programme and a professor exchange programme were initiated. That evening we organized a nanotechnology panel discussion followed by the opening of the NanoArt exhibition. Images for the exhibit were provided by a range of German institutions, including CENIDE, several Max Planck Institutes, Nanosystems Initiative Munich, the Technical University of Dortmund and a Leibniz Institute. This exhibition was so popular that it travelled to the University of California, Berkeley, MIT, the Goethe Institute in Chicago, as well as the German Houses for Research and Innovation in Tokyo and Moscow. In addition, over twenty articles were written about the NanoArt exhibit.

Here is a link to some of the images that we exhibited: http://www.germaninnovation.org/ news-and-events/photo-gallery/gallery?id=29

Germany clearly understands that the internationalisation of science and research is the key to competitiveness and sustainable economic growth 8

Why is the internationalisation of science and research important?

The internationalisation of science and research is important for a number of reasons. I will address a few of these here.

The ability to solve the world’s most pressing challenges, such as climate change, securing our future energy supply, and combatting poverty and infectious diseases, to name a few, requires a concerted, interdisciplinary

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© Nathalie Schueller

From left to right: Prof. György Buzsáki Dr. Joann Halpern Prof. Ursula Staudinger Prof. Eric Kandel (Nobel Laureate), at GCRI panel discussion entitled The Aging Brain

Dr Joann Halpern with Germany's president, Frank-Walter Steinmeier.

At the time of the photo he was Germany's foreign minister

effort among the world’s leading researchers.

Cross-border cooperation provides not only an expanded knowledge base, but also extraordinary opportunities for scientific advancement. National science systems do not have the capacity or financial resources to undertake the significant investment required for large-scale research facilities.

The translation of new scientific findings into new technologies is also significantly enriched through global collaboration.

Germany clearly understands that the internationalisation of science and research is the key to competitiveness and sustainable economic growth.

projects in Cameroon, Nigeria, and Yemen.

Why is the sharing of knowledge important to you personally?

Throughout my life, I have been interested in how supportive, interactive learning environments are created – for students, teachers, professors, employees, managers, NGOs, athletes and others. As a professor, I have made it a priority to create a classroom setting in which my students feel inspired to participate in discussions and share their insights.

By creating and cultivating a multidisciplinary ecosystem conducive to the cross-fertilisation of ideas, the GCRI has been instrumental in fostering partnerships between North America and Germany and encouraging interdisciplinary research publications.

Through its web presence and events, GCRI brings together scientists, business leaders, political leaders as well as media representatives to discuss and debate topics of critical importance to the world in which we live.

Within an organisational context I have found that the sharing of knowledge significantly enhances the productivity and motivation of my team. When employees have easy access to the internal resources and expertise within the organisation, they can achieve results more efficiently. In addition, being part of a functional, inclusive and collaborative team boosts enthusiasm and encourages employees to exchange knowledge, breaking down the silo mentality (when several departments or groups within an organisation resist sharing information or knowledge with other individuals in the same organisation) that can have a negative impact on morale.

In 2004, you co-founded Knowledge Transfer Beyond Boundaries, an NGO with

There are so many different ways to share knowledge - explicitly sending information,

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providing access to information created by others and verbal/digital conversations, to name a few. Sharing not only allows new information and knowledge to be produced, but it can also be reused. This, in turn, leads to more informed decision making.

Contact German Center for Research and Innovation 871 United Nations Plaza New York, NY 10017 USA. E: info@germaninnovation.org W: www.germaninnovation.org twitter.com/gcri_ny

9

Cardiovascular

The challenge of treating a stiff heart Heart failure, when the heart fails to pump blood properly around the body, hospitalises more people in the Western world than any other condition. Dr Nazha Hamdani from Ruhr University aims to unravel the biological mechanisms underlying the stiffening of heart tissue that can lead to heart failure. She plans to use the knowledge gained from her recent discoveries to investigate novel treatment options for the condition.

Her work will employ a more refined approach than has ever been trialled before, based on an understanding of the variable factors involved in each case of heart failure.

W

hen the heart beats, it contracts to push blood out of chambers known as ventricles, and then relaxes to allow the ventricles to refill with blood. The measure of how much blood a ventricle in the heart pumps with each heartbeat is known as ejection fraction (EF) and is usually measured as a percentage (normally > 50%). This value represents the proportion of blood inside the ventricle that is pumped out with each contraction. Most commonly, EF is used to refer specifically to the amount of blood that is expelled from the left ventricle – the main chamber within the heart that is responsible for pumping oxygenated blood around the body.

Heart failure (HF) can occur either with reduced or preserved EF. In cases of heart failure with reduced EF (HFrEF), the heart is not able to send the normal amount of blood out and around the body. Patients with normal ventricular EF are diagnosed as having heart failure with preserved EF, referred to as HFpEF. This means that, although the heart contracts normally to push blood out, the left ventricle is unable to relax completely, thus limiting its ability to refill with blood to full capacity.

Dr Nazha Hamdani’s recent research, based at Ruhr University, Germany, has been uncovering the mechanisms that contribute to HFpEF – the most common form of HF which makes up more than 50% of cases in Western societies.

ONE SIZE DOES NOT FIT ALL Current treatments for HFpEF elicit a poor rate of response, and previous attempts to develop new therapeutics have yielded little success. Indeed, thus far, all large scale clinical trials of potential treatments for HFpEF, including those effective for HFrEF, have failed to produce positive results. This indicates that a “one size fits all” approach to the treatment of HFpEF may not be an appropriate way of tackling the problem.

Dr Hamdani suspects that this could be due to a lack of understanding of the molecular mechanisms that are unique to each form of the disease. She thinks that therapeutic strategies which employ specific treatments for distinct subtypes of HFpEF may prove key in developing new therapies for patients.

The need to find effective solutions is increasingly pressing, as the incidence of HFpEF continues to rise. This increase is correlated with increased age and rates of

In heart failure with preserved ejection fraction, although the heart contracts normally to push blood out, the left ventricle is unable to relax completely, thus limiting its ability to refill with blood to full capacity www.researchfeatures.com

hypertension, obesity, metabolic syndrome and type 2 diabetes. The annual mortality rate is approximately 22% – a worse prognosis than for many cancer diagnoses.

Therefore, Dr Hamdani and her team also plan to assess treatment strategies for a range of these co-morbidities. Investigating the different effects of a range of factors on heart cells and the extracellular matrix will provide them with new insights into the development of therapeutic interventions.

TITIN PHOSPHORYLATION REGULATES HEART CELL STIFFNESS Dr Hamdani and her team’s recent research has focused on comorbidities that are common in HFpEF for treatment of HFpEF. Dr Hamdani thinks that the syndrome of HFpEF goes above and beyond the comorbidities. She thinks it is not just a collection of comorbidities but that those comorbidities play an integral role in driving an inflammatory process so each comorbidity creates inflammation in the body which is driving the syndrome. The team found in their recent elegant study using biopsies from HFpEF patients and animal models of HFpEF that inflammation drives coronary endothelial dysfunction through a nitric oxide pathway that decreases cyclic guanosine monophosphate (cGMP)-dependent protein kinase G (PKG).

What does this do to the heart? It leads to decreased compliance of and increased stiffness of the ventricles creating diastolic dysfunction.

The diastolic stiffness that causes the decreased relaxation capacity of the ventricle in these cases is associated with the giant protein titin. Titin forms a network of filaments in heart cells known as cardiomyocytes. In recent years, it has become apparent that titin elasticity is highly variable within the heart during development and can become altered in heart disease.

TTN, the gene encoding titin, has also been identified as a major human disease gene.

Variations in titin elasticity due to changes in genetic expression play a major role in the stiffness of cardiomyocytes, as do the modifications that occur after protein synthesis.

The team's work has revealed that the phosphorylation of titin by cGMP-PKG decreases cardiomyocyte stiffness.

Furthermore, they have been able to demonstrate that this process is impaired in HFpEF patients and animal models.

They have identified that the co-morbid

11

Cardiovascular

elements common in HFpEF contribute to inflammation and oxidative stress that drive cell dysfunction. These in turn lead to a reduction in the level of cGMP and the activity of PKG. Dr Hamdani and her team hypothesise that the impact of comorbidities, combined with other factors, including gender, affects the pathophysiology of HFpEF. They suspect that the result of the changes they have found in the cGMP-PKG pathway is one key mechanism through which this occurs.

Amount of blood in ventricle Contracted Ventricle

Next, the researchers plan to analyse the phosphorylation sites along the entire titin molecule. They aim to discover the nature of the components of the cGMP-PKG signalling cascade involved in titin phosphorylation, and therefore cellular stiffness. Dr Hamdani hopes to discover through this research a way to artificially increase cGMP concentration within cardiomyocytes, thus increasing their elasticity. She thinks this can be done through either increasing the pool of cGMP or through targeting the upstream pathway by reducing inflammation and thereby oxidative stress, which then may improve endothelial function, cardiomyocytes and extracellular activities all in one. This could prove an effective mechanism for the design of a new treatment.

HOW CO-MORBIDITIES AND COLLAGEN CONTRIBUTE TO HFpEF In addition to Dr Hamdani’s recent discoveries about the involvement of the titin protein, she also suspects that oxidative stress and inflammation lead to hypertrophy and fibrosis of the left ventricle.

The co-morbidities present with the condition raise levels of pro-inflammatory proteins in the blood and drive inflammation of cardiac vasculature. This disrupts signalling between the endothelial cells that line the small blood vessels within the heart muscle, cardiomyocytes and fibroblasts (cells responsible for the synthesis of collagen and the extracellular matrix). Immune system cells called macrophages infiltrate the inflamed tissues and secrete growth factors

Amount of blood pumped out of ventricle

Relaxed Ventricle

that drive fibroblasts to differentiate into myofibroblasts. These cells alter the amount, or form, of collagen deposition in the region, further contributing to ventricular stiffness.

Myocardial collagen is composed primarily of two types of fibres, and their ratio affects ventricular elasticity. Other mechanical factors related to collagen, including fibre geometry and cross linking, are also involved.

Changes to any of these properties can be altered in heart disease and contribute to the diastolic stiffness characteristic of HFpEF.

Current treatments for heart failure with preserved ejection fraction elicit a poor rate of response, and previous attempts to develop new therapeutics have yielded little success 12

Ejection Fraction %

GENDER ROLES Dr Hamdani and her research team hope to develop HFpEF therapy specifically designed for men or women based on the physiology and co-morbidities involved in their case of HFpEF. Obesity and a history of hypertension or renal impairment have a higher correlation in females with HFpEF than males. Women generally exhibit smaller left ventricular volumes, higher EF values and greater ventricular and arterial stiffness. In men, HFpEF is more likely to be associated with atrial fibrillation and chronic obstructive pulmonary disease.

Now, armed with an understanding of the mechanisms that underpin the heterogeneity of the condition, Dr Hamdani plans to focus on working towards developing these specialised therapeutic approaches.

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Detail What inspired you to begin working on the biology of HFpEF in particular?

This is a growing clinical problem for health care and services. However, our understanding of this condition is very limited and therefore so are our treatment options. It is the predominant form of heart failure in women, the elderly and with a lot of comorbid conditions, such as diabetes, obesity, and lung diseases and unfortunately there is no effective therapy.

So there is a strong rationality to try something different to treat these patients in hope of prolonging their lives.

Why is so little currently known about HFpEF and how to treat it, in comparison to HFrEF? We have collected information about the mechanisms of the disease over the past years, but I personally believe there are lots of subtypes of this condition. With HFrEF we were very effective in treating this condition and we were successful in reducing mortality and morbidity rates by 40% using some common treatment irrespective of the etiology.

Unfortunately, moving to HFpEF, we haven’t been successful with that strategy and therefore we need to put more effort into understanding the pathophysiology of this type of disease. I strongly believe that understanding this disease depends largely on subdividing it into subgroups of patients based on co-morbidities, age and sex differences and trying to understand the pathophysiology of every subtype. Accordingly, we will be able to personalise the treatment approaches.

Taking this approach, I am sure we will be in a good position to manage the patients of tomorrow.

How is HFpEF currently diagnosed?

Do you think these methods could be improved upon and if so how?

Clinicians are often confronted with these patients and yet have little guidance on how to effectively diagnose and manage them. In my opinion, the diagnosis of HFpEF is challenging, because the symptoms are non-specific and can be explained by several alternative noncardiac conditions. I believe the right

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diagnosis requires: determination of left ventricular ejection fraction (>50%), wall thickness (hypertrophy) and estimated pressure (increased E/e'), and diastolic dysfunction by echocardiography (e.g. decreased E/A); left atrial diameter (dilation); NT-proBNP levels; AND fatigue, dyspnoea, physical intolerance, chronotopic incompetence, with the main goal being treatment for subclasses of HFpEF according to etiology and pathomechanism.

What do you think will be the most difficult aspects to accomplish in your proposed research?

I would put this in a very simple and positive thinking way, the aim of the proposed research is to deepen our basic understanding of HFpEF pathophysiology associated with comorbidities, age and sex differences, in order to provide firm foundations for clinical innovation.

This will never be accomplished by just one group – it requires a range of expertise that is far beyond the capacity of any one group but is provided by teamwork and collaborations based on shared knowledge and a range of professional skills. The knowledge and skills intermesh perfectly to resolve the complex structural, functional, molecular, and biological interactions underlying diastolic dysfunction to achieve one goal: providing a novel HFpEF treatment and giving HFpEF patients a new lease on life.

How do you see your research progressing over the following years?

HFpEF is a very long-standing mystery, but there have been some incredible leaps forward in HFpEF research over the last years. Looking back at our achievements and our understanding even if it’s still limited, I am extremely positive that we will have more amazing scientific discoveries in HFpEF within the next few years. These will change our conception of how we see the disease and guide us to the missing puzzle piece in HFpEF that will give a boost of new life to HFpEF patients. Therefore, I can say with great confidence, we will crack the mystery of HFpEF very soon.

RESEARCH OBJECTIVES Dr Hamdani’s research looks at the biological mechanisms and potential treatment options within heart disease, particularly focused on the connections between diastolic stiffness and heart failure with preserved ejection fraction.

FUNDING Deutsche Forschungsgemeinschaft (DFG) COLLABORATORS • Prof Dr Wolfgang A Linke • Prof Dr Walter J Paulus • Prof Dr Michaela Kuhn • Prof Dr Gilles de Keulenaer • Prof Dr Johannes Backs • Prof Dr Stephan Heymans • Prof Dr Viacheslav Nikolaev • Prof Dr Carsten Tschöpe • Prof Dr Sophie van Linthout • Prof Dr Cristobal dos Remedios BIO Dr Hamdani studied Medicine and Pharmaceutical Sciences at Free University of Brussels and Amsterdam before doing her PhD at Cardiovascular Research (ICAR-VU), VU University Medical Center. Since then, she has worked in different centres of Cardiovascular Research in Europe, Germany, The Netherlands, and UK. CONTACT Dr Nazha Hamdani Department of Cardiovascular Physiology MA 2/50 Ruhr University Bochum D-44780 Bochum Germany E: nazha.hamdani@rub.de T: +49 234 32 29412 W: http://www.py.rub.de/kardp/gm/n_ hamdani.html

13

Going with the flow

Medical Physics

Measuring blood flow in vessels throughout the body can be crucial for the correct diagnosis and treatment of disease, but it is no easy task. A research group led by Dr Stefanie Demirci at the Technical University of Munich has taken on this challenge, creating novel algorithms to quantify blood flow and minimise risky surgical interventions.

T

he flow of blood around the body is essential for the transport of nutrients, hormones and – crucially – oxygen to all tissues.

Any interruption or alteration to blood flow can therefore have significant deleterious effects, and these changes can provide valuable markers of disease.

For instance, the rate of blood flow to and through the heart can be an important indicator of its condition. Tumours, such as liver tumours, can be identified based on an increased blood flow, due to proliferation of blood vessels in their vicinity. Conversely, decreased blood flow in the extremities can indicate cardiovascular problems. In the brain, measurements of blood flow can help to pinpoint the site of a stroke and identify tissues at risk of further damage.

Thus, obtaining an accurate assessment of the flow of blood within veins and arteries throughout the body can be a first step to diagnosing and treating a range of diseases.

MINIMALLY INVASIVE IMAGING As with any medical procedure, reducing surgical invasion is key to patient health in terms of reducing recovery time and the likelihood of complications. For many vascular diseases such as stroke, time is a crucial factor. Dr Demirci and her collaborators’ research focuses on fast and minimally invasive methods for monitoring blood flow throughout the body, using interventional X-ray images interpreted through computer algorithms. Having published many papers on blood flow in the brain, in a new three-year project funded by the German Science Foundation (Deutsche Forschungsgemeinschaft), and supported

by Siemens Healthineers, the team is now turning to the cardiovascular system itself.

Non-invasive techniques such as ultrasound can provide a qualitative view of blood flow, but X-ray is still the gold standard due to the large field of view.

To quantify blood flow accurately, and provide the most appropriate patient care, a high-contrast dye is added to the blood stream, via a carefully-positioned catheter.

The blood vessel in question is then visualised using an aptly-named ‘C-arm scanner’ – a C-shaped device in which one end of the C contains an X-ray source and the other, an X-ray detector. The patient is positioned inside the ‘C’, before a series of X-ray images (known as angiographs) are taken in quick succession. A computer then uses these to generate a graph of contrast through time. From this, parameters relating to the flow of blood in the vessel, such as speed and volume, are calculated.

The team around Dr Demirci has developed an algorithm using models from computational fluid dynamics, to make these calculations for cerebral blood vessels. At the same time, her system identifies the optimum timing for capturing blood flow data, based on pinpointing the arrival of the contrast dye at the point of measurement. So far, results suggest that the method can calculate blood flow with less than 12% error rates. The system can be used in ‘computer-assisted endovascular procedures’ which minimise the time spent in surgery by predicting and simulating information that could otherwise only be obtained under the surgeon’s knife.

Accurate assessment of the flow of blood within the body using interventional imaging only, could speed up diagnosis and treatment of a range of urgent vascular diseases 15

Medical Physics

PRE

Aneurism

Parent artery

POST

TCC (t)

ROI

1 FD

PSD(f)

t TCC (t)

2

3

PSD(f)

t The injection of contrast medium into blood vessels allows the visibility of blood in X-ray imaging and its characterisation by time-contrast curve (TCC) and corresponding power spectral density (PSD) in Fourier space.

The figure shows results pre and post flow diverter treatment and clearly support the clinical hypothesis that flow diversion leads to a reduction of pulsatility of intra-aneurysmal haemodynamics

of 2D and 3D blood flow visualisation are not only useful for diagnosis, but are also increasingly being integrated into treatment.

For instance, ‘flow diversion’ is a treatment for cerebral aneurysms (swellings in the wall of a blood vessel in the brain), in which a prosthetic blood vessel is inserted to divert blood flow away from the area weakened by the aneurysm. Dr Demirci and colleagues have developed a metric for quantifying blood flow before, during and after surgery, which reduces interference caused by the patient’s own heart rate, thereby providing accurate information about the success of the flow diversion treatment and aiding clinical decision-making.

Before it will be adopted in practice therefore, the increase in accuracy gained with 3D imaging must outweigh the complexity, time taken, and risks to the patient, in terms of higher doses of X-rays and contrast dyes. Together with her collaborators from industry and academia, Dr Demirci is working to develop increasingly efficient algorithms to speed up the computer interpretation of multiple 3D X-ray images, using a method known as tomographic image reconstruction.

Even more excitingly, computer algorithms may in future be used to produce virtual assessments of blood flow around the flow diverter, providing a prediction of the results prior to surgery, and enabling doctors to test alternative placements of the device to optimise clinical outcomes, without going through a risky ‘trial and error’ process within the patient.

TO THE HEART OF THE MATTER While Dr Demirci’s progress in monitoring blood flow in the brain is impressive, the brain is, in fact, one of the easiest parts of the body to work with, since it is subject to

Dr Demirci’s advances should have dramatic impacts in practical surgery, speeding up operations, and drastically improving patient recovery times 16

f Flow Centerline

MOVING UP A DIMENSION Calculating blood flow from twodimensional angiographs of a threedimensional vessel, as described above, is a difficult task requiring a good understanding of the nature of each patient’s blood vasculature. Despite this, 2D imaging is popular with clinicians due to its relatively quick and easy application. Alternative 3D techniques, which Dr Demirci and her collaborators are also developing, may be more accurate but can require patients to undergo multiple injections of contrast dye and multiple X-rays, and involve lengthy computerised interpretations of the images to calculate blood flow statistics.

NOT JUST A DIAGNOSIS The systems, processes and algorithms

f

A(l) n(l)

l The estimation of blood flow requires mathematical modelling of the vessel geometry as a tube with centerline, as well as underlying physical principles such as velocity

minimal movement apart from the flow of blood. Elsewhere in the body, interference from breathing, the heartbeat, and muscle contractions make visualising blood flow even trickier. Not to be deterred, Dr Demirci and her project partners are now working to assess blood flow in other systems, including the heart and liver. One example within this includes monitoring the success of methods that divert blood away from a tumour, by inserting a small artificial blockage, in a procedure known as ‘embolisation’.

In the cardiovascular domain, Dr Demirci is working on algorithms to improve the accuracy of ‘image registration’. This process involves merging multiple images taken at different time points to build a comprehensive picture of a structure, such as a blood vessel or heart valve – and to support accurate tracking of devices such as cardiac stents during surgery.

Her advances in software and algorithms should have dramatic impacts in practical surgery, speeding up operations, improving patient recovery times, and in some cases even avoiding the necessity for open heart surgery.

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Detail How are computers being used in medicine today?

In recent years, computers have become more and more important inside clinics, beyond hospital administration. With increasing performance and decreasing size, nowadays, computers play an important role in the diagnosis and treatment of various diseases. Supporting medical expertise, computers are able to combine various specific pieces of information about a single patient or a group of patients and give specific hints to physicians for diagnosis. During surgery, computers can again combine this data with planning sketches in order to allow for a disease- and treatmentspecific visualisation of the patient’s anatomy and physiology.

What kinds of conditions can your research help to treat?

In our research, we are aiming at solutions to aid and support doctors, physicians and surgeons so that they can fully concentrate on their job. Besides great opportunities, the appearance of computers inside medical workflows has also introduced many challenges for medical staff. We try to develop smart machines that provide necessary information at the right time without requiring too much interaction. In this specific research topic quantifying blood flow, we are focusing on cardiovascular diseases such as stroke, arteriovenous malformation (AVM) and coronary artery disease.

What is the difference in approach between 2D and 3D imaging of blood flow, and what are the advantages of the latter?

In conventional clinical practice, blood flow is measured using diagnostic X-ray imaging methods such as Computed Tomography. In urgent cases (such as stroke), time is crucial and physicians would like to eliminate the necessity for a diagnostic scan. Instead, they would like to be able to use interventional X-ray imaging for measuring the true volumetric blood flow. Our research is a first step in this direction. The

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biggest challenge here is to move from volumetric scans showing a 3D anatomy of the body, to projection X-ray images that are acquired by interventional machines. We have proposed novel solutions that calculate an estimated volumetric blood flow from 2D projection images only. Interventional 3D imaging is possible, but not performed as standard due to its increased radiation dose.

If applied, however, our method for calculating the true volumetric blood flow is more accurate.

What are some of the additional challenges to measuring blood flow elsewhere in the body compared to in the brain?

The cerebrovascular region is hardly affected by any sort of motion. Breathing as well as organ specific motion is not present in this anatomical area and patient motion such as moving of the head can easily be detected by imaging systems. The cardiovascular region, however, is subject to various motion types such as breathing motion, heartbeat, and motion by the gastrointestinal tract. These motion types are very specific and may divert from their known pattern due to disease and patient stress. Algorithms that have been invented for the cerebrovascular region are not easily transferable to other anatomical regions of the human body without further research to solve the above-mentioned challenges.

How do you envisage computerassisted methods moving forward over the next five to ten years?

Over the upcoming decade, computers in clinics will transform from bulky machines towards smart, invisible systems that are embedded within each single clinic device ranging from a simple patient bed to a single lamp within the OR unit. Clinics will be equipped with such smart devices allowing for diseaseand treatment-specific assistance portfolios depending on the application scenario they are placed within.

RESEARCH OBJECTIVES Dr Demirci’s work aims to provide quantitative methods of measuring personalised blood flow from interventional images. Her current research focuses largely on biomedical imaging and image processing.

FUNDING Deutsche Forschungsgemeinschaft (German Science Foundation): Grant-No.: 288973636 COLLABORATORS •P D Dr-Ing Markus Kowarschik (Siemens Healthineers) •D r med Reza Ghotbi (Helios Clinical Center Munich-West/Dachau) •P rof Dr Bjoern Menze (Technical University of Munich) •P D Dr-Ing Gabor Janiga (Otto-von-Guericke University Magdeburg) BIO Dr Stefanie Demirci received her PhD from the Technical University of Munich in 2011 for her work on novel approaches to computer assisted endovascular procedures. She is currently co-managing the Computer Aided Medical Procedures (CAMP) lab focusing on biomedical imaging, image processing and biomedical gamification.

CONTACT Dr Stefanie Demirci, Research Manager Computer Aided Medical Procedures & Augmented Reality Technische Universität München Institut f. Informatik 16 Boltzmannstr. 3 85748 Garching b. München Germany T: +49 89 289-19405 E: stefanie.demirci@tum.de W: http://campar.in.tum.de/Main/ StefanieDemirci

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Mycology: unravelling the riddle of the filamentous fungi The fungi are perhaps the least understood of the multicellular organisms, despite being almost ubiquitous in nature. An international team, coordinated by Professor Dr Reinhard Fischer of the Karlsruhe Institute of Technology, Germany, and Professor Dr Meritxell Riquelme from the Centro de Investigación Cientifíca y de Educación Superior de Ensenada, Mexico, is leading attempts to understand the growth and development of these remarkable organisms, shedding light on their medical and ecological applications.

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T

here may be as many as five million species of fungi worldwide – many more than there are plants. The vast majority of these littleunderstood organisms are the ‘filamentous fungi,’ named because they are composed of a web of filaments called ‘hyphae’.

The work of Professor Fischer, Professor Riquleme and their co-workers focuses on how these filaments grow, indefinitely, by

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Microbiology

Left: The picture shows different colour mutants of Aspergillus nidulans. Wild type forms green spores which cover almost the entire colony. It is easy to generate mutants in which pigment biosynthesis is blocked at certain stages and thus a different pigment variant (yellow) or no pigments (white) are produced.

Mutants are a great starting point for a molecular analysis. This approach has been used to study many cellular processes and made A. nidulans, a model organism for lower eukaryotes and beyond. The diameter of a colony is about 1 cm.

less well-known is that they play a vital role, not only in generating nutrients, but also in plant nutrient uptake: every metre of plant root in the soil is associated with roughly a kilometre of symbiotic fungal hyphae, known as ‘mycorrhiza’, which take up nutrients and pass them to the plant.

Filamentous fungi are important pathogens of crop plants, and in a few cases cause serious human disease, particularly in the immunocompromised. They have also been harnessed for biotechnological uses, including crucially in the production of antibiotics such as penicillin, other medicines, citric acid, and foods such as soy sauce and cheese. To scientists, fungi are also important due to the similarity of their cells to human cells, making them ideal models to study various aspects of cell function.

Professor Fischer, Professor Riquelme and their colleagues, with funding from the Deutsche Forschungsgemeinschaft and CONACYT, are studying a host of questions surrounding the growth and development of filamentous fungi. Using multiple species and state-of-the-art microscopy and molecular biological methods, they are enhancing our understanding of the mechanisms by which these intriguing and important organisms grow and differentiate.

extension at each microscopic tip, to form huge networks called ‘mycelia’.

UNDERRATED ORGANISMS Despite their lowly appearance, the filamentous fungi are crucial to the functioning of natural ecosystems. Alongside bacteria, they are the main agents responsible for decomposing dead organic matter, making its chemical components available to the next generation of organisms. What is perhaps

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KEEPING PACE WITH GROWTH At the tip of each fungal hypha lies a region of active growth. Here, membrane-bound particles (vesicles) containing the raw materials for building new cell walls and membranes – proteins, lipids and other organic molecules, as well as catalytic enzymes – fuse with the cell’s boundary membrane, releasing their precious cargo. However, the highly polarised positioning of this region poses challenges for the fungus. Firstly, how can they transport

Above: With the help of the jellyfish green fluorescent protein (GFP) researchers visualised the microtubule cytoskeleton in Aspergillus nidulans. Round spores produced long hyphae, and microtubules are visible as long filaments in the cells. They serve as tracks for intracellular traffic. Picture taken by Minoas Evangelinos, KIT.

adequate quantities of these materials to the tip in order to keep up with the rate of growth? Secondly, with such rapid growth occurring at the tip, how does the hypha maintain a stable marker of exactly where, and in what direction, growth is to occur?

The logistics of transporting materials to the actively-growing hyphal tip are being elucidated by Michael Feldbrügge’s lab at Heinrich Heine University, Düsseldorf, Germany. The length of the hyphae is traversed by a skeleton of fine tubes called microtubules, along which vesicles and their contents travel, facilitated by proteins acting as motors. Feldbrügge has also found that these provide transport routes for molecules of messenger RNA, which translate the genetic information in DNA into functional proteins. Crucially, this means that protein production can be precisely targeted to specific regions within a cell without having to transport large quantities of the proteins themselves.

The diverse and enlightening findings of this high-profile programme have implications far beyond the fungal 19

Microbiology

2 µm Above: In this experiment two enzymes required for cell wall synthesis were visualised in hyphae of Neurospora crassa using two different coloured fluorescent proteins. Whereas an endoglucanase enzyme (BGT-2) localises to the plasma membrane, a chitin synthase (CHS-1) accumulates first in a structure called “Spitzenkörper” before it is secreted. Confocal Laser scanning microscopy images obtained by Dr Leonora Martínez-Núñez, CICESE.

In answer to the second question, Prof Fischer himself, working with Prof Norio Takeshita, has discovered that in the filamentous fungus, Aspergillus nidulans, molecules of a special protein – TeaR – located at the tip of the hyphae, mark the zone in which active growth is taking place. Using advanced, super-resolution microscopy techniques to visualise the activities of living cells in real time, they showed that the cluster of TeaR molecules at the hyphal tip is repeatedly dispersed and reassembled with newlyarriving TeaRs, maintaining an indicator that tells the machinery of the cell where to build new tissue.

Close-up images of a colony of N. crassa. The aerial mycelium shows the interwoven fine hyphae.

Carotene stains the mycelium orange. Pictures taken by Rosa Aurelia Fajardo Somera from KIT.

A further project, led by Prof Meritxell Riquelme is shedding light on the precise nature of the transport of vesicles found at the growing hyphal tip. Remarkably, it turns out that there are separate populations of differently-sized vesicles carrying different enzymes for building various components of the fungal cell wall.

FROM REPAIR TO REPROGRAMMING In addition to spontaneous growth, organisms also need to repair themselves from damage, and research into filamentous fungi is shedding light onto how this may be achieved.

Prof Alfredo Herrera-Estrella at the Laboratorio Nacional de Genómica para la Biodiversidad, Guanajuato, Mexico, and colleagues, use the fungus Trichoderma atroviride, a biocontrol agent, in their work. They have shown, using modern genetic approaches,

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1cm

State-of-the-art microscopy and molecular biological methods are enhancing our understanding of the mechanisms by which these intriguing and important organisms grow and differentiate www.researchfeatures.com

Detail How numerous, widespread and significant are the filamentous fungi?

Fungi are found in nearly all ecosystems, where they fulfil important functions for nutrient recycling. Some species are important plant pathogens, such as Magnaporthe oryzae or rust fungi. There are also animal pathogens.

Many moulds contaminate food and feed and cause tremendous losses due to mycotoxin formation.

Why is their growth and development such an interesting area to study?

The fungal hypha is able to grow indefinitely at the tip. It is one of the few examples of extreme polar growth of individual cells. Other examples are pollen tubes, root hairs and nerve cells.

Thus the study of the mechanisms of polar fungal extension may help to improve our understanding of polarity in general. Likewise, simple hyphae are able to differentiate rather complicated structures such as fruiting bodies.

This requires massive changes in gene expression. It can be an example for other differentiation processes, e.g., embryogenesis in higher eukaryotes.

that injury results in the production of highly reactive and damaging molecules known as ‘reactive oxygen species (ROS)’, stimulating the formation of reproductive structures.

This molecular pathway promotes cell differentiation and regeneration in the face of damage and – using ROS as signals – could be shared with both plants and animals.

Therefore, understanding it could have important applications in medicine.

Also working at the Karlsruhe Institute, Prof Natalia Requena is studying how filamentous fungi interact with plants when forming arbuscular mycorrhizal symbioses, which improve the plants’ supply of phosphate, sulphur and nitrogen in return for carbohydrates. Within roots, the fungi form specialised structures known as ‘arbuscules’ to allow the nutrient exchange between symbiotic partners. Arbuscule

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What recent technological advances have helped further your research?

The advent of molecular biological methods in the 1980s, the use of GFP and other fluorescent proteins since 1994 in combination with steadily improved microscopy techniques and the recent development of super-resolution microscopy techniques have boosted fungal research.

How do the cells of filamentous fungi differ from those of other organisms?

Fungi are in many aspects identical to human cells. One important difference, however, is the presence of a rigid cell wall consisting of different carbohydrate polymers, including chitin. Because of this difference, the fungal cell wall or the biosynthesis machinery may be targets for drug development.

What biological features are conserved between filamentous fungi and animals such as humans?

Basic cell biological processes such as mitosis, meiosis, the functioning of organelles, or the principles of gene regulation, are highly conserved between humans and both filamentous

formation, however, requires the fungus to both circumvent plants’ natural defences and to emit signals that actively reprogramme the plant cells to accommodate arbuscules. As molecular biology advances, and the genomes of filamentous fungi are sequenced, our understanding of the precise molecular nature of these interactions will unfold.

FROM FUNGI TO FURTHER AFIELD The diverse and enlightening findings of this high-profile programme have implications far beyond the fungal kingdom. The methods used – particularly novel ways of imaging microscopic and rapidly-changing structures – have the potential to revolutionise studies of subcellular processes across the living world.

Professor Fischer and his collaborators are finally bringing the filamentous fungi from the soil firmly into the limelight.

RESEARCH OBJECTIVES Professor Reinhard Fischer is currently studying the filamentous fungus Aspergillus nidulans. His primary interest in this fungus is as a model for spore and mycotoxin formation and the effect of environmental factors on its growth.

Professor Meritxell Riquelme is studying the mould Neurospora crassa and is interested in the cellular components enabling indefinite hyphal extension.

FUNDING Deutsche Forschungsgemeinschaft (DFG) Consejo Nacional de Ciencia y Tecnología, Mexico (CONACYT) COLLABORATORS Professors J Aguirre, M Bölker, G Braus, M Feldbrügge, U Fleig, W Hansberg, A Herrera-Estrella, R Mouriño-Pérez, J Kämper, U Kück, N Requena, N Takeshita, S Bartnicki-Garcia BIO Before becoming Professor for Microbiology at the University of Karlsruhe, Prof Dr Reinhard Fischer studied for his PhD in Microbiology at the University of Marburg. He has represented the DFG as a panel member since 2012 and sits on the editorial boards for a number of well-known scientific journals, including Molecular Microbiology, mSphere and mBio. Prof Dr Mertixell Riquelme completed a BS in Biology at the University of Barcelona, Spain and a PhD in Microbiology at the University of California, Riverside. She has worked at the Scientific Research Center and Higher Education of Ensenada (CICESE) in Baja California, Mexico since 2004.

CONTACT Prof Dr Reinhard Fischer Karlsruhe Institute of Technology (KIT) Institute for Applied Biosciences Dept. of Microbiology Fritz-Haber-Weg 4, D-76131 Karlsruhe Germany T: +49-721-608-44630 E: reinhard.fischer@kit.edu W: www.iab.kit.edu/microbio

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Health

Novel mouse models reveal molecular details of skin cell death Dr Panayotova-Dimitrova’s recent work has identified a key regulator of skin homeostasis and its exact mechanisms. To elucidate this, her team employed a novel approach, using mouse models. These models enabled the researchers to dissect the role that a protein called cFLIP plays in regulating cell death in the skin, providing fresh insights into life-threatening skin diseases.

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t the University of Aachen, Germany, Dr Diana Panayotova-Dimitrova leads a research group investigating the regulation of cell death pathways in the skin. Her recent work has focused on generating transgenic mouse models capable of analysing cellular FLICElike inhibitory protein (cFLIP) in the skin, due to the major role it plays in cell death signalling.

A strong expression of the cFLIP protein in the basal layer of the human skin had been previously established by the group, indicating that cFLIP may play an important role in the development and maintenance of this tissue. Combining these factors also led the researchers to hypothesise that loss of cFLIP in skin cells may be a factor in the onset of deadly diseases related to skin cell death.

MOLECULAR PLAYERS IN CELL DEATH PATHWAYS cFLIP is a regulator of apoptosis – the process of programmed cell death in response to a stress trigger or signals from

other cells. Another mechanism for cell death is necroptosis, which is a form of inflammatory necrotic cell death that the cell undergoes in a regulated manner. This is in contrast to necrosis, which is uncontrolled by the cell and occurs due to cellular damage or infection.

In addition to regulating the apoptotic pathway, cFLIP has also been shown to induce cell necroptosis and activate pathways associated with inflammation.

Caspases are enzymes that are key players in the activation of the cell death pathway. cFLIP is a regulator of one of these essential controllers of cell death – Caspase-8 – in skin cells known as keratinocytes. These cells account for the majority of cells in the outer layer of skin called the epidermis, with around 90% of this layer made up of keratinocytes. cFLIP and Caspase-8, along with an adaptor protein (FADD), constitute a death-inducing signalling complex which forms upon activation of the death receptor.

CELL SPECIFIC GENETIC MANIPULATION Conventional analysis of gene function is

Prior to Dr Panayotova-Dimitrova’s work, virtually nothing was known about the function of cFLIP in the skin in vivo www.researchfeatures.com

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Health

Using novel mouse models, Dr Panayotova-Dimitrova’s work has revealed the mechanistic importance of cFLIP in maintaining the health of epidermal skin cells and regulating skin inflammation based on using transgenic animals where the gene of interest is either deleted or expressed in a modified form across all cells. In recent years, research employing transgenic animals has become more refined with the development of a technique for inducing these changes in a cell-specific manner. Gene function analysis can now be carried out at the level of individual cell types, as opposed to being limited to the organism as a whole. This is facilitated

by Cre/loxP system-based technology, which Dr Panayotova-Dimitrova and her team have used to create their specialised transgenic mice. Cre-Lox recombination allows for DNA to be modified in target cell types, and for this modification to be consequently triggered by a specific inducer, applied externally. It is this process

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that Dr Panayotova-Dimitrova has used to investigate the function of cFLIP, specifically in keratinocyte skin cells.

Prior to Dr Panayotova-Dimitrova’s recent work, virtually nothing was known about the function of cFLIP in the skin in vivo. This was because both conventional mouse models and those lacking cFLIP in the skin from birth have a lethal embryonic phenotype, meaning that further analysis was not possible.

Fortunately, by using novel mice models, in which the cFLIP gene could be deleted after the mice had reached adulthood, the researchers were able to circumvent this obstacle. cFLIP’S ROLE IN SKIN CELL DEATH Dr Panayotova-Dimitrova and her team’s

study of transgenic mice which lacked expression of the gene from birth, resulted in embryonic lethality – indicating the crucial role cFLIP plays in tissue development.

Where the cFLIP protein was removed in the skin of adults, the skin became severely inflamed, exhibiting blisters, pustules and skin loss. The researchers managed to ascertain that this was associated with caspase activation and apoptotic, not necroptotic, cell death. They also found that the apoptosis of epidermal cells that occurred in the absence of cFLIP, was dependent on autocrine tumour necrosis factor, the production of which is triggered by the loss of cFLIP. This discovery brings with it important insights into human disease. They have found that the same loss of cFLIP is associated with severe drug reactions linked to epidermal apoptosis, such as toxic epidermal necrolysis (TEN). TEN is a severe and often fatal drug hypersensitivity reaction of the skin where excessive cell death occurs. The disease is rare, which has made understanding it more difficult. Although discoveries over the past decade have hinted at details of its pathology, the mechanism behind the reaction within the skin has eluded scientists.

To date, there is no efficient treatment for

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Detail Could you tell us a bit about your prior research that led you to working on cFLIP? I started my research on cell death signalling when I joined the group of Prof Martin Leverkus in 2007. Martin was a great mentor and outstanding scientist. He was especially interested in the regulation of cell death resistance and I was immediately fascinated by his enthusiasm working on the analysis and manipulation of cell death. The main interest of Martin’s work was the regulation of death-receptor-induced apoptosis in general and with a specific focus on the role of the regulatory proteins cFLIP and cIAPs in this process.

My first project was related to the characterisation of cFLIP’s role in dendritic cells’ maturation. When I started to work on the development of in vivo models with epidermal cFLIP deficiency, it soon became clear that I would concentrate all my efforts on this research.

What were the biggest challenges you faced in successfully developing your novel transgenic mice?

Developing and optimising the best tools for appropriate and reliable characterisation of our model was sometimes difficult.

What types of therapeutic interventions do you think could be developed to treat skin diseases such as TEN? As we have shown in our study, cFLIP deletion leads to inflammatory and TNF-dependent keratinocytes apoptosis.

Furthermore, cFLIP deletion in patients

TEN, and the mortality rate remains high at around 30%.

DEVELOPING LIFE-SAVING THERAPEUTICS The phenotypes of cFLIP-deficient mouse skin closely resembled TEN skin in humans, and cFLIP loss had been already documented in patient skin cell samples. Using these novel mouse models, Dr Panayotova-Dimitrova’s work has revealed the mechanistic

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with TEN is a possible prerequisite for the fulminant cell death characteristic for this disease. These facts suggest that components, which interfere functionally with TNF signalling, such as TNF antagonists, might provide potential treatment for patients with toxic epidermal necrolysis. It was actually shown in a clinical study done by Paradisi et al in 2014 – a small group of TEN patients was successfully treated with a TNF antagonist.

What to you has been the most enjoyable aspect of being involved in this research?

Developing and analysing a new in vivo model can have some disadvantages.

For example, in vivo experiments are much more time consuming compared with those done in vitro.

However, waiting for confirmation of your hypothesis, building on in vitro data, and translating it to living organisms increases the excitement and the fun of working on such a project.

Where do you plan to take your research following on from this project?

We are already developing new mouse models which should help us to investigate the impact of the Ripoptosome and its downstream signals, on spontaneous and induced cell death in the skin in the context of cFLIP and its isoforms. We are also studying the involvement of additional signalling cascades, which may be involved in the development of the dramatic skin phenotype upon cFLIP deletion.

RESEARCH OBJECTIVES Dr Panayotova-Dimitrova’s research focuses on the regulation of cell death pathways in the skin. Her recent work has specifically looked into the role of the Caspase-8 regulator, cFLIP, in keratinocytes within novel mouse models.

FUNDING Deutsche Forschungsgemeinschaft (DFG) (Grant nos. Le953/6-1 and 8-1) COLLABORATORS • Tom Luedde, MD (University Hospital Aachen) • Metodi Stankov, PhD (Hannover Medical School) • Markus Rehm, PhD (University Stuttgart) BIO Dr Panayotova-Dimitrova received an MS in Molecular Biology before undertaking a PhD in Virology. During 2007, she joined the laboratory of Prof Martin Leverkus where she began studying the regulation of cell death. Last year, following Prof Leverkus’ unexpected death, Dr PanayotovaDimitrova took over and now leads the lab there.

CONTACT Dr Diana Panayotova-Dimitrova Klinik für Dermatologie & Allergologie Universitätsklinikum der RWTH Aachen Pauwelsstr. 30 D-52074 Aachen Deutschland T: +49 (0)241-80 37814 F: +49 (0)241-80 82413 E: Diana.PanayotovaDimitrova@ukaachen. de

importance of cFLIP in maintaining the health of epidermal skin cells and regulating skin inflammation. She and her team believe that cFLIP may be an effective target for therapeutic intervention to prevent excessive apoptosis – a characteristic of conditions such as TEN. Their novel insights pave the way for further research into understanding the impact of cFLIP loss, bringing with it the possibility of developing life-saving targeted therapeutics for numerous skin diseases.

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Thought Leadership

DAAD: Change by academic exchange The German Academic Exchange Service (DAAD) has been pivotal in providing millions of students and scientists with grants to further their scientific research. The DAAD is a joint organisation of German institutions of higher education and their student bodies, devoted to internationalising the academic and scientific research system. Under the leadership of DAAD’s President, Prof Dr Margret Wintermantel, the DAAD continues to improve the prospects of both German students and foreign students living in Germany, by implementing change by academic exchange.

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ack in 1922, Carl Joachim Friedrich was a 21-year-old Social and Politics student from Heidelberg, a small town in Germany. During a visit to the United States that same year, he, together with the Institute of International Education (IIE), prepared scholarships for 13 German students of Social and Political Studies – a course he was also studying at the time. On his return to Heidelberg, he opened a 'Political Studies Exchange Office' which, shortly after, became known as the 'Akademischer Austauschdienst' or the AAD.

scientific exchange across the globe.

Their motto – “Change by Exchange” – exemplifies the work that they do: awarding competitive, merit-based scholarships for students and researchers at institutions of higher education in Germany. Not only that, but the DAAD also awards grants to German students undertaking their studies and research abroad. For example, back in 2016 the DAAD funded 131,229 scholars across the world – comprising 55,754 foreigners and 75,475 Germans.

Several years later, in 1931, the AAD merged with both the German Academic Foreign Office of the Association of German Universities and the Alexander von Humboldt Foundation to form the ‘Deutscher Akademischer Austauschdienst’, otherwise known as the German Academic Exchange Service or DAAD.

The DAAD’s main headquarters are based in Bonn in Germany, but there are 15 other regional branch offices around the world, which tailor funding towards students within that region. So, for instance, the New York office funds American students to carry out their work in Germany but, likewise, it also funds German students studying at universities within the New York region of their office.

FROM 1925 TO 2017 Fast-forwarding 92 years that have passed since then, the DAAD has become a prominent funder of all German-related

MEET THE PRESIDENT Prof Dr Margret Wintermantel is the current President of the DAAD. Following her role as the President of Saarland

In 2016, the DAAD funded 131,229 scholars across the world – 55,754 foreigners and 75,475 Germans 26

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Prof Dr Margret Wintermantel. "Our work focuses on providing talented individuals the opportunity to pursue university studies or advance their research careers"

University, she was elected President of the Hochschulrektorenkonferenz (HRK), or the Rector’s Conference, in 2006. She stayed there for six years before, in 2012, becoming the President of the DAAD, following the death of Prof Dr Stefan Hormuth – the DAAD’s President at the time.

Since 2012, Prof Dr Wintermantel has been responsible for the DAAD’s active involvement in internationalising the German universities, working alongside the German government to send German students and

1925 AAD is founded by Carl Joachim Friedrich.

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researchers abroad and to accommodate foreigners. The most notable and recent example has been the DAAD’s help for young Syrians who want to study.

See overleaf for an exclusive interview with Prof Dr Wintermantel.

REFUGEE CRISIS Back in 2014, the DAAD and the German Ministry of Foreign Affairs worked together to launch a programme called 'Leadership for Syria'. The programme is specifically geared to young people who have had

1931 AAD merges with the German Academic Foreign Office of the Association of German Universities and the Alexander von Humboldt Foundation to become the DAAD.

to interrupt their studies or could not commence them due to the war. A sound education gives them future perspectives and prepares them for the task of helping to shape the Syria of tomorrow. In line with this, the DAAD funded 271 Syrians (either from Syria itself, or a bordering country) with scholarships to study at various universities throughout Germany – ensuring their safety from the war.

Not only that but, rather than hideaway from the massive influx of refugees in 2015,

1943 All of DAAD's files were destroyed during World War II on the night of 22nd November

1946 - 1948 Steps were taken to restore the DAAD.

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Thought Leadership

The DAAD is an organisation which understands the importance of exchanging ideas and opportunities, to implement positive change on the world

And thirdly, it hopes to focus on creating and maintaining the structures that make academic exchange and mobility possible – living up to their motto: “Change by Exchange”.

The DAAD's main task is much broader than providing education for refugees. As their website states: “The DAAD supports the internationalisation of German universities, promotes German studies and the German language abroad, assists developing countries in establishing effective universities and advises decision makers on matters of cultural, education and development policy.”

In other words, providing scholarships, experiences and programmes to the betterment of both German students and Germany as a whole, remains the DAAD’s top priority. Through Prof Dr Wintermantel’s tireless leadership, the organisation has already funded more than 1.9 million scholars both in Germany and abroad, and that does not appear to be slowing down any time soon.

Prof Dr Wintermantel and the DAAD rose to the challenge, developing a four-year package alongside the Federal Ministry of Education and Research (BMBF) to make it easier for refugees to gain access to higher education. They also actively promote engagement between German students and refugees, by waiving examination fees for them and teaching them how to speak the language, to ensure that their integration within German society is as straightforward as possible.

STRATEGY 2020 The DAAD’s “Strategy 2020”, released in 2013, outlines the ways in which the organisation hopes to continue their previous success, but also builds on that, emphasising the need to cope with new challenges. This includes three key action areas: “Scholarships for the Best”, “Structures for Internationalisation” and “Expertise for Academic Collaborations”.

Firstly, the DAAD aims to utilise its experience and expertise to continue providing scholarships to both German and foreign students. Secondly, it aims to provide information and advisory services to institutions of higher education and other academic exchange stakeholders, both in Germany and abroad, and hopes to expand its already unique worldwide network.

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1952 The British military expresses its wish to have a German organisation as the central contact partner for academic exchange matters.

Shortly afterwards, the DAAD was re-established, operating from its headquarters in Bonn, Germany.

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The DAAD regional office opens in London.

The DAAD represents a fantastic organisation, demonstrative of the ruthless efficiency many associate with Germany – the organisation’s work on the refugee crisis and its dedication to ensuring educational development for all students, regardless of nationality, exemplifies this. With Prof Dr Wintermantel at the helm, the DAAD is an organisation which understands the importance of exchanging ideas and opportunities, to implement positive change on the world.

If you would like to find out any more information about the DAAD or the extensive range of programmes it offers, please visit their website at www.daad.de.

Q&A WITH PROFESSOR DR MARGRET WINTERMANTEL, PRESIDENT OF THE DAAD Hello Professor Wintermantel! Could you tell us about what your role as President of the DAAD involves and what kind of responsibilities you have?

As President of the DAAD, it is my responsibility to represent the DAAD in all organisation-related matters. I serve as the chairperson of the Executive Committee, prepare its deliberations and resolutions, and ensure their implementation. I also chair the meeting of the Board of Trustees and the General Assembly. My responsibilities include appointing the Secretary General following confirmation by the Executive Committee and supervising the management of the organisation.

Fostering international academic cooperation is one of the DAAD’s key aims.

How does the DAAD achieve this? What other aims does the organisation have?

The DAAD supports the German universities and their international partners in their commitment to development policy. The instruments developed for this purpose have proven effective and sustainable. Through the linking of individual and institutional

1963 The DAAD regional office opens in Paris.

1971 The DAAD regional office opens in New York.

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promotion, the DAAD is extremely wellpositioned for reacting appropriately to the needs of its partners and scholarship recipients. The motto of the DAAD is “Change by Exchange” – and not only does it apply to the students and researchers we support, but to the DAAD itself. A challenge we successfully meet every day.

The DAAD is currently carrying out multiple projects. What are the key focuses for the organisation over the next two years?

The programme portfolio of the DAAD is quite large and varied. We continue to support the internationalisation activities at German universities by funding partnership projects. We also react flexibly to political developments – right now, for example, we are intensively cultivating collaborations with Africa, the Middle East, Cuba, Iran and China. In terms of thematic focus, we are developing new funding instruments for digitalisation.

Practical orientation also continues to be an important topic. The key issue here is how to make practice-oriented or dual degree programmes more international – especially those offered at universities of applied science. It turns out that in many countries, such as China for example, there is a great interest in the German models of practical orientation.

How influential has the DAAD been on scientific research since it was first established in 1925? Are there any achievements that really stand out for you?

Between 1996 and 2014, the DAAD financed 4,907 long-term lectureships, mostly in Africa and the Middle East. These were supplemented by more than 15,500 DAADfinanced short-term lectureships in the same period.

From 1950 to 2014, the DAAD has helped finance a total of 69,023 research visits for individual university professors and instructors. During this time, more than 17,500 DAAD lecturers actively taught at foreign universities in over 110 countries around the world, getting young people very excited about German Studies and “German as a Foreign Language”. (Source:

1975 The DAAD celebrates its 50th anniversary (of the original DAAD).

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catalogue on the 90th anniversary of the DAAD, p 124 ff.).

Since 2006, the DAAD has organised annual Science Tours to give international researchers the opportunity to find out more about research in Germany. Could you tell us a bit more about this? How important has this initiative been in encouraging research collaboration between Germany and its international partners?

The format “Science Tour” is targeted at foreign scientists, offering them a comprehensive insight into the German science and research system while focusing on their personal research area. By changing the scientific and regional focus with each tour, the whole spectrum of German science is covered. Participants are selected through an open and competitive

selection procedure. After receiving detailed information on funding opportunities, they get to meet and talk with renowned scientists from the same research area at various institutions. This ensures the best starting conditions for future cooperation.

Exploring Germany as part of a group of fellow researchers is a most rewarding experience and positively influences their view of Germany in the long term.

Through the Higher and Further Education Opportunities and Perspectives for Syrians project (HOPES), the DAAD is currently financing higher education scholarships for Syrian refugees in Turkey and the Middle East. Why is it important to provide opportunities in science and research for young Syrian academics?

There is a risk that a whole generation of

There is a risk that a whole generation of young people will not receive a proper education and, therefore, not be able to build a life for themselves

1980 German parliament passed a resolution mandating the DAAD to become a comprehensive advising centre for all interested students and researchers.

1999 The number of scholarship recipients increases to over 60,000 – a new record.

2000

2003

The DAAD celebrates its 75th anniversary.

The DAAD regional office opens in Hanoi, Vietnam.

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Thought Leadership

DAAD is developing new funding schemes to attract international researchers and strengthen their relationship to Germany. A good example is Postdoctoral Researchers International Mobility Experience (PRIME), the DAAD’s programme for outgoing post-docs. It is open to applicants of all nationalities, but after funding ends, all scholarship recipients spend a six-month integration period in Germany in order to foster a strong relationship to our country.

young people will not receive a proper education and, therefore, will not be able to build a life for themselves. With its support of individuals and institutions, HOPES is helping to give these young people the prospect of a better future and that will be needed for the reconstruction of Syria which will hopefully start soon. The project benefits from the relations the DAAD and its partners have cultivated in the region over the past decades.

Earlier this year, the DAAD was awarded the Institute of International Education's (IIE) Europe Award for Excellence in recognition of its accomplishments in the internationalisation of higher education.

How do you feel about the DAAD winning such a prestigious award? Do you think enough is being done to encourage international academic mobility?

The DAAD was delighted to win this award, especially because the IIE historically supported the DAAD from the very beginning, indeed, the first DAAD scholarships for German students and young researchers were granted in 1925 by the IIE. Indeed, we were very proud and honoured to learn that the IIE presented us with the Europe Award for Excellence in recognition

2004 DAAD alumni Wangari Maathai receives the Nobel Peace Prize, recognising the importance of DAAD’s work.

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of our accomplishments within the area of internationalisation of higher education.

We believe that even more should be done to encourage international academic mobility as the global challenges we face today can only be met by drawing on the expertise of well-prepared, outstanding scientists and decision makers who have had personal experience with other cultures and are accustomed to achieving solutions in international teams.

How do you see the landscape of international scientific research changing over the next ten years? What strategies will the DAAD be putting in place to facilitate future developments?

The research landscape is undergoing far-reaching changes due to the rapid development of research quantity and quality in Asia, especially China. This region will attract more and more researchers.

For young researchers who are looking for long-term positions at well-equipped institutions, geography cannot be an issue.

In fact, nowadays researchers are mostly globally mobile.

And finally, from a more personal perspective, your research as a social psychologist has included some fascinating studies in the field of psychology and psycholinguistics, as well as on the state and development of the higher education system. Given your current leadership commitments, do you still have time for hands-on research?

I’ve had to put aside my research due to my numerous responsibilities at the DAAD, which fortunately involves a lot of travelling.

My many visits abroad with our German delegations and also on my own when working with our partners on location, have been professionally and personally enriching to me because I strongly value the personal exchange with people from different cultures. This is what gives me tremendous energy.

Contact German Academic Exchange Service (DAAD) Bonn Headquarters Deutscher Akademischer Austauschdienst e.V. (DAAD) Kennedyallee 50 D-53175 Bonn Germany T: +49 228 882-0 F: +49 228 882-444 E: postmaster@daad.de W: www.daad.de

To participate in this “brain circulation”, the

2011

2013 Prof Dr Margret Wintermantel replaces Prof Dr Stefan Hormuth as the current president of the DAAD.

2015 DAAD’s ‘Strategy 2020’ is released.

Programmes are put in place to deal with the Syrian refugee crisis.

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Chemistry

How to trace glycoproteins in living cells? Metabolic glycoengineering provides the answer Carbohydrates, through the process of glycoconjugation, play a vital role in a number of important eukaryotic cell signalling processes.

Professor Valentin Wittmann and his team at the University of Konstanz focus their research on the mechanisms behind this, using metabolic glycoengineering techniques to enable the identification of particular interactions.

METABOLIC GLYCOENGINEERING TO VISUALISE CELL REACTIONS Professor Valentin Wittmann and the Wittmann research group at the University of Konstanz are employing a variety of methods to identify such underlying

functions. Having obtained his PhD from the Technical University of Munich, Professor Wittmann joined the University of Konstanz in 2003. Since 2016, he has been acting as the Head of the Department of Chemistry and Vice Coordinator of the Collaborative Research Center SFB 969. As part of his

N-Linked Glycosylation Carbohydrate

Protein

HOCH2 H O

H

O

OH

H

H

NH C

NH

O

C

C CH2

CH NH

H N-Linkage O

CH2

The Wittmann Group uses metabolic glycoengineering techniques to accomplish the integration of functional groups into the carbohydrate portion of a glycoprotein www.researchfeatures.com

O

Asparagine

C

arbohydrates are part of a variety of important biological signalling functions in eukaryotic cells. Through the process of glycosylation, carbohydrates are covalently bonded to macromolecules such as lipids or proteins.

Such post-translational modification serves a variety of purposes, including facilitating the structural stability of proteins and correct folding patterns. Glycosylation also enables an immunological response via cell–cell adhesion, although research is only now beginning to understand the biological functions behind this.

research, he examines carbohydrate–protein interactions and how glycosylation modifies a protein’s function such as its structural stability and folding, enzymatic activity and localisation.

The Wittmann Group uses metabolic glycoengineering techniques to accomplish the integration of functional groups into the carbohydrate portion – glycan – of a glycoprotein. Successful incorporation allows them to fluorescently label the carbohydrates through bioorthogonal chemical ligation, which avoids disturbing the native biochemical reaction of a cell.

This helps them to visualise the interactions inside a living cell. Ultimately, the fine-tuning of the glycosylation pathway modifies a protein’s function without changing the underlying amino acid sequence.

THE IMPORTANCE OF GLYCANS Glycans are involved in many processes that are vital to eukaryotic cell functioning, including quality control, protein transport, immune and developmental responses.

For example, N-linked glycans (which are glycans attached to asparagine side chain nitrogen) play an important role in the cancerous cell recognition process. This makes them a potential target in cancer therapeutics. In addition, glycoproteins of viruses such as the human immunodeficiency virus (HIV) contain various N-glycosylation sites, which may aid in shielding the virus from immune system recognition. Removal and modification of such glycans helps to understand viral functioning and develop suitable treatments.

ON TO BETTER GLYCOPROTEIN DETECTION METHODS The need to visualise protein glycosylation

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Chemistry

within living cells has driven the development of metabolic glycoengineering over the past two decades. Professor Wittmann has spent much of his career dedicated to detecting glycoproteins. The initial detection methods, such as Staudinger ligation and azide-alkyne cycloadditions, are limited, in some cases even cytotoxic (toxic to cells), and do not allow for independent labelling of two different carbohydrate residues. The inverse-electron-demand Diels-Alder (DAinv) reaction introduced to bioconjugation in 2008 has been shown to be a more suitable bioorthogonal ligation reaction – it can occur inside the body without disrupting existing biochemical processes and in parallel to azide-alkyne cycloaddition.

INVERSE-ELECTRON-DEMAND DIELSALDER REACTION During initial trials using the DAinv reaction, Professor Wittmann synthesised monosaccharides and found that terminal alkenes could be successfully metabolised and thus fused into glycoconjugates for subsequent labelling. Recently, Professor Wittmann examined protein-specific glycosylation of the intracellular proteins OGT, Foxo1, p53, and Akt1 in living cells. The DAinv approach provides several advantages. Reactions cannot only be performed in aqueous solutions but also without addition of toxic catalysts. In addition, the reaction is irreversible. DAinv has also been demonstrated to facilitate the transport of substances to target cells acting as a therapeutic carrier.

Termed click chemistry, such approaches involve synthesising drug-like molecules, which could potentially aid in discovering new drugs. Professor Wittmann has been part of experimental research showing that metabolic oligosaccharide engineering has been successfully employed to implement functional groups amenable to bioorthogonal labelling (‘click groups’) into the extracellular matrix of human dermal fibroblasts. This method also has potential for medical implant ingrowth.

MONITORING INTERACTIONS WITH CARBOHYDRATE MICROARRAYS Carbohydrate microarrays have presented as a suitable tool to monitor interactions between carbohydrates and proteins.

Microarrays have distinct advantages, which include multivalent binding to examine cell–cell interactions. In addition, only small amounts of ligands are necessary to facilitate

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a binding reaction. Experiments that aim to detect pathogens by use of carbohydrate microarrays further allow researchers to collect and examine such pathogens for additional analysis.

MULTIVALENCY AS A NOVEL METHOD TO EXAMINE IMMUNE SYSTEM PROCESSES For a long time, the Wittmann Group has also been examining multivalency in biological recognition. Multivalency enables strong bonds by employing multiple weak binding sites of low-affinity ligands. This concept has been shown to be of importance in carbohydrate–lectin interactions and it further enhances binding specificity. Even small changes of ligand structure can have dramatic consequences on their ability to bind and the efficiency of this process. The development of multivalent carbohydrates further helps to understand how high-affinity lectin ligands may aid in the diagnosis of inflammatory disease processes, pathogen recognition, and the

modification of immune processes. A variety of interactions are now known to take place between multivalent ligands and receptors.

Though multivalency approaches are gaining acceptability among researchers, in terms of their potential within therapeutic and diagnostic applications, the underlying mechanisms of how affinity is increased are not well understood. Indeed, additional insights into the structural aspects of such interactions are required, alongside innovative developments to further examine the multivalent interaction structure.

The Wittmann group has utilised X-ray crystallography and EPR spectroscopy to gain a better mechanistic understanding of protein–ligand interactions. Though structural information of ligand-receptor complexes is rare, the researchers managed to unravel the structure of a ligand multiply bound to wheat germ agglutinin. The result provided the basis for the development of a new type of multivalent ligands currently under investigation.

Recently, the Wittmann group achieved imaging of protein-specific glycosylation within living cells using the inverse-electron-demand DielsAlder reaction www.researchfeatures.com

Detail What sparked your interest in metabolic glycoengineering?

When I first read about bioorthogonal chemistry, I was fascinated by the possibility of carrying out chemical reactions in living systems. These reactions are a good example of the fact that chemistry does not necessarily stand for harsh conditions as is often the perception by the public. Metabolic glycoengineering provides the opportunity for a true interdisciplinary collaboration between chemists and biologists and a way of using chemistry to answer biological questions.

How versatile is this approach? Which other areas of research or medical investigation could it be applied to?

Metabolic glycoengineering offers a number of applications in diagnosis, therapeutic treatment, and basic science.

Many diseases are associated with changes in the glycosylation pattern on the cell surface. In cancerous tissues, for example, sialic acid levels are increased.

This could be exploited to visualise such tissues by metabolic glycoengineering.

In addition, the approach can be used to direct drugs to such tissue areas, allowing a selective treatment (drug targeting). In basic science, the approach has great value to study the impact of the glycosylation of specific proteins of interest on their biological function.

What are the next steps for your research?

We are constantly working on the development of new chemistries enabling improved bioorthogonal ligations reactions. This includes the search for smaller probes that react even faster than the established ones and their application to diverse biological systems (cells, zebrafish, and nematodes). The field provides a playground for talented and creative researchers, and I have many of them in my wonderful group of co-workers. Currently, we apply metabolic glycoengineering to investigate the role of protein glycosylation in proteostasis (the entirety of processes that control the activity of cellular proteins). This research

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is carried out within our collaborative research centre SFB 969 which is just one example of the close collaboration between our Chemistry and Biology Departments fostered by the University of Konstanz.

Which future predictions could you make about metabolic glycoengineering?

Carbohydrates are found everywhere, and the majority of all proteins are glycosylated. Nevertheless, the glycans are often neglected in protein research. I expect that metabolic glycoengineering will have a huge impact on glycobiology.

It will not only help to identify, enrich, and isolate glycoproteins but will also be a tool to change properties of proteins or cells in a desired manner.

Since different glycosyltransferases have different substrate specificities, it might be possible to learn more about the function of specific glycosyltransferases.

The technique is also suited to introduce chemical functionalities in the components of the extracellular matrix with implications for biomaterial science, including tissue engineering.

What are the prerequisites to carry out research at the chemistry–biology interface?

In an ideal case you need an education in both chemistry and biology. Therefore, we started the study programme ‘Life Science’ in Konstanz 15 years ago.

This programme, which is jointly offered by the two departments (Chemistry and Biology), provides training in both disciplines and was the foundation of a very successful cooperation of the departments leading to the joint collaborative research centre SFB 969 funded by the Deutsche Forschungsgemeinschaft (DFG) and the Konstanz Research School Chemical Biology (KoRS-CB) funded within the excellence initiative. Nowadays it is very common that researchers from one department go over to the other department, being in the same building, to discuss current research.

RESEARCH OBJECTIVES Professor Wittmann’s research focuses on elucidating the biological functions of carbohydrates. He has carried out a whole host of research into metabolic glycoengineering over the years, and is also especially interested in the investigation of multivalent carbohydrate–protein interactions and RNA-targeting antibiotics.

FUNDING Deutsche Forschungsgemeinschaft (DFG) Ministerium für Wissenschaft, Forschung und Kunst Baden-Württemberg COLLABORATORS University of Konstanz: • Prof Andreas Zumbusch • Prof Thomas U Mayer • Prof Andreas Marx • Prof Malte Drescher Fraunhofer Institute Stuttgart: • Prof Petra Kluger University of Bonn: • Prof Günter Mayer University of Freiburg: • Prof Maja Köhn BIO Professor Wittmann received his PhD from the Technical University of Munich before carrying out postdoctoral research at the Goethe University of Frankfurt and The Scripps Research Institute in La Jolla, California. Since 2003, he has been professor of organic/ bioorganic chemistry at the University of Konstanz, and in 2016 became the head of the Department of Chemistry and the vice coordinator of the Collaborative Research Center SFB 969.

CONTACT Prof Valentin Wittmann University of Konstanz Department of Chemistry Universitätsstr. 10 78457 Konstanz Germany E: Valentin.Wittmann@uni-konstanz.de T: +49 (7531) 88-4572 W: www.valentin-wittmann.de

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Robotics; Ultrasound

Robots take ultrasound to the fourth dimension The continual search for more and more applications of machines and robots in medicine is intensifying as technology advances rapidly. Sophisticated robots are capable of movements similar to, or even exceeding, the suppleness and sensitivity of a human arm. Ultrasonic imaging techniques have also evolved greatly in the last decade. Professor Floris Ernst and his collaborators at the University of Lübeck research methods to combine the mechanical capabilities of robots with novel ultrasonic imaging and computing power to create automated medical systems.

P

rofessor Floris Ernst is a professor for Medical Robotics at the Institute for Robotics and Cognitive Systems at the University of Lübeck, Germany. The institute is a leader in German research on robotic medical navigation systems. Professor Ernst’s latest project is looking to take novel 3D ultrasound-imaging technology to the next level, developing a robot that can be used for automated ultrasound; for example to monitor a tumour which is being irradiated at the same time by another robot.

TISSUE IN MOTION Our soft tissues, such as our bowels or lungs, constantly move around slightly due to their physiological function and position in our body. Some motions are predictable, such as breathing, while others are not, such as spontaneous bowel movements. This often poses a problem whenever a doctor wants to examine these areas using imaging methods.

Our breathing motions can be both a hindrance and a help during medical exams.

Our lungs, rib cage and any other tissue in their vicinity move due to respiration.

In addition, our ribs block imaging rays, concealing what lies underneath. Here, directed breathing can be an advantage because it moves the ribs out of the way. This is useful for relatively simple examinations.

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In tumour treatment, tissue motion is accounted for by safety margins, i.e., healthy tissue surrounding the tumour that is included in any treatment. The more the tissue area moves, the larger the margin has to be. This creates an increased risk of overdosing more healthy tissue with radiation than necessary.

LOCALISATION WITH X-RAY One common method to localise a target region is the use of artificial landmarks, such as gold markers, instead of visualising the target directly. By finding such markers with X-ray imaging and knowing their position in relation to the target region, the examiner can infer the location of the target in the body. However, the soft tissue in the abdomen has poor X-ray contrast, further complicating the analysis.

Because X-ray examinations can only be performed infrequently, surrogate measurements, such as chest movement, are used to estimate the position of the target.

Any inaccuracy may cause treatment errors.

There are other imaging techniques, but generally current methods are too slow to track intracorporeal organ motion adequately.

ULTRASOUND AS AN EMERGING ALTERNATIVE Two-dimensional ultrasound (US) is one of the most common imaging techniques used

in routine diagnostics. It does not depend on harmful radiation, which means that a patient can be exposed to US repeatedly and for longer periods. However, using US requires a significant amount of training and the quality of results depends greatly on the skill of the physician. The examiner uses marker points to navigate through the body. Because organs are scanned in layers, it is often unclear which section of an organ is being displayed. Trying to establish a diagnosis retrospectively using

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The 4D ultrasound technology in action using a dummy for testing.

saved images is nearly impossible without knowing the marker points, scanning angle and other details.

Nevertheless, US devices are fairly compact and cheaper than alternative technologies, such as computed tomography or magnetic resonance imaging. Real-time images are created quickly but are generally less detailed than tomographic results and may be flawed due to technological artefacts.

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The recent emergence of three-dimensional US has solved some problems by eliminating the restriction to 2D layers. The target, along with surrounding tissue, can now be imaged at the same time. Where required, layer views can be derived from recorded data.

ENTERING THE FOURTH DIMENSION Now that creating 3D US images in real-time (i.e., 4D US imaging) is possible, the next step is to eliminate manual positioning of the scanner because data from such moving

Professor Ernst is developing an ultrasound robot that can monitor a tumour during irradiation 37

Robotics; Ultrasound

The 4D ultrasound technology in action using a dummy for testing.

images are impractical for retrospective analysis. This is where robotic arms enter the stage. Ideally, these detect the target region automatically and adjust to tissue movements by quickly processing 3D images whilst also maintaining a high image quality. Effectively, this creates motionless tissue representations on screen.

There are only very few robotic real-time imaging devices available to date, none are used commercially. An ideal field of application would be radiation therapy. There, the two main approaches for image-guided tumour treatment are based on tracking or gating. Tumour tracking involves adjustment of the treatment beam through movement of the beam source or the treatment couch, or by adjusting the beam geometry and can be used for all moving tumours. Gating, however, is only used for tumours liable to move with respiration. In this approach, treatment is only applied during defined breathing episodes, i.e., end expiration. This can be improved by using a technology called deep inspiration breath hold, which prolongs the overall treatment time.

None of the emerging technologies for USdirected robotic arm positioning integrate radiation therapy yet. Professor Ernst’s team and collaborators are working on this specific application. Success would be highly beneficial because no US specialist can be near the patient during ongoing irradiation for safety reasons.

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Since a robot can work by itself, this will allow hospitals to make better use of specialist personnel’s time. Eventually, 4D US robots could even be used to assist in automated surgery A major technical challenge in Professor Ernst’s endeavour is the blocking of therapeutic beams by the US device.

Unsurprisingly, the position for the US device that yields the best images is, quite often, also the best position for the treatment device. One idea to compensate for this flaw is to develop treatment plans which ensure that all robotic arm movements are used as effectively as possible. Another idea is to design devices that allow X-rays to pass through them unhindered.

A GLIMPSE INTO THE FUTURE 4D technology could be used in routine and follow-up diagnostics to calculate patient coordinates and allow image comparison over time. When mounted on a robot, it would be the first long-term imaging modality available for clinical use. It could help create virtual organs from 3D data for analysis. A long-term ambition for Professor Ernst and his team is the development of diagnostic algorithms from standardised data packages to improve the quantification

of exam results. These applications may alleviate pressures associated with the lack of physicians in remote areas.

Since a robot can work autonomously, the examiner would be able to leave the patient during lengthy examinations. This would allow hospitals to make better use of specialist personnel’s time. Eventually, 4D US robots could even be used to assist in automated surgery.

The advances from 2D to 4D US imaging have been significant thanks to Professor Ernst and other researchers in this crossdisciplinary field. The next level is to now further improve and broaden medical applications. Such investments will not only advance patient care, but also be compensated through savings in staff and treatment time. Considering that funding for public health services is more valued than ever, such innovative developments should be embraced.

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Detail Could 3D ultrasound completely replace X-ray scans in the future?

Even though 3D ultrasound is an exciting imaging methodology, it will never completely replace X-ray scans. There will always be situations where X-ray imaging is necessary. These will, for example, be imaging of structures behind bones or the bones themselves, such as cranial or dental imaging as well as imaging of fractures in adults. Additionally, boundaries, where the sonic properties (speed of sound, transmission, etc.) change strongly, will always be challenging for ultrasound. A typical case here is the tissue–air boundary: it’s hard to see inside or through the lungs using ultrasound, and this will not change much in the foreseeable future. Another technology which cannot work without X-ray imaging is computed tomography, and I am convinced that we will continue to use it in the future.

Are there any known side-effects of US? Ultrasound has been in clinical use since the late 1950s, and there is no evidence that it is in any way harmful to the patient. Multiple studies have been performed to determine a possible influence of ultrasound on pregnant women and other patient cohorts, but no clinically relevant data was found.

Nevertheless, it is still common practice to use the lowest possible intensity setting, following the ALARA-principle known from radiology (as low as reasonably achievable).

What other possible applications do you see for robotic ultrasound?

While our main research is focused on ultrasound for radiation therapy, we are also pursuing other ideas. I imagine that 4D ultrasound could become the first medium- to long-term imaging modality available. It is conceivable that we could visualise drug uptake or metabolic changes due to medication. Using the robotic ultrasound device we’re developing, it will also be possible to do long-term US – like

we can today do long-term ECG and 24h-monitoring of blood pressure. Another idea we’re pursuing is the use of ultrasound in the diagnosis of children’s arm fractures, which is currently done using X-ray imaging.

If all goes well, how soon could a robot performing 4D US tracking in radiation therapy become commercially available?

I believe that the technology is nearly there – our progress is very promising, and we have come very close indeed to building a fully functional clinical prototype. If our current research projects continue as planned, we could see a working device by 2020. This will be research only, however, and I estimate that it will take another four to six years to make it commercially available.

Will this new technology require a substantial shift in the required skill set and training of physicians?

Our robotic system can be used in nearly the same way as a regular hand-held ultrasonic probe. The robot is sufficiently supple and force-sensitive to allow unimpeded manual motion of the probe.

The only thing to bear in mind is that the reach of the robot is limited, but experiments have shown that people adapt very quickly.

Do you think patients will be put off or even scared by the lack of human interaction during robotic examination and treatment?

Of course, an automated system may seem scary at first. One of our goals, however, is to make the device as safe as possible.

Under no circumstances will the robot apply excessive forces to the patient – that’s precluded by the manufacturer’s safety settings. Furthermore, we have implemented a technology that will always allow manual intervention, i.e., the patient will always be able to push the robot away should something unexpected or scary happen.

Our progress is very promising, and we have come very close to building a fully functional clinical prototype www.researchfeatures.com

RESEARCH OBJECTIVES Professor Floris Ernst’s research investigates the potential for using robots and novel 3D-imaging technology to carry out ultrasounds within the soft tissue of the human body.

FUNDING • University of Lübeck • German Research Foundation (DFG) ER 817/1-1 • Business Development and Technology Transfer Corporation of SchleswigHolstein (WTSH) 123 16 014 • German Federal Ministry for Economics (BMWi) ZF4109402BZ6 COLLABORATORS Germany: Prof. Alexander Schlaefer, Technical University of Hamburg-Harburg; Prof. Dirk Rades, University Hospital Schleswig-Holstein; Boll Automation GmbH; Saphir Radiochirurgie Zentrum Norddeutschland Switzerland: Varian Medical Systems Imaging Laboratory GmbH Denmark: Per Poulsen, Aarhus University Australia: Paul Keall, The University of Sydney BIO Professor Ernst completed his PhD at the University of Lübeck, investigating motion prediction and correlation algorithms for use in robotic radiosurgery. Following this, he worked as a software engineer at an engineering consultancy before returning to the Institute of Robotics and Cognitive Systems at the University of Lübeck in 2013, where he was appointed Professor for Medical Robotics in 2017.

CONTACT Professor Dr Floris Ernst, PGDipSci University of Lübeck Institute for Robotics and Cognitive Systems Ratzeburger Allee 160 23562 Lübeck Germany T: +49 451 3101 5208 E: ernst@rob.uni-luebeck.de W: www.rob.uni-luebeck.de /florisernst

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A clear vision: using hydrogels to improve cataract surgery outcomes

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Materials

Dr Tina Sabel and her team in the ‘Nanopatterned Biomaterials’ group at Technische Universität Berlin focus their research efforts on novel photosensitive materials. These materials have multiple possible applications but Dr Sabel’s current research has the potential to assist millions of people suffering from cataract.

C

ataract is the predominant cause of vision loss in people over 40 years old. Typically associated with ageing, the lens of the eye becomes cloudy leading to a loss of acuity of vision.

A normal healthy eye has a lens that consists mostly of water and proteins that are arranged to keep the lens clear and functional – all light can pass through the pupil and reach the optical nerve. However, as people age, portions of the proteins in the lens congregate and clump together, thus triggering the formation of a cloudlike condition over a small area of the lens. This opacity eventually spreads to adjacent fibre cells and results in a slow but profound deterioration of the individual’s vision. Treatment usually involves surgery, especially in cases where vision has been seriously compromised; the clouded lens is removed and is replaced by an intraocular lens.

THE ROLE OF INTRAOCULAR LENSES Intraocular lenses (IOLs) are artificial lenses that are typically used to replace a cloudy lens following cataract surgery.

When the natural lens is removed, the eye’s ability to focus is lost and the IOL replaces the lens, restoring vision. The first series of successful IOLs were made of polymethylmethacrylate (PMMA) – a very commonly used thermoplastic polymer – owing to its high transparency and biocompatibility with human tissue (it was not attacked and rejected by the immune system). Early versions of IOLs were not as flexible as a biological lens meaning that, while they improved vision, they did not restore it to pre-cataract acuity. The latest technological advancements, however,

have allowed IOLs to become far more pliable, stable and compatible within their biological environment, and thus solve a variety of visual problems.

CHALLENGES OF IOLS Since the beginning of the 1980s, folded IOLs made from silicone have been used because they allow minimally invasive surgery. However, these folded IOLs were subject to a gradual loss of accommodation (the process by which the eye adapts its optical power to focus on subjects at various distances) and so multifocal IOLs were introduced in the beginning of the 1990s. Yet, these novel biomaterials did not manage to limit the degree of induced photic phenomena such as ‘halos’ or glare around observed objects. Even the latest generation of IOLs that exhibit reduced photic phenomena and consist of ultraflat, bifocal IOLs with diffractive–refractive optics still exhibit persistent problems such as post-operative calcification and secondary cataract. Innovative research is needed in order to overcome such problems and introduce IOLs that have enhanced functionality and give patients a greater degree of freedom.

A NOVEL APPROACH It comes as no surprise that there is still plenty of room for improvement and one area that is particularly promising is the development of IOLs that can operate by means of ‘function by structure’. This means IOLs made of novel biomaterials whose structure can be custom designed in order to fit the optical and mechanical challenges in terms of their respective surface and volume properties. In other words, if we could allow for the transfer of optical functionality (e.g., the ability to give visual

The functionality of the 3D patterned hydrogel implant has the capacity to come as close as possible to the desired functionality of the young natural eye lens www.researchfeatures.com

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Materials

acuity) into the IOL volume, this would give greater freedom in the design of the geometric shape (e.g., to allow for easier insertion) and the option to separately use the surface in terms of a specific interaction with the biological environment (e.g., to ensure it is long-lasting and elicits no immune response). This is where Dr Sabel’s work unfolds its novel approach.

With a background in Physics, but working in the Chemistry department, Dr Sabel’s research focuses on photosensitive polymers for holographic and photolithographic applications, specifically, the implementation of three-dimensional patterned hydrogels for IOLs. Using these new materials could overcome the limitations of existing IOLs such as the long-term preservation and/or restoration of accommodation.

Such photosensitive biomaterials can be optically patterned by means of photoinduced crosslinking and by means of volume holographic structuration – where a pattern is recorded inside a volume of light-sensitive material and the consequent hologram is reconstructed by one of the recording waves. This process allows for optical structuration in three dimensions through the entire volume of a photosensitive material, thus allowing for three-dimensional optical structure within the bulk (by means of diffraction) and two-dimensional topographic patterns on the surface (interaction with the biological environment).

ADVANTAGES OF SUCH AN APPROACH There are profound advantages when using such materials for IOLs, especially when it comes to clinical situations. 3D patterned hydrogels allow for high optical image

quality, significantly decreased photic phenomena and high mechanical flexibility.

However, and most importantly, the functionality of the implant has the capacity to come as close as possible to the desired functionality of the young natural eye lens.

Furthermore, such a novel approach has the capacity to effectively prevent issues such as the opacification and calcification of the IOL, based on the transfer of optical functionality from the surface into the volume of the IOL implant.

Looking to the future, Dr Sabel’s investigations regarding the integration of 3D patterned hydrogels for intraocular, function-enhanced lenses have the capacity to offer custom-based solutions to patients undergoing cataract surgery by exploiting the properties of photoresponsive polymers, volume holographic techniques and multifunctional biomaterials.

Cataract is the predominant cause of vision loss in people over 40 years old

Types of photopsias Point source of light

Glare

Halo

Starburst

Top image illustrates the principle of uv-curable polymer for 3D optical patterning.

Bottom image shows the three different types of photopsia or light distortion.

Left image is an example of an intraocular lens implant. Frank C. Müller [CC BY-SA 3.0 (http:// creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

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Detail What is your motivation behind working in such a well-examined field?

My motivation is to look at things with fresh eyes and without prejudice.

It is exciting to work in such an interdisciplinary field and on a project that requires basic research while at the same time having such a concrete application for the benefit of many people. It is also quite a challenge to merge several well-examined fields for the opening up of this novel application for volume holography.

What exactly is volume holography and how does it work?

In general, volume holography allows us to store and restore complex information in a purely optical way. More specifically, a hologram is written into the volume of a photosensitive material by interference laser exposure in the sub-second range.

No development or other post-exposure treatment is needed. The resulting micropattern can also be observed by optical microscopy. Finally, a volume hologram fulfils its function by diffracting light in a pre-defined way. This function can also be to focus light. Therefore, a volume hologram can operate as a lens, while at the same time it is very flat, light and flexible.

Looking to the future: Will 3D patterned hydrogels for intraocular, function-enhanced lenses ultimately substitute the existing lenses used following cataract surgery?

Yes, if the transfer of optical functionality into the IOL volume succeeds, there is a good chance that such novel 3D patterned IOLs will be a convincing

My motivation is to look at things with fresh eyes and without prejudice

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substitute with advantages regarding optical functionality and biocompatibility and maybe also the ability to allow for accommodation.

It could also be crucial that volume holography has the potential to allow for the fabrication of superior performance IOLs with highest precision and low cost.

Can this technique prevent the calcification of the IOL even after 10–20 years?

I believe this is possible. One of the main benefits we expect from the transfer of optical functionality into the IOL volume is the resulting free surface of the IOL implant. We know that the surface topography crucially impacts how cells behave on a certain biomaterial surface. A different surface topography on one and the same material can determine if cells do adhere and spread or if the surface appears to be anti-adhesive.

Against this background, we consider the free surface of an IOL implant as a significant opportunity to improve the interaction with the biological tissue of the eye.

What are your primary targets regarding this novel technique in the next five years? E.g., designing prototypes, etc.

The first goal is to compose and optimise the hydrogel mixture for the 3D optical structuring. Therefore, it is necessary to investigate the impact of individual components on the complex process of 3D optical patterning. Secondly, we are curious to study the cellular response on the 3D and surface patterns, respectively, in order to estimate the interaction with biological tissue. Based on those basic investigations we are indeed working towards a real application, including the design of prototypes.

RESEARCH OBJECTIVES Dr Sabel’s team in the department of chemistry in Technische Universität Berlin, is currently performing pioneering research in the field of novel materials that can be used to create intraocular lenses.

FUNDING This project is supported by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under grant number SA 2990/1-1.

COLLABORATORS • Prof Dr Marga C. Lensen, Nanopatterned Biomaterials, Technische Universität Berlin • Fakulty II, Institute of Chemistry BIO Dr Tina Sabel is a postdoc in the group ‘Nanopatterned Biomaterials’, in the Department of Chemistry at the Technical University of Berlin, where she graduated with Dr. rer. nat./PhD in Physics 2014. Her research interests are photoresponsive polymers, 3D optical diffractive structures, volume holographic techniques and multifunctional biomaterials.

CONTACT Dr Tina Sabel Technical University of Berlin, Faculty II Institute of Chemistry Nanostructured Biomaterials Sekr. TC1 Room TC 019 Strasse des 17. Juni 124 10623 Berlin Germany T: +49 30 314 29555 E: tina@physik.tu-berlin.de W: http://lensenlab.wixsite.com/ lensenlab/post-doctoral-crew www.researchgate.net/profile/Tina_ Sabel/contributions

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Using statistical modelling to understand cell heterogeneity

Computational Biology

Dr Christiane Fuchs is the Group Leader of the Biostatistics Group at the Institute of Computational Biology at the Helmholtz Zentrum München, German Research Center for Environmental Health. Her research applies statistical modelling to the analysis of biological data, including her latest work investigating the evolution of acute myeloid leukaemia from collaborative data.

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cute myeloid leukaemia (AML) can result from myelodysplastic syndrome (MDS) – a disorder that affects the number of healthy blood cells a person has. Rather than generating fully functional blood cells, the bone marrow of people with MDS produces underdeveloped or malformed blood cells, which cannot transport oxygen around the body as effectively. This disruption of the maturation of stem cells into specific, ‘differentiated’ cells, leads to high levels of immature white blood cells known as blast cells. When the level of these cells in the blood rises to a certain point, it starts to impact the function of other blood cells, causing AML. Using statistical analysis and models, Dr Fuchs and her collaborators are examining the variation and heterogeneities in whole populations of cells that can become cancerous and cause AML, determining how these evolve over time. Dr Fuchs’ work is made possible through the Collaborative Research Centre 1243, a collaboration of clinicians, molecular biologists, population geneticists, computational and evolutionary biologists funded by the German Research Association (DFG). The centre takes an interdisciplinary approach to investigating the varied aspects of cancer evolution. By drawing together scientists from disparate fields, the centre aims to better understand the evolution of tumours in order to improve diagnostics, prognostics and treatments for cancer patients.

UNDERSTANDING HETEROGENEITY To understand how cells develop into

cancer cells, we must first understand the differences, or heterogeneities, between how cells (of the same or different types) express our underlying genetic code. In healthy individuals, the DNA is the same throughout the whole body, but cells behave differently depending on which genes are active and how active they are: cells are heterogeneous. Subtle differences in gene expression can cause proteins that are vital to cell function to be produced differently.

Sometimes these differences within otherwise identical cell types originate from cancerous development, such as with AML, and this is the area that Dr Fuchs and her team are interested in.

In order to examine gene expression, scientists use RNA, the chemical that ‘translates’ our DNA during normal cell replication. Heterogeneity in gene expression can be identified from gene expression measurements using statistical methods. Some techniques of examining cell properties rely on profiling large numbers of cells in a sample and calculating an average genetic expression profile. But, in the case of diseases like AML, where rare cell types and the differences between individual cells are important, this type of bulk technique is less useful. It is more helpful to look at single cells because being able to identify these rare cell types is essential to understanding the problems they cause.

Data from single cells, on the other hand, is affected by the way you extract information by sequencing the cells (i.e., reverse transcription or RNA sequencing): The data will contain ‘noise’ dependent on the extremely complex methods used. As a

Using statistical analysis and models, Dr Fuchs and her collaborators are trying to discern the hierarchy of processes that lead to the development of abnormal sub-clones that can cause acute myeloid leukaemia 45

Computational Biology

consequence, it is unknown whether observed variation is the same as the real variation being present in the body or just an artefact of isolating and handling the cells. Hence, small, subtle effects can be hidden in single cell data.

STATISTICS TO THE RESCUE Statistical methods can provide the solution to this problem. Dr Fuchs and her team have developed statistical techniques to analyse the data generated by a method called stochastic profiling to measure the way that RNA molecules are expressed from a patient’s genes.

Stochastic profiling, which is somewhere between a population-scale and single-cell sampling method, was originally developed as an experimental technique by her collaborator Dr Kevin Janes at the University of Virginia. The method works by randomly collecting many ten-cell subsamples rather than individual cells, which minimises the effect of background factors because there is ten times more cell data. Information about single-cell properties is then extracted with a mathematical model.

Dr Fuchs built her model on basic mechanisms of gene expression and combined various types of statistical models (e.g., log-normal and exponential distribution models) to reflect various characteristics of gene expression. By fitting the model to data, Dr Fuchs and her team were finally able to parameterise heterogeneities in gene expression.

VALIDATING THE MODEL The team validated the model using theoretical and experimental data – first by simulating the expression and regulation of ten-cell samples with known distributions, then by comparing the statistical results to experimental data.

In order to fully validate Dr Fuchs’ findings, the method needed to be applied to real gene expression data. This was provided

Tumour cells under a microscope

by Dr Kevin Janes and his PhD student (now postdoctoral fellow) Sameer Bajikar – using fluorescent labels, they were able to create images in which they could count the number of cells in a tissue (because the nuclei were visible) and highly expressed regions of the gene of interest. From these images, they could experimentally estimate the frequency of two cell populations, those with high expression rates and those with low expression rates of the gene. The agreement between this experimental estimate and Dr Fuchs’ statistical estimate was surprisingly

Dr Fuchs and her team have developed a statistical method called stochastic profiling analysis, which can help understand the way that RNA molecules are expressed from a patient’s genes 46

good, providing concrete confirmation that Dr Fuchs’ method works. However, while the experimental measurement took weeks or months to confirm, a computer can complete the complex calculations required by Dr Fuchs’ method in a matter of minutes, or even seconds.

Dr Fuchs and her team compared their method with the analysis of comparable amounts of single cell data. They found that the estimates of expression frequency obtained using their model were considerably more accurate than with other models, when considering rare or very rare clusters of cells that are typical in individuals with cancers and other diseases.

IMPROVING ON EXISTING TECHNIQUES The method developed by Dr Fuchs and her team represents an improvement on singlecell profiling, which creates considerable technical noise because of the sampling methods used, and on bulk methods, which cannot identify specific heterogeneities that might be responsible for causing

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Detail How did your work on stochastic profiling lead on to your current work?

Transcriptional heterogeneity is an essential factor which must be considered in various contexts, not only in disease progression like cancer, but also in e.g., developmental processes. In our initial work, we developed statistical methods and validated them on experimental data.

In the current project, we are driven by biomedical questions to dissect cell-tocell heterogeneities in AML patients.

How do you find the most suitable models to fit the data?

As a statistician, I start by looking at the data-generating process, i.e., what is known about the underlying biological processes, and from these derive appropriate probability distributions.

Models should at the same time be designed as simply as possible and as complex as necessary. Moreover, as the biology of life is not exactly predictable, I incorporate random components in my models.

How novel is the field?

Measuring transcriptional expression from single cells or small numbers of cells became possible only a few years ago. Experimental methods as well as computational resources develop rapidly, enabling new routes to understand genetic mechanisms. In its current form, stochastic profiling analysis would not have been possible 20 years ago.

What other applications have you found for your method?

Our initial investigations focused on

disease. It is a reproducible, quantitative and computationally efficient way of profiling cells that generates more reliable information than single-cell methods, without the associated complexities and issues of singlecell profiling.

It is as yet unclear how powerful the method is with a small sample of ten-cell averages without the possibility to enlarge the dataset by merging co-expressed genes.

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Every dataset is different, and every application entails new challenges human cells, but in the meantime we realised that stochastic profiling can also become powerful in microbiology. Here, understanding cellular heterogeneity might help gain insights, for example, into the composition of the microbiome or the formation of antibiotic resistance, but single-cell analysis is experimentally even more difficult because the genetic material is much sparser than in human cells.

What further developments do you plan to improve the method?

Every dataset is different, and every application entails new challenges. Stochastic profiling analysis is a general concept, but it needs to be adapted to emerging technologies like novel sequencing methods and to other molecular subsets beyond the transcriptome, e.g., the epigenome. It also needs to be tailored towards different organisms, such as bacteria or viruses which have different genetic material to mammalian cells. With these extensions, we want to make stochastic profiling analysis an even more powerful tool for understanding cell-to-cell heterogeneity and ultimately gain more insight into developmental processes and cellular changes within disease progression.

RESEARCH OBJECTIVES Dr Fuchs’ research looks at statistical modelling and inference with applications in genetics and molecular biology. Within this field, she is particularly interested in the theory and application of stochastic differential equations.

FUNDING German Research Association (Deutsche Forschungsgemeinschaft, DFG): Collaborative Research Centre 1243 “Cancer Evolution”, Subproject A17 COLLABORATORS • Prof Fabian Theis • Dr Carsten Marr • Prof Kevin Janes • Dr Sameer Bajikar BIO Dr Fuchs is a mathematician with a doctorate in Statistics, having received an MSc degree in Computational Mathematics and a Diploma in Mathematics beforehand. Following her PhD, she joined the Helmholtz Zentrum München as a postdoctoral researcher.

Since 2013, she has been leading the Biostatistics Group at the Institute of Computational Biology.

CONTACT Dr Christiane Fuchs Helmholtz Zentrum München German Research Center for Environmental Health (GmbH) Institute of Computational Biology Ingolstaedter Landstr. 1 85764 Neuherberg Germany T: +49 89 3187 3385 E: christiane.fuchs@helmholtz-muenchen. de

What is clear though, is that for clusters of such genes, which are implicated in certain diseases like breast cancer or leukaemia, the technique performs very well.

The next step will be for Dr Fuchs and her team to apply the model to data supplied from collaborators at the CRC and to identify cell-to-cell variation in gene expression in the context of cancers like AML.

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Thought Leadership

DESY - opening new windows onto the universe Unlocking the mysteries of the universe is all in a day’s work for scientists at Deutsches Elektronen-Synchrotron (DESY) in Germany. Using the centre’s powerful particle accelerators, they are able to probe into the secrets of exploding stars, black holes, the big bang and more. DESY’s accelerators are also sources of intense electromagnetic radiation, which are used to perform pioneering investigations in the fields of physics, chemistry, geology, biology and medicine. We caught up with Professor Dr Helmut Dosch, DESY’s Chairman of the Board, to find out what makes DESY the world’s leading centre for X-ray experiments.

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orget looking for a needle in a haystack, scientists at Deutsches Elektronen-Synchrotron (DESY) are looking for the tiniest building blocks of matter in the world.

Based in Germany, DESY is an internationally leading accelerator centre, which houses the world’s most intense X-ray source and particle accelerators that have achieved record speeds. These facilities enable the exploration of the microcosm, in all its infinite variety. Scientists can look at everything from the interactions of minuscule elementary particles and the behaviour of new types of nanomaterials, to biomolecular processes that are essential to life.

up tiny, electrically charged particles nearly to the speed of light – that is, to almost 300 000 kilometres per second. A broad range of scientific disciplines benefit from these fast particles. Particle physicists bring them together in head-on collisions to investigate the tiniest building blocks of matter. Chemists, materials scientists and biologists use accelerators to generate the brightest X-ray radiation in the world in order to examine diverse materials ranging from aircraft turbines to microchip semiconductors and proteins that are essential to life. Medical researchers use accelerators for cancer therapy, as the high-energy particle beams can be targeted to destroy tumours.

Solid-state physicist Professor Dr Helmut Dosch is DESY’s Chairman of the Board. He met up with Research Features to discuss some of the fascinating research that takes place at DESY and to outline some exciting future developments.

Can you tell me more about DESY’s background and the aims of the centre?

DESY was founded in 1959 as a new lab in the north of Germany to operate a particle accelerator called an electron synchrotron. The great scientific success, the professional operation and subsequent international recognition of this facility led to a rather dynamic development becoming a leading centre for accelerator research and development (R&D) and particle physics. The

Firstly, can you explain what a particle accelerator does?

Particle accelerators are among the most important tools for research. They speed

DESY has always been a driver of new frontiers in science and technology 48

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particle physics legacy of DESY is intimately linked to the development of the storage rings (circular particle accelerators), DORIS, PETRA and HERA. By the 1960s, the lab had pioneered the use of synchrotron radiation for the examination of matter, materials and biological systems.

This quickly grew to a second branch of the lab: science with synchrotron radiation, plus X-ray lasers. This is today the main focus of DESY, which is now the site of the high brilliance storage ring PETRA III, the world´s first free-electron laser FLASH, and the European X-ray laser XFEL. With the reunification of Germany in 1990, DESY once more expanded its size and its research portfolio. A new site was created at Zeuthen, near Berlin, in 1992, to explore astroparticle physics, and which is today on the verge of becoming an international centre in the field.

DESY’s mission encompasses top level user operation of its X-ray facilities and research in photon science, nano-bio sciences, particle/ astrophysics and accelerators R&D. We are creating the knowledge base that is needed in order to solve the huge and urgent challenges that society, science and the economy are facing. The research facilities we develop and operate for this purpose are open to scientists from all over the world.

DESY is member of the Helmholtz Association of German Research Centres.

How big an influence has DESY had on scientific research since it was established in 1959? What achievements really stand out for you?

DESY has always been a driver of new frontiers in science and technology.

Among the many scientific achievements are the discovery of the gluon, the “glue particle” that holds the quarks together and without which there would be no atoms;

In the next few years, we will witness many disruptive scientific achievements in all areas of science 50

the observation of B meson mixing; precise measurements of the structure of the proton; the discovery of the X-ray magnetic dichroism and of the synchrotron Moessbauer scattering. In collaboration with the Max Planck Society, groundbreaking work has been done to decipher the structure of ribosomes, the “protein factories” of living cells. For this, Ada Yonath, who conducted her research at DESY between 1984 and 2002, received the Nobel Prize in Chemistry in 2009. DESY has also been driving cutting edge science with free-electron lasers (FELs). Between 2000 and today, Henry Chapman at DESY pioneered serial femtocrystallography, which is widely considered to be the next quantum leap in structural biology.

DESY has had a seminal influence on the development of theory and of novel accelerator concepts. In 1987, Evgeny Saldin laid down the theoretical basis for free electron X-ray lasers. These devices can not only record the forms of atoms and molecules, but their functions too. At DESY, this revolutionary theoretical idea was first converted into X-ray laser facilities by developing superconducting accelerators which are today the heart of FLASH and the European XFEL.

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Thought Leadership

Particle accelerators at DESY (LINAC II, PIA and DESY II are preaccelerators for the operation of the storage ring PETRA III), together with the two free-electron lasers FLASH and the European XFEL LEFT: The FLASH accelerator tunnel

Can you explain what photon science is?

How did it become one of the main focuses of activity at DESY? Photon science refers to all research disciplines which exploit the high brilliance X-ray radiation from electron accelerators.

These “supermicroscopes” reveal the atomic details and the behaviour of materials and biomolecules – and form the basis for developing new technologies.

Their penetrating power allows access to the intrinsic time scale of the nanoworld, i.e. to the time scale of electronic and molecular motions. This enables researchers for the very first time to observe in real time how chemical bonds form and break, the holy grail in chemistry, catalysis and materials science. The European XFEL, and other similar facilities worldwide, will transform the way we design new materials and drugs.

Examples of photon science include: protein crystallography, X-ray tomography of materials and angular resolved photoelectron spectroscopy of functional materials.

DESY is the brain behind the European XFEL. DESY devised the idea, the concept and technical design and developed the accelerator technology, based on superconducting niobium. DESY is responsible for the heart of the XFEL, the 2km superconducting linear accelerator which brings electrons up to the energy of 17.5 GeV.

DESY pioneered this field in the 1960s, in parallel to its particle physics program. With the shut-down of DESY’s last particle collider HERA, in 2007, and the parallel launch of the construction of the European XFEL, photon science became the main activity at DESY. The European X-ray free electron laser (XFEL) is due to open at DESY later this year. Can you describe what it does and what its value will be to researchers? What is the significance for DESY of having this new research facility based on site?

The European XFEL is the most powerful X-ray source in the world. Its X-rays are used to study the nano world, as they are able to show much finer details than visible light.

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During the last few years, DESY has been building up interdisciplinary research labs on campus, such as the Center for Free Electron Laser Science (CFEL) and the Centre for Structural System Biology (CSSB), which will exploit the unique opportunities presented by the European XFEL. In the next few years, we will witness many disruptive scientific achievements in all areas of science. Clearly, the international reputation of DESY as a world-leading accelerator and photon science lab will further be boosted by the success of the European XFEL.

Can you tell us more about DESY’s connection with the Large Hadron Collider (LHC) in Geneva?

After the shutdown of HERA in 2007, DESY very quickly developed a new enhanced cooperation with CERN. Today, most of the DESY activities in particle physics are focused on the LHC, and DESY is the national hub for the German LHC community. Currently, DESY is building up a detector assembly facility which will be used by all German universities for the construction of essential parts for the next generation of particle detectors at the LHC. At annual DESY-CERN board meetings, DESY synchronizes its particle physics priorities with the CERN directorate. There are also strong personal ties that connect DESY and CERN. For example, both the former Director General of CERN, Rolf Heuer, and the current Director for Research and Computing, Eckhart Elsen, spent a long time at DESY before their appointments at CERN. Can you tell us about some of the exciting research projects currently taking place at DESY? With pleasure, but this can only be a very personal selection and a snapshot of the many scientific breakthroughs coming out of the DESY labs and collaborations. I will highlight a few that show the breadth of science at DESY. Let’s start with astrophysics. Various kinds of particles from the cosmos constantly reach the Earth – particles that can provide insights into the happenings in the depths of the universe.

The DESY researchers in Zeuthen use two of these cosmic messengers, neutrinos and gamma rays, to uncover the secrets of stellar explosions, cosmic particle accelerators like the surroundings of black holes, or of dark matter.

As part of their studies, the researchers are involved in a collaborative project called IceCube, which operates a huge neutrino observatory below the surface of the Antarctic ice cap at the South Pole.

Neutrinos hold the key to some of the most fundamental questions in physics, but they are notoriously difficult to study.

However, their activities are easier to detect in deep ice. IceCube was built to search for high energy neutrinos created in the most extreme cosmic environments, a search that is driven by the wish to understand the origin and nature of cosmic rays. The IceCube observatory has already detected the highest energy neutrinos ever recorded.

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Thought Leadership

Solid-state physicist Professor Dr Helmut Dosch is DESY’s Chairman of the Board

The European XFEL and other similar facilities worldwide will transform the way we design new materials and drugs Now shift your focus from the South Pole to sub-Saharan Africa, where more than 60 million people are threatened by the sleeping sickness parasite, which is transmitted by the bite of the tsetse fly. Using serial femtocrystallography, a technique I mentioned earlier, DESY scientists and their collaborators exposed a possible Achilles' heel of this parasite. Their sophisticated analysis of data taken in experiments with a free-electron laser revealed the blueprint for a molecular plug that can selectively block a vital enzyme of the parasite, thereby rendering it inactive.

Another recent experiment at DESY’s X-ray source PETRA III revealed, with atomic resolution, the structure of a key enzyme of the Zika virus. This enzyme is essentially the engine that enables the virus to replicate. If this enzyme could now be targeted with the right drug, thus inhibiting the replication, the infection could be stopped.

A more fundamental result was obtained at DESY’s free-electron laser FLASH. Here, scientists found evidence of long elusive helium molecules consisting of three atoms (He3), whose existence was predicted 40 years ago by the Russian theoretical physicist Vitaly Efimov. This high-precision measurement of extremely weakly bound states illustrates the potential of FLASH.

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The discovery allows better understanding of metrology (measurement science) at low temperatures.

Last summer, we were given a glimpse of the future, with the first electron beam produced by an innovative accelerator project. This was a collaborative venture, conducted by DESY and the University of Hamburg. The technology used in the experiment, plasmawakefield acceleration, will hopefully one day give rise to particle accelerators that are much smaller and more powerful than the ones we operate today. That is why a lot of effort and resources are devoted to this field of research. The electrons in this first test run were accelerated to energies of around 400 MeV, using a plasma cell of just a few millimetres in lengths. This corresponds very nearly to the energy that is achieved by DESY’s linear pre-accelerator LINAC II – in 70 metres!

Finally, I would like to mention a more applied research project that has already sparked interest in the industry. It is about a new deposition method for custom-made magnetoresistive sensors, which will probably revolutionise the range of applications for magnetic sensors. These tiny, highly sensitive and efficient components are everywhere in our daily lives. In cars, they measure the speed of rotation of the wheels for ABS and

ESP systems. They are also found in mobile phones, they read data from hard drives and contribute to our safety by detecting microscopic cracks in metal components.

This variety of applications requires a very individual tailoring of these sensors for their respective functionality, a tuning that is extremely limited in conventional production methods. DESY scientists have now discovered a method that allows a plethora of new sensor properties to be achieved in a straightforward fashion. Instead of adjusting the application to fit the available sensors, the new technology means that one can customize the sensor to fit the intended application.

What are the key research focuses for the organisation over the next two years?

We will be working on the technical design reports for upgrades of PETRA III and for the free-electron laser FLASH, to ensure DESY’s leading position in photon science in the future.

The start of the user operation of the European XFEL this summer is eagerly anticipated and we are looking forward to the first experiments there, for instance those at the Helmholtz International Beamline (HIB). HIB is a new kind of experimentation station, based at the XFEL, which will be used to conduct experiments under extreme

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Preparation of an experiment at the measuring station P06. The beamline P06 at the brillant X-ray source PETRA III provides advanced visualisation with micro/nanoscopic spatial resolution using different X-ray techniques

How do you see research at DESY changing over the next ten years?

I see several developments in the next years: 1. DESY will upgrade PETRA III into an ultimate storage ring providing coherent X-rays at 0.1 nm wavelength (“PETRA IV project”). This facility will allow novel X-ray imaging possibilities of all materials’ properties, with the highest resolution, which will have a huge impact on the design of advanced materials.

2. DESY´s national and international role in astroparticle physics will strongly increase with the advent of the Cherenkov Telescope Array. DESY will host the CTA International Science and Data Management Center at its site in Zeuthen.

conditions of high pressures, temperatures, or electromagnetic fields. The insights gleaned from these experiments will help improve models of planetary birth, among other things, and will also provide a basis for innovations in materials research and fusion technologies.

Researchers plan to use the ‘’pump and probe’’ technique, where a dynamic process – for example, a chemical reaction – is started with one laser pulse and analysed with another laser pulse after a well-defined delay. Repeating the experiment with slowly increasing delay times provides a series of snapshots that can be arranged like a "molecular movie" flip-book of the reaction or process under investigation.

At the same time, there will be strong efforts to push the limits of accelerator technologies and establish a distributed test facility for laser-plasma acceleration. This technique could revolutionise not only the fields of photon science and particle physics, but also open the route towards innovative medical applications.

Last but not least, the Cherenkov Telescope Array (CTA) will be launched - the world’s largest gamma-ray observatory and one of the cornerstones of astrophysics - at DESY in Zeuthen. Our researchers expect that

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observations made with the CTA observatory will unveil fascinating new phenomena and revolutionise our understanding of fundamental physical processes at the smallest and largest scales in our Universe.

International collaboration is a key element in DESY’s success. What does DESY do to foster collaboration?

As you correctly say, international collaboration has always been and will in future remain a key for DESY’s success. All DESY projects are so demanding that they require the collaboration of the best. In turn, DESY has always been striving to be a meeting and networking place for scientists from all over the world.

This implies an open mind and a culture of diversity, as well as professional structures for hosting scientists from abroad. These include an international office, a dual career centre, English as lingua franca, language and intercultural training courses, plus many other services. DESY´s research infrastructures play a central role, with robust funding which attracts young scientists and leaders in the field to Hamburg. DESY is a coveted partner for international cooperation. Its many strategic partnership agreements with leading research institutions across the world support long-term international cooperation projects.

3. The DESY site in Hamburg is on its way to becoming an International Science Park, with new physics, chemistry and biology labs of the University of Hamburg to be built on campus. This will further boost the interdisciplinary use of DESY’s facilities and attract more young scientists.

4. DESY will become more visibly engaged in the innovation chain and engage in strategic cooperation with industry.

5. DESY accelerator research will develop a strong focus in plasma acceleration technologies, with the aim to prepare a conceptual design report for a new facility fuelled by a plasma accelerator.

Contact Deutsches Elektronen-Synchrotron DESY Ein Forschungszentrum der HelmholtzGemeinschaft Notkestr. 85 D-22607 Hamburg E: desyinfo@desy.de W: www.desy.de

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Using nanostatistics to determine the functions of cells at a molecular level

Statistics

Dr Axel Munk from the University of Göttingen and the Max Planck Institute for Biophysical Chemistry focuses on nanostatistics and the development of methods that allow researchers to analyse data and recover objects from a series of indirect and random measurements. His work is at the cutting edge of statistical inverse problems with potent applications in biophysics, such as the signal extraction of electrophysiological data for understanding protein– membrane interactions, cell and molecular biology, and optical nanoscale microscopy. Moreover, Dr Munk’s work has proved to be of significant assistance to forensics and security by modelling the growth of fingerprints, improving matching for adolescents.

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hat exactly is a statistical inverse problem?

To understand the importance of Dr Munk’s work, we must first answer this question. In principle, the nature of statistical inverse problems revolves around the notion of inverse recovery: I give you the answer, can you tell me the question? Therefore, statistical inverse problems fundamentally involve backward reconstruction such as recovering structures from parts of the body in tomographic scans or protein structures in a compartment of a cell from spectroscopy or optical microscopy. In all these cases, the nature of the initial observations is, however, random by default. Hence, in a statistical inverse problem a random number of letters of the answer are wrong in addition. I give you an incomplete answer, can you still tell me the question? This renders solving these problems as particular difficult and tricky.

STATISTICAL INVERSE PROBLEMS Therefore, it is essential to develop computational, statistical and mathematical methods that have the ability to extract as much information as possible from the initial random data. This therefore requires the causal factors that produced the given set of random observations to be quantified. This is exactly what Dr Munk’s work in the recently founded Felix Bernstein Institute for Mathematical Statistics in the Biosciences at the University of Göttingen

and the Max Planck Institute for Biophysical Chemistry (Germany) has managed to achieve.

FUNCTIONAL PRINCIPLES OF CELLS AT A MOLECULAR LEVEL Molecular biology, biophysics and biomedicine all investigate activities in various systems and compartments of cells down to a molecular scale. Hence, they all study biological macromolecules as a collective result of atomic-resolution structural characterisations and subcellularscale observations. The implementation of a distinct set of computational methods and algorithms can provide researchers with significant information regarding the spatial and temporal distribution of specific molecules within a compartment of a cell. This will, in turn, allow for the precise estimation of the number of molecules present at a given location (where) and at a given time (when). It is here that the nature of statistical inverse problems at the nanoscale (the millionth part of a millimetre) becomes of utmost importance.

STATISTICAL METHODS FOR OPTICAL NANOSCALE MICROSCOPY The development of superresolution fluorescence microscopy has allowed for the substitution of conventional light microscopes that have a very limited resolution. Therefore, superresolution microscopy can visualise the structures and the dynamics of biomolecules down to nanoscale levels with an unprecedented

The nature of statistical inverse problems revolves around the notion of inverse recovery: I give you the answer, can you tell me the question?

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Health

Statistical alignment of a sequence of 35,000 recordings of a beta tubulin network in Hela cells imaged with single marker switching optical nanoscopy. Total recording time is several minutes. During the measurement process the tubulin network moves in an unknown way. Left: Superposition of all recordings is blurred by this movement. Middle: registered and corrected with a fiducial marker (an artificially included bright shining fluorophore, which can be tracked). Right: Drift correction by a purely statistical method developed in Munk’s group, which does not require this marker. (Hartmann et al. 2016, Drift estimation in sparse sequential dynamic imaging: with application to nanoscale fluorescence microscopy. J. Royal Statist. Society, Ser. B, 78(3), 563–587.)

resolution – higher than the resolution limit set by the diffraction of light. However, a major problem of superresolution microscopy is that the intrinsic random nature of the measurements – where discrete quantum effects are predominant – is rendering conventional solution strategies for statistical inverse problems ineffective.

Surprisingly, and owing to the resolution being extremely small, current statistical laws become untrue and conventional statistical techniques do not allow effective image deconvolution and reconstruction.

OVERCOMING THE PROBLEM OF CONVENTIONAL STATISTICAL LAWS AND METHODS Dr Munk and his group have employed alternative strategies and specific statistical modelling that focus on the underlying random mechanisms. For instance, in superresolution fluorescence microscopy, his research team, in collaboration with

the group of Prof Stefan Hell, has found a statistical way to map the distribution of molecules by exploiting the fact that a single molecule emits only a single photon at a given time. Hence, the light from multiple photons arriving at the same time can, indeed, allow us to quantify how many molecules are present in a specific recording volume. Consequently, stimulated emission depletion (STED) microscopy can provide us with the exact distribution of molecules with subdiffraction resolution. Therefore, researchers are now able to extract a much higher amount of information from such measurements – with given statistical guarantees – by exploiting the discrete physical mechanisms of fluorescent molecules and light, as well as their distributions in time and space.

STATISTICAL METHODS FOR PROTEINMEMBRANE INTERACTIONS Moreover, Dr Munk and his team emphasise

Dr Munk and his team emphasise the analysis of ion channels and the implementation of statistical methods that can be used to model and evaluate electrophysiological data at small temporal scales 56

the analysis of ion channels – channels that regulate all transport processes in the cell membrane – requiring the implementation of statistical methods that can be used to model and evaluate electrophysiological data. These occur when measuring poreforming membrane proteins, one of the most important elements in human physiology because they control the flow of ions – gating – across the cell membrane, thus regulating signal transduction, energy conversion, and transporting.

Therefore, pore forming membranes can be thought of as the regulators that trigger physiological functions, such as a normal heart beat, but also far more complex ones such as walking. This is why ion channels are potential drug targets for central nervous system disorders.

Multiscale ion channel analysis, as developed in Munk’s group, propels the detection of gating characteristics of events on various temporal scales. Dr Munk’s team have been implementing statistical methods that allow for the identification of real gating events – gating dynamics of these channels – with high precision. More specifically, ion channel recordings are subjected to multiresolution statistics, where events are automatically distinguished according to their length and conductivity. The signal is, thus, determined by the time points at which

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Detail Your work has many applications across different fields – do you often collaborate with scientists from nonmathematical backgrounds?

Yes, I have collaborated mainly with researchers from natural science (medicine/lifescience, biology, physics, chemistry), but also occasionally from agricultural and forest science, even philosophy. In addition with several industrial/public sector partners.

Does this type of collaboration have any particular challenges?

Each collaboration requires a reasonably good understanding of the particular subject, which, in turn, requires an effort to learn the specific background to some extent. Intense communication with partners is extremely important: fun but also demanding. In general, statistical and computational methods cannot simply be transferred from one area to another; this always requires good subject knowledge.

However, there are common statistical and computational principles which allow a unifying look at apparently different problems.

Your work into gating characteristics has enabled us to detect these across a variety of temporal scales – can you give examples of these different scales?

A small temporal scale is below a millisecond; a large one parts of a second.

Where do you hope your work will go in the next five years?

Towards development of statistical methodology at a broader range for unravelling nanoscale structures across different temporal and spatial scales, establishing unifying principles and models. We are just at its beginning. As the technical progress of measurement technologies for understanding molecular function at the nanoscale is progressing so rapidly, lab scientists will require more and more sophisticated nanostatistics to evaluate their complicated data and to extract as much information as possible from this.

Intense communication with partners is extremely important: fun but also demanding

events (such as the opening and closing of a channel) occur, and by the conductance in between. However, events to a different conductance level may happen faster than sampled. Therefore, and by means of Jump-Segmentation by MUltiResolution Filter (J-SMURF), the signal at the jump points is segmented and we can effectively determine whether an event was missed or not – even for low signal-to-noise ratio.

The statistical guarantees stemming from this process are unique and have allowed Dr Munk’s team in collaboration with Claudia Steinems lab at Göttingen to demonstrate that, for example, a chemically modified variant of a gramicidin A channel can, indeed, exhibit subgating events.

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Therefore, such an approach is bound to provide a greater understanding regarding the spatial and temporal organization of membrane components and their function.

Dr Munk and his team at the University of Göttingen and in the Max Planck Institute for Biophysical Chemistry are currently performing pioneering research in the field of nanostatistics. Looking to the future, developing methods capable of extracting data and recovering objects from a series of indirect or random measurements at the nanoscale has the capacity to provide the scientific community with a greater insight into the exciting fields of optical nanoscale microscopy and protein–membrane interactions, among others.

RESEARCH OBJECTIVES Dr Munk is a statistician whose research is fundamental to statistical inverse problems and extracts relevant information from complex biological data. He develops specific statistical methods to do this, controlling the level of statistical error for relevant recoveries obtained from the data.

FUNDING Deutsche Forschungsgemeinschaft (DFG), CRC 755, 803 RTN 2088, Max-PlanckGesellschaft, VolkswagenStiftung COLLABORATORS • Prof Alexander Egner • Prof Christian Griesinger • Prof Helmut Grubmüller • Prof Stefan Hell • Prof Thorsten Hohage • Prof Tim Salditt • Prof Claudia Steinem BIO After completing his PhD at the University of Göttingen back in 1994, Professor Dr Axel Munk completed a DFG research fellowship in Philadelphia and Cornell before working as a Research Assistant at Bochum University. He later went on to work as a professor for numerous universities before starting at the University of Göttingen in 2002. Since 2009, he has been the FelixBernstein Chair for Mathematical Statistics and since 2010 he has also worked at the Max-Planck-Institute for Biophysical Chemistry. In 2014 he founded the Felix-Bernstein Institute for Mathematical Statistics in the Biosciences.

CONTACT Prof Dr Axel Munk Fakultät für Mathematik und Informatik Institut für Mathematische Stochastik Goldschmidtstr. 7 37077 Göttingen Germany T: +49 551 39 172111 E: munk@math.uni-goettingen.de

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Psychiatry

Cannabis-based medication may help to treat tics in Tourette’s Syndrome Dr Kirsten Müller-Vahl is a Professor of Psychiatry who specialises in general psychiatry and neurology at the Hannover Medical School in Germany. Her research focuses on examining the underlying neurobiological mechanisms in Tourette’s Syndrome.

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ourette’s syndrome (TS) is a neurological-psychiatric disorder characterised by motor and vocal tics. Motor tics are abrupt and repetitive movements and are among the most prevalent symptoms of the disease, often starting during childhood between ages six to eight. In addition, TS patients often suffer from behavioural deficits such as ADHD, obsessive-compulsive behaviour, anxiety and depression, as well as rage attacks and self-injurious behaviour.

TOURETTE’S & THERAPEUTICS Therapeutic approaches to treat tics have largely focused on behavioural therapy, such as Habit Reversal Training, and psychotropic drugs, predominantly neuroleptics.

However, these have proved challenging.

On the one hand, there are not enough qualified therapists to administrate Habit Reversal Training, so only a small number of patients are offered training places. In addition, neuroleptics such as risperidon, pimozide and aripiprazole, as well as other dopamine blockers, yield unsatisfactory results and come with serious side effects such as sedation, weight gain, and sexual dysfunction.

This has led Dr Kirsten Müller-Vahl of the Hannover Medical School to examine alternative treatment approaches, including cannabis-based pharmaceuticals.

NEUROBIOLOGICAL FEATURES OF TS Though the exact neurobiological mechanisms of TS are not fully known, studies have shown that it involves a network spanning the frontal areas and the basal ganglia areas typically involved in the planning, control and initiation of movement.

Whilst some have suggested that TS may be due to increased activity of striatal neurons in the basal ganglia, others have proposed that frontal lobe dysfunction may be to blame in regulating basal ganglia function.

In addition, neurotransmitters including dopamine, glutamate, and GABA may also be playing a vital role in TS. CANNABIS TO THE RESCUE? Given the unsatisfactory nature of current treatment options, many TS patients have sought alternative therapies. Among them, cannabis was previously found to be successful in weakening the occurrence of tics in TS. That is why researchers, including Dr Müller-Vahl, have spent years examining the effects of cannabis-based medications

Dr Müller-Vahl has spent years examining the effects of cannabisbased medications on the symptoms of Tourette’s syndrome 59

Psychiatry

as well as its active ingredient delta-9tetrahydrocannabinol (THC).

In addition to THC, cannabis contains over 100 cannabinoids as well as plant extracts.

However, the dominant effect of THC can be attributed to cannabinoid CB1 receptors– largely located in brain areas associated with movement control. As such, a higher density of CB1 receptors can be found in the basal ganglia. Furthermore, it has been demonstrated that the endocannabinoid system (ECS) has a modulating function on the brain’s neurotransmitter network. This has led some researchers to conclude that TS could be a dysfunction of the ECS.

CLINICAL TRIALS In 1998, Dr Müller-Vahl conducted a clinical survey among 64 TS patients of whom 17 had reportedly consumed cannabis.

Approximately 82% of these patients reported a reduction in symptoms, and subsequent studies of single cases confirmed that administration of 10mg THC led to an 80% reduction in tics and a simultaneous increase in the attention of patients. A randomised, placebo-controlled six-week trial of up to 10mg THC per day confirmed the previous findings.

However, until more recently, clinical trials into medical marijuana use were largely

The TS-EUROTRAIN training network has the potential to aid in the discovery of new pharmaceutical interventions and ultimately help Tourette’s patients improve their quality of life 60

The TS-EUROTRAIN study sounds fascinating. What are you looking at as part of this collaborative effort?

TS-EUROTRAIN (FP7-PEOPLE-2012-ITN, Grant Agr.No.316978) is a Marie Curie Initial Training Network (http://ts-eurotrain. eu) that aims to elucidate the complex aetiology of the onset and clinical course of TS, investigate the neurobiological underpinnings of TS and related disorders, translate research findings into clinical applications and establish a pan-European infrastructure for the study of TS. This includes the challenges of (i) assembling a large genetic database for the evaluation of the genetic architecture with high statistical power; (ii) exploring the role of gene–environment interactions including the effects of epigenetic phenomena; (iii) employing endophenotype-based approaches to understand the shared aetiology between TS, OCD and ADHD; (iv) establishing a developmental animal model for TS; (v) gaining new insights into the neurobiological mechanisms of TS via crosssectional and longitudinal neuroimaging studies; and (vi) partaking in outreach activities including the dissemination of scientific knowledge about TS to the public.

unavailable in Germany due to legal restrictions. In what is hopefully the beginning of more clinical research into this field, a large study of Nabiximols was approved in 2016. Run by the Hannover Medical School, Dr Müller-Vahl will be the principal investigator of a team examining the clinical effects and side effects of Nabiximols – a cannabisbased medication with the cannabinoids THC and cannabidiol (CBD) (CANNATICS). At the same time, a second study of similar design will investigate the efficacy of THC in combination with Palmitoylethanolamide (PEA) in adults presenting with TS. Dr Müller-Vahl is hopeful that this could offer comparative insights into the effectiveness and tolerance of THC plus CBD, as well as THC with PEA. A third study will investigate how an inhibitor of the hydrolysis of the endocannabinoid 2-AG, ABX-1431, affects the tic symptoms of adults with TS.

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Detail 21 partners, from academia and industry, and 12 PhD candidates, pursue the project. Our ultimate aims are to elucidate the complex aetiology and neurobiological underpinnings of TS, translate research findings into clinical applications, and establish a pan-European infrastructure for the study of TS and associated disorders.

Have there been any trials of THC treatment in combination with behavioural therapy? If so, what was the outcome?

No, however, that would be very interesting.

How effective is surgical intervention in the treatment of TS? There is indeed some evidence that deep brain stimulation is effective in the treatment of TS. However, there is a debate on how and when and in which patients to use it. Most experts think that it should be used only in severely affected, otherwise treatmentresistant patients.

How did you get involved in this field of research?

I started my medical practice as a neurologist and worked together with a very experienced neurologist and movement disorder specialist.

EFFECTS AND SIDE EFFECTS So far, available clinical studies have not found any detrimental effects of THC as part of neuropsychological testing. While cannabis may lead to cognitive impairment in healthy individuals, it seems to have a different effect on TS patients, where it has been shown to boost concentration and visual perception. Though cannabinoids are generally well-tolerated over time, initial psychological effects such as euphoria, relaxation, heightened sensory and emotional perception, as well as disorientation, have been reported.

ON TO BETTER TREATMENT SOLUTIONS As part of her efforts to understand the neurological basis of TS and develop viable treatment strategies, Dr MüllerVahl heads the study group “Tourette Syndrome” in Hannover. In addition, she is second chairman of the “International Association for Cannabinoid Medicines”

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He was interested in tics and so I learnt a lot about movement disorders in general and tics in particular. At that time, very few medical doctors were interested in TS and offered treatment and psychoeducation to patients. Thus, our outpatient clinic grew up quickly and it was quite easy to find patients who were interested in participating in clinical trials. After a substantial number of patients reported beneficial effects of cannabis, I became more and more interested in this area – in particular against the background that all other treatment options have significant drawbacks.

Which therapeutic strategies are safe to use in children?

In children we use the same treatments: Habit Reversal Training and neuroleptics such as tiapride, aripiprazole and risperidone. We only use cannabinoids in otherwise treatment-resistant, severely affected individual cases and normally not before the age of 16 to 17 years. However, with increasing evidence suggesting that cannabis-based medications are effective and safe in the treatment of tics, we will consider using these substances in younger adolescents.

as well as a board member of the "German Association for Cannabinoid Medicines”. Her work has contributed in large to a draft bill by the German federal government to include cannabis as an officially recognised pharmaceutical option.

Additionally, she is part of a large-scale, interdisciplinary investigation into the genetic and pathophysiological factors underlying TS and its associated conditions. The EU-funded Marie Curie initial training network TS-EUROTRAIN is being run across 15 academic partners as well as industry and 12 PhD students.

Researchers are hopeful that the project will offer a more rounded picture of the biological aspects of the disease. This has the potential to aid in the discovery of new pharmaceutical interventions and ultimately help TS patients improve their quality of life.

RESEARCH OBJECTIVES Dr Müller-Vahl’s research focuses on Tourette’s syndrome, and has been particularly interested in determining the neurobiological underpinning mechanisms involved in the disorder.

Her research has also determined that cannabinoids, found in cannabis, can have preventative effects on TS patients and the tics they suffer from.

FUNDING • Deutsche Forschungsgemeinschaft (DFG) • German Ministry of Education and Research (BMBF) • EU (FP7-HEALTH-2011, FP7-PEOPLE2012-ITN) • National Institute of Mental Health (NIMH) • Kröner-Fresenius foundation Pharmaceutical companies COLLABORATORS The CANNA-Tics study will be performed at the Clinical Research Center CRC Hannover, Director Prof C. Schindler. Five other centres will be involved in the study.

BIO Prof Kirsten Müller-Vahl is a Professor of Psychiatry and a specialist in general psychiatry and neurology. Since 1995, she has been the head of the largest specialist Tourette’s clinic in Germany and is involved in several national, European and international scientific projects related to Tourette’s syndrome.

CONTACT Prof Dr Kirsten R Müller-Vahl Klinik für Psychiatrie, Sozialpsychiatrie und Psychotherapie Medizinische Hochschule Hannover Carl-Neuberg-Str. 1 30625 Hannover Germany T: +33511532-3551/-5258 F: +33511532-3187 E: mueller-vahl.kirsten@mh-hannover.de W: https://www.mhh-psychiatrie.de/profmueller-vahl-kirsten

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Improving cybersecurity in an increasingly technological world

Security Engineering

Prof Dr Stefan Katzenbeisser is a Professor for Security Engineering and a member of the Cybersecurity (CYSEC) Profile Area at Technische Universität Darmstadt in Germany. He is a Principal Investigator in the Collaborative Research Center CROSSING and the Center for Research in Security and Privacy (CRISP). He conducts research into IT security solutions for critical infrastructures.

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echnology is now more and more ubiquitous. Devices are increasingly embedded in everyday items, such as consumer electronics, and critical infrastructures, such as industrial equipment and the power grid. This has been termed the ‘Internet of Things’: a phrase which describes how low-end technological devices, that have the capacity to communicate via the Internet, are an intrinsic part of everyday objects.

While these devices have obvious benefits (being able to programme your heating from your phone, for example), the greater interconnectedness increases the attractiveness of these devices for cyber attacks – there are profitable outcomes to targeting software and hardware. In addition, these devices generally lack security hardware to protect against attacks, making them easy, as well as profitable, targets.

Software is more vulnerable to attack from hackers than hardware: to compromise hardware an attacker has to physically change it, unlike software which can be hacked remotely. Therefore, the most reliable way of securing a device is to include a ‘trust anchor’ within the hardware. This trust anchor is generally a small piece of hardware that can bootstrap security for the whole device by confirming that the rest of the device has not been hacked. By installing the trust anchor as hardware, it will not be compromised if the software is corrupted (easy once an attacker has broken in).

Dr Katzenbeisser’s work focuses on two main areas to improve the security of everyday technology: identifying a device and verifying that it is running the correct software.

Finding fingerprints of devices

FINGERPRINTING DEVICES In order to communicate as a device with other devices in the network, a central element of security is knowing who you are talking to.

To identify the different members of a communication network, Dr Katzenbeisser’s team makes use of tiny variations that arise during the manufacturing process, which distinguish devices from one another, giving them a unique signature or fingerprint. These are called Physically Unclonable Functions (PUFs) and can be exploited to implement security in low-tech devices without secure hardware.

Because PUFs are an embodied physical entity, they act as a trust anchor – they can be assumed to be uncompromised. PUFs can be readily evaluated to confirm the device’s identity, but their behaviour cannot be predicted, even if somebody knows the exact manufacturing process that was used.

This means they are easy to make, but virtually impossible to duplicate.

PUFs can also link the use of a particular type of software to a specific device, which protects the programmed code against manipulation by external sources, such as attackers who would like to reproduce it.

Because PUFs are an embodied physical entity, they act as a trust anchor – they can be assumed to be uncompromised 63

Security Engineering

The quality of device fingerprints is experimentally evaluated under different ambient temperatures

DYNAMIC IDENTIFICATION Specifically, the research group of Dr Katzenbeisser and his collaborators have developed a novel type of PUF called a DRAM PUF, which makes use of the dynamic random access memories (where the ‘DRAM’ part of the name comes from) that computers need to function.

DRAM PUFs are an improvement on the ‘intrinsic’ PUFs that are already inherently present in many commodity devices.

Traditional intrinsic PUFs can only be accessed when the device starts up. DRAM PUFs, on the other hand, can be accessed while the device is running, so the identity and security of a system can be queried at any time.

SHHH… IT’S A SECRET Cryptography relies on the use of keys, small ‘secrets’ which must be kept secure. These keys are pieces of information that control the cipher. The PUF can not only generate

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a unique key – a device’s fingerprint – but it can also be used as a storage medium for cryptographic keys. This way, keys can be protected even on a compromised device.

REMOTE ATTESTATION Dr Katzenbeisser’s research also focuses on identifying whether or not a device is running the correct software. This is important because hackers will often try to alter the device's programs to realise their own ends. This verification process is called ‘remote attestation’. Dr Katzenbeisser

has been working on creating protocols to detect the misuse and malfunctioning of devices as early as possible.

Several techniques have been proposed to verify whether or not individual devices have been compromised. A new challenge arises when there are multiple devices in a network, because the amount of information that needs to be transmitted soars at a much greater rate than the number of devices added to the network.

The protocol developed by Dr

Dr Katzenbeisser’s work aims to improve trust and security in an increasingly technological world. His research protects critical data and code from malicious exploitation www.researchfeatures.com

Detail How much is at risk due to the increasing prevalence of technology in everyday items?

A lot. We increasingly rely on networked devices in our daily life. At home, hacked devices may only cause annoyance for their users but, when used to control critical infrastructures, unprotected devices may even undermine the core functions of our society.

How common are cyber attacks on commodity devices?

Hackers have recently identified attacks against devices in the 'Internet of Things' as attractive targets, due to their low level of protection as well as their sheer number. We have recently seen massive Denial of Service attacks, threatening core Internet services, which originated from web cameras and other 'Internet of Things' devices. Attacks against small networked devices are already happening now!

Does the ‘Internet of Things’ represent a positive development?

Yes. Still, we need to assess the risk posed by networked devices. At the moment,

many manufacturers simply add network interfaces to existing products, which were never designed with security in mind. This is the root cause of many security incidents we see in the Internet of Things. We need to establish a new “security culture”: vendors need to care about security as much as they care about user convenience and safety.

How important is it to protect devices from attacks?

Compromised networked devices do not only pose a threat to their owners, but can also serve as a basis for large-scale attacks.

At the same time, we need to make sure that devices controlling critical infrastructures are adequately protected.

What kind of variations are detectable as PUFs? Digital PUFs rely on small manufacturing variations in electronic circuits, such as voltage differences, signal delays or sizes of transistors. Even using advanced production technologies, such minuscule variations cannot be completely controlled by manufacturers.

Katzenbeisser’s team confirms whether devices in a large network have been compromised using ‘heartbeats’. Each device in the network is connected to some other device, and can transmit and receive information. The novelty of Dr Katzenbeisser’s approach is that one ‘leader’ device periodically transmits a heartbeat signal, which is logged and retransmitted by neighbouring devices, together with its own software state. Each device must transmit the most recent heartbeat to be considered uncompromised. Because hackers have to take devices offline to physically tamper with hardware, compromised devices will miss the most recent heartbeat, and therefore be detectable.

identify which devices are compromised, as long as the total number of compromised devices is less than half the network. Other methods cannot pinpoint the problem device, but merely detect that the whole network is unsafe. Thirdly, it also prevents the problem of false positives, whereby issues other than security breaches (e.g., technical failures) cause the protocol to consider the network insecure.

The resulting protocol is scalable and can be used in networks of any size without issue.

It has several advantages over previously developed methods. Firstly, it is much more efficient, which is especially important when networks are large. Secondly, it can precisely

All of Dr Katzenbeisser’s work aims to improve trust and security in an increasingly technological world. His research protects critical code and data from malicious exploitation.

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RESEARCH OBJECTIVES Dr Katzenbeisser’s research focuses on developing IT security solutions tailored to critical infrastructures. He and his team are continuously developing methods and tools to improve cybersecurity and privacy.

FUNDING •T he German Research Foundation (DFG) •T he German Federal Ministry of Education and Research •T he European Commission COLLABORATORS Jakub Szefer (Yale University) BIO Following the completion of his PhD in Computer Science at the Vienna University of Technology, Prof Dr Katzenbeisser has enjoyed a distinguished career as a researcher and professor. He currently works as a Professor at Technische Universität Darmstadt.

CONTACT Prof Stefan Katzenbeisser Technische Universität Darmstadt Mornewegstrasse 32 D-64293 Darmstadt Germany T: +49 6151 1625620 E: katzenbeisser@seceng.informatik.tudarmstadt.de

This work is performed in the Collaborative Research Center CROSSING, funded by the German Research Foundation. CROSSING is dedicated to providing security solutions for new and next generation computing environments.

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Thought Leadership

HAS - giving patients a voice to improve care Of all the many of voices striving to get her attention, there is one in particular that Agnès Buzyn is interested in hearing – that of the patient.

In her role as chairwoman of the board for the French National Authority for Health (Haute Autorité de Santé, aka HAS), Agnès is keen to change the culture of health practitioners in France and put patients at the heart of her organisation’s evaluation system. She met up with Research Features to discuss this, and some of her other healthcare priorities.

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gnès Buzyn is the first female president of the French National Authority for Health (Haute Autorité de Santé, aka HAS). Having dedicated years to medicine, as a doctor, a researcher and a professor, she understands the health system inside out. But it was in her previous post, as president of the French National Cancer Institute (INCa), that her interest in public health really blossomed. One year ago, delighted to find that HAS’ mission and her own personal mission are one in the same – that of improving the quality of healthcare for patients - she agreed to chair the organisation. She spoke to Research Features about her determination to bring fresh ideas to the French health system, while maintaining the best of the old ones.

Hello Agnès! Can you tell us what brought you to HAS and what your role there involves?

I am a medical doctor and spent many years as an academic haematologist and clinician at the University Paris Descartes – Necker Hospital. I then served as president of the French National Cancer Institute (INCa), from May 2011 to February 2016. It was there that I came into contact with public health issues and progressively became more interested

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in that field. HAS’ mission is to improve the quality of care for French patients.

Throughout my career this has always been my goal too, so this mission is of great interest to me.

My role, as Chairwoman of the Board is to advise on public health policies in France.

HAS is governed by a board of seven members and our job is to ensure the best use of the health care system for each patient, and to avoid misuse and overuse of the health care system.

What are the challenges that HAS was set up to address?

We have three main aims. The first one is the qualitative evaluation of all existing health facilities in the French territory. This means we evaluate hospitals, both private and public, for their quality of care and security of care. This information is then made freely available to members of the public, via the website: www.scopesante.fr.

Our second aim is to evaluate health products, drugs, medical devices and medical procedures. Our evaluation shapes the social security’s reimbursement system. In France, health care costs are borne by the patient and then reimbursed,

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Thought Leadership

© Droits réservés, HAS

The HAS building in St Dennis, France

but no medicine can be reimbursed if it has not been evaluated positively by HAS first. Besides, our scientific and economic evaluations help the government to negotiate the prices of medicine with the manufacturers. This is called the health technology assessment mission. It is similar to what NICE does in the UK. We are very, very rigorous on the analysis of conflicts of interest with industry in this area during the expertise process of the evaluation.

Thirdly, we produce recommendations (accelerated developed guidelines, best practice guidelines), to inform our specialists and general practitioners of current best practice. The idea is to harmonise best practice at a national level.

What impact has the organisation had on these issues since its formation in 2004?

I think the quality of care in hospitals has increased. Hospitals are now really aware of the standards we expect to see, with regards to procedures, levels of security and quality of care. Quality of care is a very important issue for hospitals, firstly because they will be judged on it and that judgement will be made public. Secondly because there is a now procedure in France whereby the hospitals which have the best quality of care receive a specific income. So it is important for them, even at a financial level, to have a positive accreditation.

HAS’ recommendations for good practice have a very good reputation in France, because our methodology is very strict and rigorously scientific. There are very, very few criticisms on the quality of our recommendations. The criticism is more on our capacity to actualise these

I am really keen to work with patients. I am interested in patient empowerment, and putting patients at the heart of our evaluation system 68

recommendations when there is innovation involved, because that takes time.

What are your priorities for HAS while you serve as chairwoman?

I have a few priorities for the future. The first one concerns patient involvement.

I am really keen to work with patients. I am interested in patient empowerment, and putting patients at the heart of our evaluation system. At the moment, we have patient representatives in our commissions and in our working groups, but I think that it is not enough. I would really like to see patient empowerment become central to all our evaluations. That would mean changing the culture of health practitioners in France, because they are not used to listening to the patient's perspective on a regular basis. I would say they do listen to patients, but not every day, on every topic.

My second priority is to decrease inequalities in access to our health care system. I would also like to include more preventive measures within our care pathways. Currently, there tends to be more of a focus on treatment, rather than prevention. Although our doctors have excellent training, France is, I think, quite

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behind in prevention policies, compared with other countries.

Finally, I would say that although we evaluate the quality of care in health facilities in private and public hospitals, we do not address the quality of care in the ambulatory sector (health services or acute care services that are provided on an outpatient basis). I would also like HAS to be more focused on the quality of care of general practitioners.

I would also like to see how other countries conduct medical economic analysis of public health strategies. We do evaluate on a medical-economic level. We essentially evaluate drugs and devices, but we are less comfortable in evaluating medical strategies. HAS’ role is to maintain the quality of care and the French national health system within its budget constraints.

In 2016, you became the first woman at the head of HAS. Do you think enough is being done to encourage women into leadership roles in public health?

I think I am very lucky, because France has recently positively updated its gender equality policies. At HAS, prior to my joining, the board of directors was only made up of men. But gender parity has now become mandatory and a new board has just been nominated, this April, half female and half male.

This is more of a personal question. Is it true that as a young girl your weekly cinema trips with your surgeon father were

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© E. Durand, HAS

When considering the improvement of health care, to what extent do you need solutions that address France’s unique health landscape, and to what extent do you look to other countries for inspiration?

We have a unique health landscape because we have our national insurance system, with universal health care largely financed by the government. HAS has a key role in the French system, by evaluating all the health products and all the health procedures for reimbursement. NICE, in the UK, has a similar role, except NICE only evaluates hospital medical devices, whereas HAS evaluates all medical devices, even those that are sold in ambulatory pharmacies.

However, we are very open-minded and are very interested in seeing how it is done in other countries. I am especially interested in seeing the way other countries integrate prevention into the primary care sector, because it is a weakness of our system.

Agnès Buzyn

often interrupted by an emergency call from his clinic, which resulted in you going to the hospital with him?

Yes, it is completely true. I think it gave me a very important insight into what it is to be a medical professional, which I still apply to my patients. When I take the responsibility of being someone’s doctor, that person becomes my priority, because I have the responsibility of that person’s life.

Contact Haute Autorité de Santé 5 Avenue du Stade de France 93218 Saint-Denis La Plaine Cedex France W: www.has-sante.fr @has_sante /Haute-Autorité-deSanté-162499997206968/

Why did you choose to go into medicine?

I was always interested in science, so medicine was an option within the scientific disciplines. I also always liked interacting with people and taking care of them and helping them, in which case to be a medical doctor is a beautiful task.

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Stem cell therapy – the answer to radiation damage The team of scientists at the Institute for Radiological Protection and Nuclear Safety (IRSN) and National Institute of Health and Medical Research (INSERM) aim to develop novel cell therapies for tissue damage caused by radiation. In their latest research, the GIPSIS project, the team investigates the potential of using cutting-edge stem cell therapy to develop a revolutionary approach for the treatment of haematopoietic syndrome – a potentially fatal symptom of acute radiation syndrome (ARS).

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cute radiation syndrome (ARS) is the result of a radiation overdose to the body – a particularly common aftereffect of nuclear war, terrorist attacks or nuclear accidents. It can lead to the life-threatening destruction of stem cells in the bone marrow which play a vital role in producing important blood cells. The last two decades have seen breakthroughs in the field of stem cell research and, as such, stem cells can now be generated artificially in the laboratory. The next big challenge is to leverage existing knowledge to develop stem cell-based therapies for diseases caused by abnormalities in the bone marrow. The consortium from the Institute for Radiological Protection and Nuclear Safety (IRSN) and National Institute of Health and Medical Research (INSERM) is striving to achieve just that, having already made great advances in

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producing blood artificially – this team were the first to produce functional human blood from skin cells in vivo.

442 nuclear power reactors are operating in 31 countries, with sixty-five further nuclear reactors under construction.

SOCIAL, ECONOMIC, ENVIRONMENTAL, AND INDUSTRIAL CHALLENGES ARS is often a result of one of five key events. These include: exposure to a nuclear explosion, a nuclear reactor accident, an accident when handling fissile material, exposure to a powerful beamwidth, or an act of terrorism. ARS was responsible for 180 deaths between 1945 and 2004 from 600 identified radiological accidents – excluding Hiroshima and Nagasaki. A nuclear accident in Chernobyl in 1986 caused over two hundred workers and firefighters to suffer ARS. This event proves that, despite nuclear safety precautions being put in place, nuclear accidents can still happen – and they can be devastating when they do. At present,

Not only that, but numerous nuclear reactors can also be found on military warships – once again demonstrating why the risk of nuclear accidents occurring remains such a major concern for military agencies. Developing and implementing a therapeutic strategy capable of dealing with the radiative effects of nuclear accidents or terrorist attacks, is therefore vital for both military operatives and civilian populations.

ACUTE RADIATION SYNDROME The European Commission has formed a consortium of experts to develop a manual of medical care following accidental irradiation.

This will, in effect, develop a system for assessing organ damage in relation to the

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Blood Generation of induced pluripotent stem cells (iPSCs) for the treatment of haematopoietic syndrome FT FT

Fibroblasts

Healthy donor

iPSC

If severe aplasia persists under cytokines for more than 14-21 days, the possibility of haematopoietic stem cell (HSC) transplantation must be decided.

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FT FT FT

FT FT

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Amplification Transplantation of donor cells

Differentiation of haematopoietic stem cells

Treatment

Creation of clinical grade human iPSC bank as universal source of stem cells – donors chosen on the basis of the selection of the triple homozygotes HLA A, B, DR

Haematopoietic stem cells (HSCs) are produced from fibroblasts taken from a healthy donor. These are then treated to make induced pluripotent stem cells (iPSCs) - these are cells that can become any cell in the body. The iPSCs are then caused to multiply to create a bank of iPSCs. These are then differentiated into HSCs to be used in transplants.

there remains a gap in the management of acute radiation syndrome. The consortium are investigating a new therapeutic approach to bridge this gap and ensure help is available when needed.

time following the accident and classifying this using prognostic codes for the neurovascular, haematopoietic, cutaneous and gastrointestinal systems.

The extent of this accidental irradiation can often be diverse but in the most severe cases stem cell transplants should be considered as a therapeutic option. Currently however, and due to the nature of the incident in which the irradiation occurred (i.e., nuclear accident or terrorist attack), accessing large stocks of stem cells for victims proves difficult. As such,

BEYOND ACUTE RADIATION SYNDROME Chemotherapy in leukaemia patients is, in a way, a voluntary exposure to damaging doses of radiation. The aim is the destruction of cancerous cells in the patient’s bone marrow to subsequently replace them with healthy hematopoietic (blood-cell producing) stem cells (HSC), either from the patient themselves or from a healthy donor.

Haematopoietic stem cell transplantation has become the main treatment used in the management of various haematologic malignancies, but it is not without its issues.

In the European Union alone, over 5000 individuals per year receive HSC transplants for haematological diseases and malignancies.

However, significant numbers of patients (20– 30%) cannot receive the life-saving treatment they require because they cannot access sufficient numbers of HLA-matched HSCs

Acute radiation syndrome is the result of a radiation overdose to the body – a particularly common after effect of nuclear war, terrorist attacks or nuclear accidents www.researchfeatures.com

(this kind of matching uses a protein, human leukocyte antigen, located on the body’s cells – it acts as an indicator to your immune system that your cells belong). Not only that, but treatments often fail due to the matched donor cell not being well-enough suited, resulting in graft vs host disease (GvHD).

In other words, even though donors are carefully matched to maximise the chances of acceptance, graft rejection is common when using donor cells: GvHD contributes substantially to transplant-related morbidity and mortality.

A perfect donor match can only be achieved by using the patient’s own stem cells. This bears the risk that the disease returns because of residual diseased cells in the graft. Nonetheless, haematopoietic stem and progenitor cells, generated from patientderived induced pluripotent stem cells (iPSC), could provide an unlimited supply of HLA-matched transplantable cells capable of treating disease. In 2006, researchers at Kyoto University in Japan identified conditions that would allow specialised adult cells to be genetically "reprogrammed" to assume a stem cell-like state. These adult cells, induced pluripotent stem cells (iPSCs), were reprogrammed to an embryonic stem cell-like state by introducing genes important for maintaining the essential properties of embryonic stem cells (ESCs). Since this initial discovery, researchers have rapidly improved the techniques to generate iPSCs, creating

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Blood

Reprogramming of adult differentiated cells Somatic cells fibroblasts from skin

Ability to differentiate into any cell

Pluripotent reprogrammed cell

Expression of the 4 transgenes

Introduction of 4 transgenes

Self-renewing IPS

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Oct 3/4, Sox2, c-Myc, Klf4 or Oct 3/4, Sox2, Lin28, Nanog

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ion of tr

ansgene

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Oct 4, Nanog, Sox2, c-Myc, Klf4...

TURNING SKIN CELLS INTO BONE MARROW While there is considerable evidence that hiPSCs can form haematopoietic precursor cells in the laboratory, it is less clear under which conditions such cells survive and fulfil their function of forming blood cells in a living organism. Despite high hopes for regenerative therapy, these cells have barely made it into clinical trials so far. Dr Chapel and his team endeavour to change that as

stomach

brain

heart

The process of reprogramming differentiated adult cells is complex – this diagram shows how the cells are taken from skin and reprogrammed using transgenes into pluripotent stem cells which are then able to differentiate into any type of cell

their work on creating blood artificially from fibroblasts shows.

microenvironments, particularly when reaching the adult bone marrow.

This consortium are the first scientists to have obtained a full reconstitution of blood components from iPSCs in vivo in order to develop human blood from adult human skin.

More specifically, they have uncovered a way to convert fibroblasts, taken from skin, into human blood. The discovery could mean that, in the foreseeable future, people who need blood for surgeries, cancer treatments or other blood conditions, such as anaemia, will be able to have blood created from a patch of their own skin.

To generate cells capable of this, the team have designed a dedicated protocol that can be adapted to hiPSCs of diverse origins. This will enable cells to be produced in vitro which display all the features of progenitors capable of endothelial to haematopoietic transition.

THE QUEST AHEAD Although further additional basic research will be required before iPSCs can be applied in the clinic, these cells represent multi-purpose tools for medical research. The team are embarking on a preclinical quest to establish hiPSCs suitable for therapeutic use in humans.

So far, all clinical attempts to do this have failed. However, the team hypothesise that obtaining a less mature cell type might have several advantages over producing an adult HSC. They believe this cell type would display more plasticity in response to changing

The team’s discovery could mean that people who need blood for surgeries, cancer treatments or other blood conditions, will be able to have blood created from a patch of their own skin 72

kidney

tion)

Pluripote

iPSCs built a medical revolution. Like naturally occurring stem cells, such artificially induced cells can self-renew and develop into almost any cell in the body (pluripotency). Human iPSCs (hiPSCs) share this pluripotency with embryonic stem cells but do not cause the same ethical debate because they are derived from adults instead of embryos. They hold tremendous promise for regenerative medicine: researchers might take a person's skin, blood or other cells, reprogramme them into iPSCs, and then use those to grow liver cells, neurons etc. while side-stepping the risk of immune rejection.

liver

s (extinc

Oct 3/4, Sox2, c-Myc, Klf4 or Lin28

a powerful new way to "de-differentiate" cells whose developmental fates had been previously assumed to be determined.

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Day 15-30

This process will evolve in three main stages.

First, the team must demonstrate that their hiPSC-derived haematopoietic cells from healthy donors can form blood cells in a radiation-damaged living organism. To do this, Dr Chapel’s team used a one-step, GMP-grade, vector-free and stromal-free system to produce a cell population capable of reconstituting human haematopoiesis in immunocompromised mice, from hiPSCs. Second, they then must show that hiPSCs from radiation-damaged patients can perform the same function. The final step involves the development of an injectable cell preparation to treat acute radiation syndrome. One major consideration is the safety of this cell-based therapy with regards to recurrence of the patient’s leukaemia or the development of another cancer.

If this team’s proposed therapy passes all its pre-clinical tests, there will be huge potential for entering the clinical trial stage and, eventually, the creation of a patient-specific treatment of ARS and other haematopoietic diseases. However, success in this will depend on the ability to produce clinical grade hiPSCs capable of generating either primitive multipotent stem cells, which will

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Detail Why are patient fibroblasts not damaged by acute radiation?

Because radiation may damage DNA introducing mutations. In cases of accidental irradiation, there is a small part of the exposed victim which is not irradiated. So, first we determine which part of the body has not been irradiated, then we take a small biopsy of skin in order to produce iPSCs after carefully checking that there is no DNA damage.

How long will the GIPSIS project take?

Three years (2014–2017) – it will be followed by another project in order to produce clinical grade cells. The next project will run from 2017 to 2020.

restore damaged organs or replace perfectly mature and functional cells in a substitutive aim. As a consequence of this, the concept of universal iPSC banking makes sense for future development.

BANKING ON STEM CELLS If it is possible to produce clinical-grade hiPSCs, which can then be manipulated to form almost any cell in the body, it is envisaged that a library of hiPSCs from healthy donors could be established. Such donors would need to represent a large part of the population.

Among the tools of regenerative medicine, induced pluripotent stem cells (iPSCs) are interesting because the donor genotype (the type of genes the donor has) can be selected. One proposal to maximise the number of people served by the banks is to create the banks using cells from HLAhomozygous donors. These donors have two identical genes coding for HLA rather than two different ones. However, the creation of this is only achievable through a large-scale concerted worldwide collaboration.

A consortium of 26 partners has already been formed to establish the “European Bank for induced pluripotent Stem Cells” (EBiSC) with support from the Innovative Medicines Initiative (IMI). The EBiSC will act as a central storage and distribution facility for hiPSCs from healthy individuals and patients suffering

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What are the most important quality criteria for a clinical-grade cell therapy?

We are establishing protocols for generation of human induced pluripotent stem cells (hiPSCs) that would not involve viral vector integration, and that are compatible with Good Manufacturing Practices (GMP) standards: no integrative reprogramming, clone selection, absence of mutations on 50 hot spots, GMP, graft without contamination of IPSC, biodistribution to long-term in animal and absence of teratomas, production of cells by a labelled cell therapy unit.

from various inherited diseases, to be used by researchers across academia and industry in the study of disease and the development of new treatments. Furthermore, a Bank of iPS GMP HLA homozygous is under development for future clinical trials in an international consortium involving several countries.

This consortium "Global Alliance for IPS Therapies" (GAIT) will establish standardised procedures.

The medical significance of such a cell library would be enormous. It would not only provide doctors with on-demand cell-based therapy for some of the most severe diseases, but it would reduce the need for time-consuming searching and testing of potential donors. It also reduces the risk of the original disease reoccurring.

Current cell-based regenerative therapies have already delivered substantial advances in medicine. However, this is no reason to be complacent. Existing strategies have considerable limitations we cannot ignore.

In addition, there are several reasons to be watchful of the nuclear risk to human health.

Identifying scalable treatment solutions now may be decisive should a catastrophe strike.

However, even though Dr Chapel’s research currently focuses on ARS, its outcome, if successful, could revolutionise the way clinicians treat any disease caused by cellular abnormalities in the bone marrow.

RESEARCH OBJECTIVES IRSN’s research looks at using haematopoietic stem cell therapy to improve the medical management of acute radiation syndrome (ARS) for members of the military and the public who have been victims of nuclear exposures and accidents.

FUNDING • Direction Générale de l’Armement (ASTRID/ANR program (ANR-13ASTR-0009)) • Etablissement Français du Sang (EFS) (APR 2013 & Combattre La Leucémie) COLLABORATORS Laurence Guyonneau-Harmand, Loïc Garçon, Hélène Lapillonne (CRSA, EFS, INSERM); Bruno L’Homme Marc Benderitter (IRSN); Brigitte Birebent, Nathalie Chevallier, Luc Douay (Unité d’Ingénierie et de Thérapie Cellulaire, EFS); Christophe Desterke (INSERM); Thierry Jaffredo (Sorbonne Universités, UPMC Univ Paris 06, CNRS, INSERM, Laboratoire de Biologie du Développement) BIO For 25 years, Dr Alain Chapel has been developing gene and cell therapy using nonhuman primates, immunetolerant mice and rats to protect against the side effects of radiation. He collaborates with clinicians to develop strategies for treatment of patients after radiotherapy overexposures.

CONTACT Dr Alain Chapel Laboratory of Research on Irradiated Healthy Tissues Regeneration (LR2I) Institute for Radiological Protection and Nuclear Safety (IRPNS) F-92260, Fontenay-aux-Roses France E: alain.chapel@irsn.fr T: +33 615 401931

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Keeping an eye on visual loss through retinal oedema

Ophthalmology

Professor Francine Behar-Cohen, Director of a team at the French National Institute of Health and Medical Research in Paris, and Professor of Ophthalmology at HĂ´tel-Dieu / Cochin Hospital in Paris, has identified crossover targets between the cardiovascular and ocular systems. These innovations may provide more effective treatments for diabetic macular oedema and other retinal diseases.

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receive signals and initiate a response) on the epithelial cell surface (glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) respectively). However, glucocorticoids in particular are known to have activity at both types of receptor. It was this off-target activity, coupled with the successful use of MC antagonists (blocking drugs) to prevent overstimulation of MR in cardiovascular diseases, that led Prof Behar-Cohen to consider their use in the treatment of retinal disease.

rofessor Behar-Cohen is an experienced research director, holding positions in universities, hospitals and industry in both France and Switzerland. Having received numerous awards for her research, her interests include the development of innovative treatments and methods of administration for drugs in the eye. Her particular focus has been on the mechanism of action of steroids and its relation to retinal diseases, and it is here that she has uncovered a largely overlooked issue in ophthalmology.

mostly involved in the regulation of electrolyte balance, via epithelia in the tubules of the kidney. Glucocorticoids are important in the regulation of carbohydrate, fat and protein metabolism, as well as their vasoconstrictive (constriction of blood vessels) and antiinflammatory effects, which are utilised in retinal oedema treatment.

A GOOD PAIR OF EYES The retina (the light-sensing area of the eye) starts life in the embryo as an outgrowth of the brain, meaning that the retina is neural tissue and part of the central nervous system.

It is composed of layers of different cell types, which support and protect the light-sensing rods and cones. These cells gain nourishment from the epithelia (tightly packed cells which form a border or barrier) and the choroid blood vessels, which line the back of the eye. It is this mechanism of layers of cells transmitting a cascade of signals, via the ocular nerve to the visual centres of the brain, which produces vision.

Professor Behar-Cohen’s particular focus has been on the mechanism of steroid action and its relation to retinal diseases, and it is here that she has uncovered a largely overlooked issue in ophthalmology

The correct functioning of the retina is dependent on the fluid balance in the eye and surrounding tissues. Retinal oedema (the build-up of fluid in the tissues making up the retina) is caused by a breakdown in the barrier between the blood and those tissues, poor regulation of fluid withdrawal by glial cells (the nervous system’s protective cells) and retinal pigment epithelium, or other fluid movements in and around this sensitive area of layered cell types.

IDENTIFYING THE ISSUES Current treatments focus on the use of high doses of corticosteroids (steroid hormones), particularly glucocorticoids (GC), which are not well tolerated in longterm use. Corticosteroids are involved in a wide range of physiological processes including the immune response and control of inflammation. Mineralocorticoids (MC) are

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These two classes of corticosteroids have different effects, mediated by their own class of receptors (protein molecules that

A FRESH PAIR OF EYES In recent research, Prof Behar-Cohen and her colleagues have shown that several retinal cell types express the MR, and that activating these by direct injection of aldosterone (a corticosteroid specific for this receptor class) produces effects similar to the symptoms of retinal diseases. Interested to uncover the mechanism underlying these observations,

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Detached macula

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Ophthalmology

Regulation inflammation and fibrosis

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Retinal glial Muller cells Channel regulation, electrolytes and water homeostasis

Diabetic ocular complications

Glucocorticoids Vascular inflammation Vessel stiffness, fibrosis Abnormal vascular reactivity

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Vascular reactivity Vasodilation

Choroidal fibrosis and neovascularisation

the research team found that stimulation of the MR increased retinal thickness and regulated the expression and cellular distribution of ion and water channels. These findings add weight to the hypothesis that MR overstimulation is damaging to the retina and that antagonists for this receptor class may be beneficial in the treatment of retinal disease.

A CLOSER LOOK AT RETINAL TREATMENT Prof Behar-Cohen is now proposing to dig deeper into the underlying causes of these observations, aiming to find molecular targets, downstream of the receptor, which are specific to retinal cell types. This would make it possible to design treatments which did not feature the side effects of a more broadly acting corticosteroid inhibitor. To achieve this they are looking at three specific areas of the retinal tissue: the retinal Muller glial cells (RMG) implicated in oedema, as mentioned previously; the retinal pigmented epithelium (RPE), which nourishes the visual cells and is implicated in subretinal fluid accumulation; and the choroidal vessels, the vascular layer of the eye. Each of these has a vital supporting role, sandwiching the delicate retina between the vital blood supply and the gel-like vitreous humour of the eye.

A second strand of their research is focusing on optimising the use of MR antagonists in the

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treatment of central serous chorioretinopathy using local drug delivery systems and testing whether these new MR antagonists formulations are beneficial for diabetic retinopathy – retinal oedema caused by damage to the blood vessels of the eye due to chronic high blood pressure associated with type II diabetes. One of the current treatments involves the insertion of slowrelease MR antagonists capsule or particulate systems into the eye itself, to achieve a longterm and site-specific MR antagonism.

Stratification of patients presenting central serous and related diseases phenotypes, identification of biologic and/or imaging markers of MR activation and correlation of

phenotypes with biologic markers are another clinical subject of research. This is of utmost importance for the design of future clinical trials. The team is also conducting trials of central serous and other types of macular oedema to define risks and prognosis factors.

LOOKING TO THE FUTURE Identifying antagonist preparations which can themselves be used in this intraocular manner (directly into the eye), is the final aspect of Prof Behar-Cohen’s project. This would allow them to move from cell and animal models of diabetes or overexpressed MR retinal conditions, into clinical cases of retinal disease. Using these models is the first stage, coupling non-invasive in vivo

Prof Behar-Cohen and her colleagues have shown that several retinal cell types express the MR, and that activating these by direct injection of aldosterone produces effects similar to the symptoms of a retinal disease associated with psychological stress, central serous chorioretinopathy, the fourth cause of macular visual impairment www.researchfeatures.com

Detail What is it that you find particularly fascinating about eye research?

Going from patient observation, to basic animal and in vitro, in silico study, and back to clinical application. This translation can be much more rapid due to the fact that we aim at repurposing known drugs. The role of steroids on ocular diseases links stress, environment, immunity and inflammation with retinal diseases.

observation is that retinal oedema is usually ameliorated by glucocorticoids except in the case of central serous, suggesting that those patients may have over activity of MR. Indeed, in patients treated with glucocorticoids, illicit MR occupancy induces hydro-ionic retention by the kidney and oedema. I suspect that similar mechanisms may exist in the eye and this is what we have demonstrated.

Why has finding effective and welltolerated treatments for retinal disorders proved so difficult?

The eye is an isolated organ, which like the brain is protected by barriers, thus ocular drug delivery to the retina is a challenge that limits treatment options. Nevertheless, in the last 15 years, major advances have been made using therapeutic proteins injected into the eye.

How do you envisage being able to target just those receptors in the eye without inducing systemic effects?

When administered into the eye, we do not find circulating steroids elsewhere in the body, demonstrating that local effects are expected.

What led you to examine the mineralocorticoid receptor as a possible therapeutic target?

Glucocorticoids are found in higher levels in the eye than in the circulation, suggesting that they play major and specific roles in the eye but how they act on the retina is incompletely understood.

My interest in MR came from the clinical observations that after glucocorticoids treatment the anti edematous is extremely rapid (less than one hour) suggesting an effect on hydro ionic mechanisms rather than simply on inflammation. The other

measurements of retinal function with cell biology and molecular approaches; this will assess the tolerance and bioavailability of the preparations.

Utilising techniques such as transcriptomics and proteomics (the analysis of all transcribed genetic material in a specific cell population), the team will uncover the specific genes and gene products associated with the aldosterone/MR pathway, in both normal physiological circumstances and those found in retinal disease states, in animal models and in patients. Improving the range of knowledge in this area, which has been lacking to date,

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What is needed to bring effective MR treatments for retinal disease into clinical practice?

Since our first paper in 2012, more than 15 papers have reported use of the mineralocorticoid receptor for the treatment of central serous and associated diseases.

To optimise MR treatment for other ocular diseases and to get approval, we need now to conduct studies on well phenotyped patients with our new formulations. This should be achieved within the next three years. Patents have been granted and pre clinical publications will come soon.

Regulation of downstream targets should be possible in the next five years.

will provide the bedrock for further advances in the treatment of these debilitating and life-changing conditions. The goal is specific biomarker identification and the development of well-tolerated and effective treatments for patients.

It could be concluded that this project is repurposing and reformulating known drugs, widely used in cardiovascular and kidney fields, allowing for quick translation to clinical application. Dr Behar-Cohen’s work is also opening new avenues in the field of the role of stress hormones and ocular diseases.

RESEARCH OBJECTIVES Prof Behar-Cohen’s research interests include the development of innovative treatments and methods of administration for drugs in the eye, particularly for diseases of the retina, and mechanisms of action of steroids and anti-VEGFs in the retina. She has introduced the use of mineralocorticoid receptor antagonists for the treatment of central serous chorioretinopathy.

FUNDING ANR (Agence Nationale de la Recherche), Inserm Transfert (Proof of Concept), UNADEV, FRM (Fondation recherché Médicale) COLLABORATORS Nicolette Farman and Frederic Jaisser (Inserm), Min Zhao, a close collaborator on this project BIO Professor Francine BeharCohen is full professor in Ophthalmology at the University of Lausanne and at the Paris Descartes University.

She is also the director of the Physiopathology of Ocular Diseases: Therapeutic Innovations Team, based in the French National Institute of Health and Medical Research at the Cordeliers Research Centre in Paris.

Prof Behar-Cohen founded the start-up companies Optis France, now Eyegate Pharma and Eyevensys S.A.S. As well as her medical degree, she has gained a diploma of advanced studies in cell biology, a diploma of specialised studies in ophthalmology and a PhD in biology at the Paris Descartes University. Prof BeharCohen was awarded by Oseo-Anvar, Fondation de l’Avenir, Euretina.

CONTACT Prof F Behar-Cohen 15 rue de l’Ecole de Médecine 75006 Paris France T: +33660974419 E: francine.behar@gmail.com

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Biophysics

A fresh perspective into cancer cell development through the mechanics of cell architecture How cells sense and respond to their environment is vitally important to their function within the complex tissues of an organism. Changes in the mechanical properties of cells and tissues, because of exposure to forces, have been linked to diseases such as cancer. This has brought about a new interdisciplinary field of study known as mechano-genetics to further understand the mechanisms involved. Dr Francoise Argoul’s research looks into this, focusing on experimentally characterising the mechanical and genomic responses of cancer cells under external stress.

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ver the past decade, the development of tools capable of mechanically probing cells and molecules in high-resolution detail has facilitated the study of how biochemical factors alter the mechanical properties of cells. This has provided Dr Francoise Argoul and her team at the Laboratory “Ondes et Matière d’Aquitaine’’ (LOMA), Bordeaux, France, with challenging new opportunities to probe the properties of cells. As such, she can now work towards answering some thus far neglected biological questions, informing our fundamental understanding of how changes can cause disease.

Understanding how the mechanical and biochemical properties of a cell influence, for example, the response of a cancer cell to treatment, may be the key to determining why some cancer cells become resistant to interventions. This new avenue of research therefore shows great potential in the development of much-needed novel therapeutics.

MERGING MECHANICS AND GENETICS Mechano-genetics is an interdisciplinary field that brings together elements of engineering, physics, genetics and cell biology to investigate the mechanical properties of

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cells, how changes to these properties occur and how these relate to the genetics of the cell. Cell mechanics control cellular functions so, for a healthy cell, it is crucial that these parameters are maintained. Alterations to cell mechanics are increasingly being discovered to be implicated in a range of human diseases. Therefore, understanding the role of mechanical alterations in relation to cell transformation processes will help establish how malignant cells differ from healthy ones.

Historically, technological limitations in imaging potential have hindered the amount of progress made in uncovering these complex cellular properties. However, in recent years, great advances have been made to develop tools that provide a richer understanding of these factors and how they relate to genetics. This has allowed researchers to take a fresh look at diseases such as cancer and gain a new level of fundamental understanding as to which factors are involved in the invasion of cancerous cells into tissues.

NOVEL TECHNOLOGY TACKLES LONG UNANSWERED QUESTIONS Dr Argoul and her team have contributed a novel set-up of high resolution microscopy to further progress, which they have termed a ‘Bioplasmoscope’. This new device combines

Mechano-genetics is an interdisciplinary field that brings together elements of engineering, physics, genetics and cell biology to investigate the mechanical properties of cells www.researchfeatures.com

Dr Argoul’s Bioplasmoscope apparatus not only overcomes these problems but also offers the possibility to perform simultaneously optical and mechanical image reconstruction thanks to nanoindentation techniques (“acupuncture of cells”) – a means of testing the hardness of small volumes of material – to probe the details of the architecture, the mechanics and the dynamics of living cells. a high-resolution microscope (with or without surface plasmon resonance amplification) and a nano-indentation head (scanning force spectroscopy).

Prior to this, techniques capable of accurately imaging in real time living cells in liquid media, up to nanoscales, had eluded researchers, providing a key issue for gaining deeper insights in molecular biology. Existing

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approaches were invasive and often required the use of fluorescence probes as labels, which consequently can suffer from unreliable photo-stability and can alter the molecular structure of biological complexes. Not only that, but the range of scales that could be attained using fluorescence microscopy techniques, and the molecular components that could be imaged together, was also limited.

STIFFENING LEUKAEMIA CELLS PROMOTES SURVIVAL Dr Argoul and her team have utilised primary chronic myelogenous leukaemia (CML) hematopoietic stem cells as a model to measure the stress-to-strain response of cancer cells, to better understand the modifications that occur to their mechanical properties when they become cancerous.

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Biophysics

Left: Normal hematopoietic cells. Right: The same hematopoietic cells after transfection by the CML oncogene. Photo courtesy of B Laperrousaz

During CML, bone marrow cell density increases, indicating that the physical properties of the hematopoietic stem cells may have changed. Dr Argoul obtained data from cells isolated in healthy and leukaemic bone marrows, and showed that there was a higher degree of stiffening occurring to the hematopoietic cancer cells, as well as more localised rupture events. This indicated that the cancer cells respond to physical force with a cascade of detectable brittle fracture events. These distinct brittle fractures as a response to stress could be used as a marker for how resilient cancer cells are to deformation. Not only that, but they could also be used as an indicator of cancer cell transformation in leukaemia. Dr Argoul’s results also shine light on how leukaemia cells withstand the mechanical constraints posed by their environment, and how these characteristics promote their survival (i.e., how they can resist drug treatments).

MAINTENANCE OF ARCHITECTURE PROVES CRUCIAL FOR HEALTHY CELL FUNCTION The support structure within cells is known as the cytoskeleton, a skeleton-like network

of structural fibres within cells, which consists of dynamically cross-linked biopolymer chains with varying structural properties.

The networks are highly sensitive to physical stress, and have a high propensity for local structural failures; however, the cells also have reparation mechanisms in place that can facilitate the recovery of their original architecture and their dynamical functions (motility, adhesion, mitosis, etc.). If damage to this is too frequent, or the force of a single event is too strong, the repair mechanisms can fail, and the cell can irreversibly lose its ability to regulate its homeostasis, resulting in cellular diseases such as cancer. It is this cytoskeletal disruption that Dr Argoul and her team have identified as one of the hallmarks of CML cancer cells. Hematopoietic stem cells, thanks to their multipotency, can generate a wide variety of blood cells. Unlike other immature blood cells, they can pass the bone marrow barrier to travel in the blood and migrate to other bone marrow niches and differentiate into specialised immune system cells (e.g. the thymus with T-cells). Through her research, Dr Argoul and her team have deduced that it is a change in the mechanical phenotype of some hematopoietic stem cells,

Dr Argoul employs cutting-edge methodology to map DNA replication events to provide new insights into the spatio-temporal control of the process within cancerous cells 80

which could inhibit their migration out of the bone marrow and their division and increase their resistance to treatment.

NOVEL GENETIC PROFILING TO MAP DNA REPLICATION EVENTS Alongside this research, Dr Argoul and her collaborators have also been investigating the genetic characteristics of CML cells, particularly related to their DNA structure.

In partnership with the team of Dr Hyrien who developed cutting edge sequencing tools, they combined RNA (transcripts) and DNA (Okasaki fragments) sequencing from a large population of hematopoietic cancer cells and confirmed that the expression of genes interacting with the CML pathway was changed in the early stage of the synthetic phase (S-phase). More surprisingly, the DNA replication programme was found to be altered in the late S-phase, corresponding to gene deserts located in heterochromatin regions (epigenetics) at the nucleus periphery. Dr Argoul and her collaborators have raised the importance of the combination of different biomarkers (e.g., for transcription, replication and chromatin epigenetics) and multivariate analysis to better understand the temporal and spatial transformation of nuclear functions in CML. Their methodology holds fantastic potential as an efficient tool for cancer diagnosis. Not only that, but its development could also provide more accurate patient prognoses and aid in personalising treatment. Following the success of her work, Dr Argoul now plans to extend the study to two other cancer types: Burkitt lymphoma and soft tissue sarcoma.

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Detail How did you come to apply your understanding of biophysics to cancer cell biology?

I was initially trained as a chemical-physicist, and was interested in complex processes in nature, such as chaos, fractals, turbulence.

In the late 1990s, I decided to move my interests to transdisciplinary questions such as how the mechanics of living systems impact their genetic functions. This type of question emerged progressively in my thoughts because I had been fascinated for more than two decades by the ancestral Chinese methods of acupuncture. Actually, I decided to train (during my weekends and vacations) as a Chinese traditional physician specialising in acupuncture and I completed the qualification for this in 2011. However, given that when you are not also trained for occidental medicine, this medicine is not recognised in France, it was difficult for me to initiate research projects in France on the physics of acupuncture. These years were a great challenge for me and I developed new skills and techniques (both in the laboratory and in my private life) to address very original questions at the frontier of physics, biology and medicine. The question of how physical concepts can help unravel unsolved issues of cancer cell transformation was key and I decided in 2010 to initiate a common project with a team at the Centre de Recherche en Cancérologie of Lyon, for which I immediately got a PhD student and an INSERM funding. I choose the CML because it seemed to me that this type of cancer could serve as a model for many other cancers, which was afterwards revealed to be true.

Since your development of the Bioplasmoscope, how is the technology being implemented in research?

The Bioplasmoscope is more a concept than a limited experimental set-up. The term plasmo can represent the plasmons known in optics, but also the plasma state of matter or the plasma from the blood, or more generally if we take the etymology of this term a form, a shape. This is why we chose this name. This technology is open in the sense that it evolves depending on the technical advances of opto-mechanics and nanosensing. The underlying idea is to

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capture in real time and non-intrusively how living cells adapt or respond to mechanical stresses.

What questions would you like to tackle next in relation to the mechanical properties of cells?

The next question for which I am collaborating with a team from the Institute of Biochemistry and Cell Biology (Bordeaux) headed by Anne Devin is to study how the metabolic functions of living cells interact with the mechanical and dynamical functions of living cells. These dynamical functions rely on a permanent production of energy (ATP) to constantly remodel the cells, adapt their architecture, their motility, adhesion, division, … It is of prime importance that this energy resource be delivered at the place (cell compartment) where it is needed each time. There is therefore a spatio-temporal interplay of the different networks involved in metabolic and mechanical functions to ensure that the cell can perform a specific function.

Are your findings regarding leukaemia cells being translated into a clinical context and how can this be achieved?

In collaboration with a team of doctors from the Bergonié Institute (a research centre for cancer in Bordeaux), we have started a new project that proposes a revisited blood smearing device to assist the diagnosis of blood diseases such as leukaemia and myelodysplasia.

How do you see your research progressing over the coming years?

I hope that our advances in the spatiotemporal control of DNA replication will disseminate the idea that we can no longer limit our sequencing methods to gene expression levels, but that other markers such as replication timing, replication fork polarity and chromatin structure are also fundamental to understand how cellular functions are impacted in cancer. Another aspect on which we are working now is to be able to perform this analysis at the single cell level, to understand better the variability of cancer cell transformations previously observed on cell populations.

RESEARCH OBJECTIVES Dr Argoul is a biophysicist who studies how the profile and mechanical properties of living cells change in the pathology of diseases such as cancer.

To do this, she uses a number of novel, high-resolution techniques to identify and image cancerous cells.

FUNDING L'Agence Nationale de la Recherche (ANR), L’Institut National de la Santé et de la Recherche Médicale (INSERM), l’Ecole Normale Supérieure de Lyon, L’Université de Lyon, l’Initiative d’Excellence (IDEX) de Lyon COLLABORATORS Key Team Members: A. Arneodo, Director of Research (Emeritus), University of Bordeaux, B. Audit, Director of Research, Ecole Normale Supérieure de Lyon Key French Partners: Lyon: Centre de Recherche en Cancérologie de Lyon (F. Nicolini, V. Maguer-Satta, B. Laperrousaz), Institut des Nanotechnologies de Lyon (L. Berguiga) Paris: Institut de Biologie de l’Ecole Normale Supérieure (O. Hyrien) Bordeaux: Institut de Biochimie et Génétique Cellulaire (A. Devin), Bergonié Institute (F. Chibon, G. Etienne) Nantes: University of Nantes (K. Rouger, L. Dubreuille).

BIO Dr Françoise Argoul is a Director of Research of Centre National de la Recherche Scientifique at the Laboratoire Ondes et Matière d’Aquitaine where she manages a research programme devoted to the experimental characterisation of the mechanical and genomic response of cellular systems under an external stress.

CONTACT Dr Françoise Argoul Directrice de Recherche CNRS – Laboratoire Ondes et Matière d’Aquitaine 351 Cours de la Libération 33405 Talence France E: francoise.argoul@u-bordeaux.fr T: +33 (0)5 40 00 61 99

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Economics & Biology

In search of the evolutionary foundations of human motivation For much of the 20th century, the core of economic theory was premised on the assumption that human behaviour is driven only by material self-interest, the so-called Homo oeconomicus model. Dr Ingela Alger, CNRS Research Director in Economics at the Toulouse School of Economics and Biology Programme Director at the Institute for Advanced Study in Toulouse, is combining her knowledge of economic modelling and evolutionary biology to investigate the evolutionary foundations of human motivation. This work, mainly conducted together with Jörgen Weibull, Professor at Stockholm School of Economics and Visiting Professor at the Institute for Advanced Study in Toulouse and the Toulouse School of Economics, has led to the discovery of a kind of human motivation that has hitherto not been studied in economics, a motivation they have baptised Homo moralis due to its inclusion of a moral component.

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tarting in the 1990s, the longstanding assumption that human behaviour is driven by self-interest was shaken by data showing inconsistencies with predictions based on pure material self-interest.

In experimental scenarios used to test economic theories, people were found to be more generous, cooperative and compliant than the models would suggest. In extreme cases, changes in material incentives were found to induce behavioural changes diametrically opposed to those anticipated.

Increasing fines, for example, has sometimes been found to lead to more infringements of the rules; whilst employees who are given stricter performance criteria sometimes exhibit reduced performance.

A NEW MODEL This data made it clear that a richer model of human motivation is required for effective policymaking, particularly in the sphere of the provision of public goods. This is exactly what Dr Alger is attempting to provide together with her co-authors. She is developing the hypothesis that individuals are able to make fully rational assessments of their circumstances and opportunities, but that despite this knowledge some choose options which do not result in maximal material gain for themselves. This begs the question of which preferences are driving this decision, and researchers have proposed a range of possibilities from pure altruism to habit formation and aversion to lying.

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Much experimental work has been conducted in an attempt to better understand the preferences driving human behaviour and to try and provide an improved model. This has mainly served to underline the initial observation that Homo oeconomicus is not a robust representation, and shown that there is a great diversity of behaviours which complicates classification. The thrust of Dr Alger’s work is to pare this experimental corpus back to first principles, and from there to develop testable predictions about preference distributions in a given population, based on evolutionary logic.

BRING IN THE BIOLOGISTS The focus switches to evolutionary biology because economists would like to find a theory for which of these preferences will emerge and persist in society. Research in the 1990s considered populations where individuals are randomly matched together to complete some task for the public good.

In this scenario, preferences produce behaviours and these behaviours have an impact on an individual’s reproductive success (biological or cultural) – preferences which produce behaviours with a positive impact on reproductive success then increase in frequency within the population.

This preference may then become evolutionarily stable if mutant preferences are unable to produce an increase in reproductive success.

This model led to the discovery of a kind of human motivation that has hitherto not been studied in economics, a motivation Dr Alger and Dr Weibull call Homo moralis www.researchfeatures.com

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Economics & Biology

Capitole, a social sciences university in France, IAST specialises in this approach: their stated goal is, “to break down artificial disciplinary boundaries, to bring together researchers from all over the world… [and to] unlock new ideas to address the challenges of the 21st century”. One of the techniques they use is to host conferences and workshops addressing this specific interface between economics and biology, inviting researchers from both fields to attend.

Dr Alger and Dr Jörgen Weibull developed a model which also incorporates an element of assortative matching, whereby the pairing of individuals with mutant preference types are promoted, a situation they believe better reflects the pattern of observed human behaviour than models without such assortative matching. This model led to the discovery of a kind of human motivation that has hitherto not been studied in economics, a motivation Dr Alger and Dr Weibull call Homo moralis due to its inclusion of a moral component. Interestingly, the Homo moralis motivation can help explain behaviours that are hard to explain with other classes of motivation used in economics (see Alger and Weibull, 2016).

NO MEAN FEAT Identifying more gaps in the current literature, Dr Alger’s latest project, together with Dr Weibull and Laurent Lehmann, Professor in Biology at the University of Lausanne, further deepens the link by

allowing for explicit patterns of migration within the population: this allows for a more fine-grained analysis of the assortative matching, and for an explicit modelling of the tendency for assortativity – which promotes morality – to be accompanied by local competition for resources, a force which promotes spiteful behaviours. Together with Dr Weibull she has also studied how an individual’s ability to display their own preferences to others, and perceive others’ preferences displayed to them, might impact on the evolution of those preferences within the population.

Bringing together these elements from the studies of both economic theory and evolutionary biology, Dr Alger heads the Human Motivation Evolutionary Foundation Project. Collaborating with researchers from The Institute for Advanced Study in Toulouse (IAST), the team are drawing on crossdiscipline expertise to address the problem.

Supported by the Université de Toulouse

A richer model of human motivation is required for effective policymaking, particularly in the sphere of the provision of public goods 84

Dr Alger is harnessing this inter-disciplinary approach to take advantage of evolutionary biologists’ experience of analysing the evolution of behaviours in assortative matching scenarios, a situation which is common in populations where dispersal of offspring is limited. Coupling this with the economists’ understanding of the evolution of preferences allows the team to build a bridge between the two and apply biological principles to evolution, including cultural evolution. The success of this approach is clear from their publications in high-quality journals in both economics and theoretical biology.

MODEL, TEST, DISSEMINATE, REPEAT The research will be in three parts: theoretical analyses using standard tools from microeconomic theory, game theory, evolutionary game theory, and evolutionary biology. The findings will then be tested by using numerical simulations where appropriate and by running predictions against existing experimental data. Finally, they will review the implications of their research on public policy and open channels to policymakers to affect change where possible.

Dr Alger is keen to continue to promote the collaborative nature of the project by disseminating her findings as widely as possible, publishing in peer-reviewed journals with high impact to engage with academics across research fields. Already a popular speaker in both fields, she will continue to present her findings, and her vision, to researchers and students in economics and biology. However, it is in delivering her findings to stakeholders in policymaking circles that the real-world impact of this research will be felt, and Dr Alger is keen to connect with these networks.

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Detail What do you personally find interesting about the field of theoretical economics?

Theoretical economics engages hundreds of economists to seek patterns that may explain the structure of human societies and economies as well as human behaviour. Such patterns are explored by way of mathematical models. People are often surprised by the extensive use of mathematics in economics, but this use is highly valuable. Firstly, it ensures that the theoretical arguments are internally consistent and thus protects the researcher from drawing erroneous conclusions (although care must of course be taken to ensure that the model assumptions are sensible). Secondly, the reliance on mathematics allows us to rigorously explore the limitations of the theoretical arguments.

In sum, theoretical economics provides a powerful set of tools to understand human societies.

What are the main challenges in testing such complex theoretical scenarios?

The main challenge is to find datasets that allow us to disentangle alternative theories.

The field of experimental economics has developed precisely for the purpose of collecting datasets in controlled environments, but economists also benefit from data collected by government agencies and sometimes by firms.

Another challenge consists in resisting the temptation to interpret correlation as proof of causality. Economists are known to be quite obsessive when it comes to causality: more and more sophisticated methods are developed to avoid interpreting correlation as proof of causality, but of course these methods require appropriate datasets to deliver adequate testing of alternative theoretical scenarios.

How does collaborative working help to address those challenges specifically?

As in many realms of human life, scientific research within any given discipline is nowadays characterised by high levels of specialisation. For the same reason, different disciplines have come to specialise increasingly on a subset of ideas or methods. This specialisation in turn

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means that different disciplines may have developed bodies of knowledge that are complements rather than substitutes.

This complementarity creates a strong potential for productive inter-disciplinary collaborative efforts.

What will be the likely impacts on public policy from this research?

Research that allows us to better understand the motivation behind human behaviour improves the prospects for policy-makers to design policies that will achieve what they are supposed to achieve.

Firstly, such research will pave the way for more accurate data analysis, because it will allow us to narrow down the set of alternative theories. Hence, the predictive power of empirical analysis should increase. Secondly, a better understanding of human motivation should allow a better understanding of which policies will likely receive stronger support than others.

Do you envisage other areas where evolutionary biology and social sciences might interact?

Yes, I believe that there are quite a few areas where biological and social sciences may fruitfully interact. This is particularly true when it comes to providing concrete solutions to address the urgent and complex long-term challenge consisting of ensuring the sustainability of human life and welfare.

It is my firm belief that appropriate answers to this challenge cannot be provided by researchers from one single discipline. In particular, tools and data from economics and from ecology will need to be combined to understand how renewable and non-renewable resources can be managed in a sustainable way, and which institutions and policies governing economic exchange would allow us to achieve such management. As a step in this direction, in Toulouse we have created a multi-disciplinary advanced master in Economics and Ecology.

RESEARCH OBJECTIVES Dr Ingela Alger’s research bridges the gap between biology and economics, looking at the evolutionary foundations of motivations behind human behaviour and what this implies for economics.

FUNDING Agence Nationale de la Recherche (ANR) COLLABORATORS • Jörgen Weibull (Stockholm School of Economics and Institute for Advanced Study in Toulouse (IAST)) • Laurent Lehmann (University of Lausanne) • Donald Cox (Boston College) • Hillard Kaplan (University of New Mexico) BIO Dr Alger, MSc in Economics, Stockholm School of Economics, completed her Economics PhD at Université des Sciences Sociales in Toulouse. After 14 years abroad, she became CNRS Research Director at Toulouse School of Economics.

Since 2012 she is also Biology Programme Director at Institute for Advanced Study in Toulouse.

CONTACT Dr Ingela Alger Toulouse School of Economics 21 Allée de Brienne 31015 Toulouse France E: ingela.alger@tse-fr.eu T: +33 561 128 517 W: www.tse-fr.eu Alger and Weibull, 2016: Alger, I., Weibull, J., “Morality: evolutionary foundations and policy implications”, TSE Working Paper, n. 16702, September 2016

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Biofluids

Modelling and characterisation of microcapsules Dr Salsac’s research focuses on the dynamics and mechanical behaviour of microcapsules and their subsequent interactions under the presence of an external flow when placed in suspension. This is an exciting field with potent applications to biofluids and vascular mechanics (e.g., flow of red blood cells in the microcirculation), and to the encapsulation of active substances (e.g., pharmaceuticals, cosmetics). The ability to model and characterise artificial microcapsules could hold the key to optimising drug delivery to specific cells or tissues.

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icroencapsulation is the process of enclosing a core substance within a micrometric-sized particle.

Microcapsules are liquid droplets protected by a thin, deformable membrane with elastic properties whose size can vary from a few micrometres to millimetres for the largest ones. The reticulated membrane governs the deformation of the capsule when it is placed in suspensions, and controls the exchanges between the internal and external fluids.

THE IMPORTANCE OF MICROCAPSULES Micro-encapsulation is a prominent means of protecting a liquid internal

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medium and allowing its subsequent controlled release if desired – through adaptation of the membrane’s mechanical properties and porosity. Even though this is a well-known technique – in fact, the first microencapsulation procedure was published back in 1931 – recent technological developments have allowed microencapsulation to become a very

significant part of scientific research with a number of industrial applications.

CHALLENGES FOR AN OPTIMISED USE OF MICROCAPSULES Undoubtedly, the most challenging aspects of generating efficient microcapsules is to ensure their stability, and control their deformation in external fluid environments.

This requires controlling the deformability of the capsules as well as their dynamics when in suspension.

Owing to the strong fluid–structure interactions with the confined fluid flows, the capsules can be deformed in a complex way under the formidable hydrodynamic stresses. In order to deeply understand their dynamics, there is a need to generate numerical models that predict the behaviour of capsules under hydrodynamic stress,

Undoubtedly, the most challenging aspect of generating efficient microcapsules is to ensure their stability, by controlling their deformation in fluid environments

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Figure 1.

Microfluidic technique for the controlled generation of microcapsules. 1. Channel of injection of the HSA solution. 2.

Channel of injection of the oil phase. 3. Channel of injection of the reticulating agent. 4. Serpentine to enable membrane reticulation.

5. Cylindrical channel enabling the mechanical characterisation of the microcapsules. 6. Reservoir.

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100 μm 5

6

1 cm

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Biofluids

and to conduct microfluidic experiments of capsule suspensions flowing in microchips.

The other challenge is to design techniques to characterise the mechanical properties of entire capsule populations and ensure that they have the desired behaviour for each application. Micropipette aspiration or indentation by atomic force microscopy have the drawback of necessitating micromanipulations on individual particles, which is cumbersome.

The development of microfluidics has led to new techniques of characterisation to be devised: the membrane resistance is determined from the flow of capsule suspensions in microchannels, provided one can numerically model the capsule deformation under the exact same flow conditions as those prevailing in the microsystem.

This concept of combining highly complex numerical modelling with microfluidic experiments is exactly what Dr AnneVirginie Salsac’s work in the Biomechanics & Bioengineering Laboratory of Université de Technologie de Compiègne intends to achieve. This will, in turn, allow for the design and fabrication of microcapsules, specifically customised to satisfy the demands of each industrial application.

MICROCAPSULE FABRICATION USING MICROFLUIDICS With the possibility of using photolithography to create microfluidic systems with an infinite number of designs, new techniques of microcapsule production have been designed. Dr Salsac’s group has developed a microfluidic technique (Figure 1) that allows for the fabrication of finely calibrated microcapsules, both in terms of size and mechanical properties.

It relies on a flow-focusing system to first generate droplets, around which a membrane is then produced by crosslinking. Cross-linking refers to the formation

Figure 2.

Spherical capsule flowing in a cylindrical or squaresection tube at equal flow rates.

Figure 3. Successive profiles of a microcapsule flowing in a microfluidic channel with a sudden expansion

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of bonds between molecules that can be polymers, proteins, etc. The degree of membrane reticulation is defined by the mean velocity of the suspending fluid, and by the length of the serpentine channel, in which the drops circulate and react under the effect of the reticulating agent injected through the second flow-focusing system.

MODELLING OF MICROCAPSULES' MOTION IN HYDRODYNAMIC FLOW To study the motion of microcapsules in confined or infinite flow conditions, Dr Salsac and her group develop numerical models that have the capacity to predict the deformation of microcapsules according to their intrinsic physical properties and

Dr Salsac’s pioneering research in the characterisation of microcapsules has the capacity to provide the scientific community with a greater insight on a field that has many industrial applications 88

200 μm

provide measurements of non-measurable quantities, such as the stress level in the membrane, to evaluate the risk of rupture.

The team has developed and implemented second-order finite element-boundary integral (FE-BI) methods that allow for the modelling of initially spherical or anisotropic capsules, and of their flow in infinite or confined environments such as the microfluidic pores shown in Figure 2. Using shell elements, they have, for the first time, modelled the effects of the finite thickness of the capsule wall and compared the results to ones predicted by the zero-thickness membrane models.

CHARACTERISATION OF MICROCAPSULES Dr Salsac’s group have developed an innovative method for characterising the deformability of a population of microcapsules, as opposed to existing techniques that can only characterise individual ones. This microfluidic method allows cross-linked microcapsules to flow into a cylindrical microchannel, where deformation takes place. Consequently, and

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Detail Why did you first become interested in this area of research?

Being specialised in biofluids applied to vascular mechanics, I am interested in the understanding of the blood flows from microcirculation to the haemodynamics in large blood vessels. Microcapsules, which are models of natural cells, provide an insight into the behaviour of red blood cells and open the way to the study of blood microcirculation.

What applications are there for microcapsules in general?

Over the last decades, small-scale encapsulation has become ubiquitous.

Besides its classical use in cosmetics and personal care products, it is at the source of innovative applications, many of them appearing in the fields of biotechnologies (encapsulation of drugs for drug therapy or cells for artificial organ generation), food industry (encapsulation of aromas, nutrients, or active substances to produce neutraceuticals), agriculture (encapsulation of fertilisers) or energy storage (encapsulation of phase-change substances for new insulation technologies).

Can you give an example of how the knowledge gained from your research could be applied?

The beauty is that the research combines very fundamental aspects (advanced numerical models of the complex fluidstructure interactions of micro-objects) and very practical applications: for

by means of a fast camera mounted on a microscope, both the deformation and the speed of the microcapsule can be measured.

The deformed shape is then compared to developed models, predicting deformations under the same flow conditions.

Similarly, the group has developed other microfluidic-based techniques of characterisation. Using a microchannel which includes a sudden expansion from a rectangular to a square cross-section, they have, for instance, measured the viscoelastic properties of protein-reticulated microcapsules (Figure 3). The viscoelasticity

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International collaborations constitute a real strength and a source of mutual enrichment instance, it enables prediction of the behaviour of microcapsules upon injection, and determination of their mechanical properties using in batch technologies.

You are the Visiting Professor at Queen Mary University, London and completed your PhD in the US. How important is international collaboration to your work?

International collaborations are particularly crucial to our community, as it consists of a limited number of groups working worldwide on the numerical and experimental modelling of microcapsules.

They constitute a real strength and a source of mutual enrichment.

What are the next steps for this research?

The next step is to further study the processes of release of the encapsulated medium and its interactions with the capsule flow and deformation.

is determined from the characteristic time of relaxation of the capsule after the expansion.

In the Biomechanics & Bioengineering Laboratory of Université de Technologie de Compiègne, Dr Salsac’s team is currently performing pioneering research on the characterisation and modelling of microcapsules. Looking to the future, Dr Salsac’s investigations have the capacity to provide the scientific community with a greater insight into a field that has many industrial applications.

RESEARCH OBJECTIVES Dr Salsac’s research focuses on the dynamics and mechanical behaviour of microcapsules and their interactions with an external flow when placed in suspension. Her latest research has looked at modelling and characterising microcapsules under hydrodynamic stresses.

FUNDING Agence nationale de la recherche (ANR) COLLABORATORS • Dominique Barthès-Biesel, Eric Leclerc, Anne Le Goff, Badr Kaoui (BMBI Laboratory, UTC Compiègne, France) •F lorence Edwards-Lévy (URCA Reims, France) •P atrick Le Tallec (Ecole Polytechnique, France) • Marina Vidrascu, Miguel Fernandez (INRIA Paris, France) • Marc Leonetti, Julien Deschamps, Marc Georgelin (Aix Marseille Université, France) • Yi Sui, Wen Wang (Queen Mary University of London, UK) BIO After graduating from UC San Diego in 2005 with a PhD in Biofluids, Anne-Virginie Salsac spent two years at University College London as a Lecturer.

She was recruited by the CNRS in 2007 and joined the Biomechanics and Bioengineering Laboratory at UTC (France). In 2014, she was nominated Visiting Professor at Queen Mary University of London.

CONTACT Dr Anne-Virginie Salsac Biomechanics & Bioengineering Laboratory (UMR CNRS 7338) Université de Technologie de Compiègne rue Personne de Roberval, CS 60319 60203 COMPIEGNE cedex France T: +33 (0)3 44 23 73 38 E: a.salsac@utc.fr W: www.utc.fr/~salsacan/

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COMMUNICATION RESEARCH NEWS

Why science must combat sensationalism I remember once whilst flicking through a certain popular newspaper, I noticed a headline claiming that ‘one glass of red wine a day prevents breast cancer’.

Naturally, like anyone, I became intrigued, and delved right into the content.

Now, I guess I’m different to most other readers, as I already have an academic background in science, so I more-or-less know how to smell rubbish when it is staring me in the face.

Reading the article in front of me, the first half carried on with the sensationalised theme of red wine as the miracle cure for breast cancer. Fantastic news if true, but highly doubtful – especially when included on page 36.

It wasn’t until the very last paragraph that anything of any scientific merit was included, finally mentioning the actual research the claim had been based on. And boy, did the rubbish smell fresh.

(yes, I checked) did it say anything about red wine or the influence drinking one glass a day would make. Nor did it specifically mention breast cancer.

There are so many other examples of this – you only need to ask the person sitting next to you to hear some of the scientific claims that people have heard.

Research actually shows that drinking one glass per day can be bad for health, and can actually be a causative effect towards breast cancer – but that’s beside the point.

This is why you as a researcher need to ensure that your work is represented in a way that is accurate, true and accessible to the general public. With the growth of modern-day media streams – whether it be Facebook, Twitter, TV, radio, whatever – information is everywhere, and it is vital that people know what to believe.

To the average viewer reading this extensively exaggerated, fabricated claim, they may not think to question the scientific validity behind it and will take it as fact.

Research even shows that people lose their attention as quickly as eight seconds now, so a lot of readers wouldn’t have even reached the paragraph discussing the actual research itself.

Together, scientists can stop sensationalism.

The research was actually conducted on the cells within the skin of a type of grape used to make a particular type of red wine.

Nowhere in the actual research paper itself

With the growth of modern-day media streams, information is everywhere, and it is vital that people know what to believe

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