International Center for frontier research in chemistry HIGHLIGHTS 2007/2012
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The President’s
EDITORIAL
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A Center of Excellence in Chemistry
HIGHLIGHTS
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Foster a world-class research in our network in
CHEMISTRY AND ITS FRONTIERS
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Actions
2007 – 2012
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Support for
INNOVATION PROJECTS
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Support for
TRANSNATIONAL COLLABORATIONS
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Support for
LOCAL COLLABORATIONS
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What happened?
EVENTS
Création graphique : Fanny Walz • Crédits photographiques : Couverture : Ekaterina Shilova/Fotolia – Sommaire : CNRS Photothèque/ICGM/LMIS1/Juergen Brugger, Frédéric Favier, Vahid Fakhfouri ; Vincenzo Palermo ; Nicolas Busser ; Nicolas Busser ; CNRS Photothèque/Christophe Lebedinsky ; Bernard Braesch – p. 1 : D.R. – p. 2 : CNRS Photothèque/François Jannin ; Nicolas Busser ; CNRS Photothèque/Alexis Cheziere ; Pascal Disdier ; Nicolas Busser ; CNRS Photothèque/CEMES-LAAS-LLN-CRTBT ; CNRS Photothèque/Alexis Cheziere – p. 4 : D.R. ; D.R. ; Catherine Schröder – p. 5 : Stéphane Louis ; Elsa Pfimlin – p. 6 : Mir Wais Hosseini ; Jean Pierre Bucher – p. 7 : Elena Savinova – p. 8 : Philippe Mesini – p. 9 : Pierre Braunstein – p. 10 : Nicolas Giuseppone – p. 11 : Luc Averous ; Pierre Schaaf – p. 12 : Vectorlart/Fotolia – p. 13 : Uladzimir Bakunovich/Fotolia ; Yury Zap/Fotolia – Autres visuels : tous droits réservés. • Impression : CG Photogravure, Eckbolsheim
The President's
EDITORIAL
C Bernard Meunier President of the icFRC
hemistry holds a central position at the cross-road of basic sciences and their technological applications (e.g. therapeutics/ healthcare, materials/information technology, etc). For Strasbourg, chemistry has always been a core strength upholding its reputation of excellence in both research and education. Over the past years, the Shanghai Academic World Ranking of Universities ranked Strasbourg in the top 20 worldwide in the field of Chemistry, being the only French entity appearing in the top 100. The Strasbourg chemistry is also characterized by its large volume of contracts and grants, its technology transfer efforts (filing of numerous patents, creation of start-ups and industrial links) and its international attractiveness (50% of the PhD students are coming from abroad). In 2007, in a national competition, Strasbourg was selected for the establishment of a thematic network for advanced research in chemistry. This was a new tool setup by the Ministry to further strengthen sites where France excelled in a given field. To ensure a flexible and responsive administrative structure, each network was given an endowed foundation. The Strasbourg network for chemistry, with the acronym icFRC in English (CiRFC in French), was thus able to operate immediately with a small but effective staff to implement the project and provide the support to the research teams in its Network. In this context, the success of the icFRC scientists in the 2010 Labex program should be noted: several research groups raised 35 M € for a 9 year period for 3 different projects. In addition, the Network was strengthened by 2 Equipex awards of ca. 20 M €. The icFRC scientific directions are therefore naturally defined by the visions articulated in these 3 Labex projects, the main one being that centred on chemistry, namely the chemistry of complex systems. The icFRC also regroups scientists from biology to physics at the interface with molecular science that are involved in new drug development and in the study of the interactions between nanostructures and their environment. The operational strength of the icFRC since 2007 has enabled it to amplify the efforts of its members and to bring together the research teams of 14 research laboratories and institutes of the University of Strasbourg and the CNRS within a comprehensive strategy for the site. The icFRC will continue its efforts and stay focused on its mission by supporting and encouraging the excellence of the chemistry in Strasbourg.
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A Center of Excellence in Chemistry
HIGHLIGHTS
Supporting a network of excellence 76 research teams
238 researchers
14 research units
754 scientists
424 doctorates & post-doctorates
8 fields of excellence*
* physical chemistry, coordination and catalysis, drug and therapeutics, modeling and theory, organic and bioorganic, polymers and materials, supramolecular, solid and inorganic.
1st
in France – top 20 in the Academic Ranking of World Universities.
Academic leaders 2 10
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“Laboratories of Excellence” projects granted in the French “Excellence Initiative” program.
Technology transfer • 540 contracts generating
Nobel Prize Laureates
Laureates of ERC Grants
7
Members of the French Academy of Sciences
9
active Members of the “Institut Universitaire de France”
95 m€ in revenue since 2008 • 80 patents • 20 startup companies
Research support • 86 research projects supported • 8,1 m€ distributed
Plus numerous awards and distinctions
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A Center of Excellence in Chemistry
HIGHLIGHTS
Scientific impact Scientific production 1996 – 2012 7 120 publications
Scientific production 2008 – 2012 2 300 publications
28,5
1 035
citations/ publications
publications co-signed with an international team
430 publications cited more than 100 times
180 publications among the 5% most cited in the world in the field of chemistry
H point Average H point: 32 Highest H point: 131
About 40% with H point > 30
An attractive network 53% of our doctoral students and post-docs come from abroad.
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Foster a world-class research in our network in
CHEMISTRY AND ITS FRONTIERS The foundation supports the recruitment of high-level scientists of any nationality and provide them funding for their installation.
Examples of newly recruited members • Jean–François Lutz • Jean–François Lutz is one of the leaders in Polymer Chemistry at the University of Strasbourg. Coming from Potsdam University, he joined Strasbourg and our network in 2010. His research group “Precision Macromolecular Chemistry” explores the interfaces between conventional synthetic polymer chemistry, organic chemistry and biochemistry. “Working in Strasbourg was always a dream for me. This is definitely the strongest place for Chemistry in France. There is so many world-leading scientists in this city: Jean-Marie Lehn, Jean-Pierre Sauvage, Thomas Ebbesen, Jean-Paul Behr, Pierre Braunstein, Gero Decher and many others. This is indeed a great privilege to interact with such influential scientists. This will certainly have an impact on my future research.” (Polymer Chemistry Author of the week by Remzi Becer, web writer, 12th Jan 2011)
• Joseph Moran • Joseph Moran joined the University of Strasbourg and our network in 2012 to lead the “Laboratory of Chemical Catalysis”. “Chemistry at the University of Strasbourg has an outstanding international reputation. In particular, the senior members at ISIS are all at the top of their fields and have been very successful in obtaining funding. As a young scientist, having such colleagues is an inspirational and educational experience. That is why I made the move!” “The financial support from the FRC was absolutely essential for my move to Strasbourg. Europe has taken some important steps towards encouraging young independent researchers, such as the establishment
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of the ERC Starting Grant, but those are typically awarded 3-5 years after starting an independent position. There must be therefore sufficient startup funds offered by the home institution and related organizations such as the FRC. When you factor in the potential to win an ERC StG, Strasbourg becomes quite attractive internationally for a young scientist, but this would not necessarily be the case without FRC support.”
Launch of the AXA-University of Strasbourg Chair in Supramolecular Chemistr y The AXA Research Fund, a world-wide initiative of scientific philanthropy supported by the global insurance group AXA, awarded 2.25 m€ to the University of Strasbourg to create a Chair for Supramolecular Chemistry, now held by Professor Luisa De Cola. Her work will follow the research begun by Professor Jean-Marie Lehn. Prof. De Cola is a top world class researcher in the field. She has an international career, studying in Italy and the USA and has held several professorships, in Switzerland, the Netherlands, and Germany. In 2011 she was the recipient of the Distinguished Women in Chemistry Award. Her presence will ensure that Strasbourg continues to be a center of excellence and will help the University to lead the way in the coming decades. Strasbourg, January 10th 2013 Launch of the AXA University of Strasbourg Chair on Supramolecular Chemistry, in the presence of Henri de Castries, AXA Group Chairman and CEO.
Actions
2007 – 2012
Research
Education
The foundation federates a broad network of researchers working in the field of chemistry and its interfaces with physics, material science and biology. Our network builds on the long and outstanding tradition of chemistry in Strasbourg including scientists such as Louis Pasteur, Charles Gerhardt, Adolf von Baeyer, Emil Fischer, Hermann Staudinger and most recently Jean-Marie Lehn (Nobel Prize 1987). Spread out over three Strasbourg campuses, in Cronenbourg, Illkirch and the Esplanade, the RTRA is a multidisciplinary network that makes it possible to cover a broad array of subjects ranging from fundamental concepts to applied research and to address them in an interdisciplinary way. The foundation aims to bring a new dynamic and a new effectiveness in response to the global challenges of our time. It offers various accompanying measures to support research through its calls for proposals and by contributing to the organization of high-level events (conferences, seminars, workshops, etc.). Following are some examples of the research support the FRC has provided.
Each year the foundation awards scholarships to encourage students in chemistry and acknowledges the excellence of its students with prizes. The foundation supports international conferences and encourages its PhD students and post-doctorates to participate to these events. Some of our actions are mentioned below.
• Calls for Proposals • Financial support is awarded to innovative and cooperative research projects between the teams of our network. The support is attributed to allow the recruitment of Ph. D. students, post docs, or engineers, but also for the acquisition of equipment and the covering of operating costs. The selection process is carried out by international peer review and the Scientific Advisory Board.
More than 8 m € dedicated to 90 research projects. • Supports for technological platforms• We support the development of several instrumental platforms in Strasbourg, funded largely with the national and regional government’s contract and managed by the foundation.
More than 9 m € dedicated to equipment in Strasbourg on the 3 campus.
• Scholarship in Chemistry • Thanks to our donors, 12 scholarships for Master degree students have been established since 2009. The FRC awards 2 to 3 scholarships per year to Master degree students in Chemistry. The selection is based on need and the performance in their studies. Students with their scholarship donor (NovAlix)
“I was a cashier for about two years before I decided to go back to studying Chemistry. It was in 2008. I’m now a Master degree student in Molecular and Supramolecular Chemistry. Thanks to this Scholarship, I can complete my graduate studies with confidence and free of financial worries.” Dimby Rasoloarison
• Best Student Oral Presentation FRC Award • The FRC awards each year one PhD student in chemistry, during the “Journées Campus Illkirch” (JCI), which takes place annually on the Illkirch campus of the University of Strasbourg. This event offers to the participating research units an opportunity to present their current work. Researchers have a chance to learn more about research carried out in nearby laboratories and discuss science. Ms. Elsa Pfimlin received in 2012 the “FRC Best Student Poster Presentation Award” for her research project entitled “Rationalizing the discovery of non-peptide agonist to explore central roles of vasopressin and oxytocin receptors”. She is a PhD student at the University of Strasbourg, under the supervision of Prof. Marcel Hibert. Her research focuses on the design of a central non-peptide oxytocin agonist as a treatment for autism spectrum disorders.
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Support for
INNOVATION PROJECTS Coordination networks
Strapped porphyrin based molecular turnstiles Synthesis of a series of molecular turnstiles bearing both H-bond donor and acceptor sites.
ª The design was based on tetraaryl X2SnIVporphyrins (X = Cl or X = OH) as H-bond acceptor stators equipped with a rotor bearing a pyridyldiamide moiety as a H-bond donor. In solution, using 1- and 2-D NMR techniques, it has been shown that the switching between the closed state resulting from the formation of intramolecular H-bonds and the open state of the turnstile may be achieved using external H-bond acceptor molecules such as DMSO. The solid state structure of the closed state of the turnstile was established by X-ray diffraction on single crystal.
A strapped porphyrin (a) and a turnstile that contains both H-bond-donor and -acceptor sites in its closed (b) and open states (c).
Published in :
T. Lang et al. Chemistry Eur. J., 33, 10419–10426 (2012) A. Guenet et al. Chemistry Eur. J., 17, 6443-6452 (2011) Ò Institut Le Bel – Laboratoire de Chimie de Coordination OrganiquE
Molecular nanoscience
Spin injection for magnetic spectroscopy and spin transport in single objects (SPINMASTER) Employing for the first time a spin-polarized scanning tunneling microscope (SP-STM) to accurately study the spin-transport through nano-objects.
ª To study the spin-transport through nano-objects, a magnetic tip was progressively moved into contact with a single atom or molecule adsorbed on a magnetic or non-magnetic surface, while concomitantly monitoring changes in the differential conductance. Compared to other techniques, STM provides a better knowledge of identity, location, and number of atoms/molecules in between the leads, molecular orientation or binding site, which are expected to significantly affect conductance properties. The impact of the magnetic coupling between the tip and an atomic contact is monitored by varying the tip-atom/molecule distance by means of an atomic/molecular spacer which allows exploring the Kondo and spin accumulation effects. The C60 molecule was also used to study the incidence of the molecular conformation on the spin transport. A low-temperature STM operating in a clean, ultra-high vacuum environment with an in situ magnetic vector field was specifically developed for this purpose in collaboration with Createc, a leading company in scanning probe microscopes.
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Cobalt-phthalocyanine (CoPc) molecules adsorbed on cobalt nanoislands grown on Cu(111). Published in :
C. Lacovita et al. Phys. Rev. Lett., 101, 116602 (2008) J.P. Bucher et al. Nature Nanotech., 5, 315 (2010) Ò Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) – Département des Matériaux Organiques (DMO)
Support for
INNOVATION PROJECTS Electrochemical systems
Cooperative behaviour of nano-objects under the electrochemical control Understanding and controlling the cooperative behaviour of an assembly of electrochemically active nano-objects spatially distributed on a support.
ª Bistable kinetics is a key for understanding such biological processes as cell differentiation or apoptosis but also for the design of new multifunctional materials. In such systems, the nature and the strength of coupling between the individual bistable elements may lead to the emergence of cooperativity. Two complementary approaches were utilized in this project in order to shed light on the role of coupling phenomena in electrochemical systems. In the first approach utilization of a three-dimensional array of active nano-objects allowed us to unveil the mechanism of the electrochemical oxygen reduction, one of the most significant reactions in chemistry and biology, whose mechanism is much debated in the literature. In the second approach we used an array of individually addressable platinum microelectrodes and applied it to a model bistable reaction, the electrooxidation of CO. This led us to discovery of new types of cooperative behaviours such as sequential activation and dynamic
switching of active elements. The figure shows how Pt microelectrodes spontaneously switch in a sequential manner when the global rate of the carbon monoxide electrooxidation is linearly increased through the applied current (a), and how the mathematical model developed within the project captures the essential features of this behaviour (b). Published in :
P. S. Ruvinskiy et al. Special issue of Electrochimica Acta, 84, 174-186 (2012). D.A. Crespo Yapur et al. ChemPhysChem, under revision. Ò École de Chimie PolymèreS et Matériaux (ECPM) – Laboratoire des Matériaux, Surfaces et Procédés pour la Catalyse
Therapeutic Chemistry
Design, synthesis and biological evaluation of peptide-mimetic ligands as RFamide receptor antagonists Discovery of novel therapeutic agents for the treatment of pain.
ª All these receptors (NPFF1&2, GPR10, GPR54 and GPR103) present endogenous peptidic ligands exhibiting a shared C-terminal signature (Arginine-Phenylalanine amide). In addition, modulation of function of these receptors by means of selective antagonists or agonists may interfere with nociceptive/pain molecular pathways and thus constitute novel therapeutic approaches for the treatment of pain, especially hyperalgesia observed in numerous pathologies (cancer, diabete, neuropathies…). Different approaches were followed: 1) development of short dipeptides and non-natural α-amino acids derivatives; 2) peptidomimetics; 3) Non-peptidic drug-like heterocycles.
START-UP ª The development of the first orally-active NPFF antagonist able to reverse at low dose the opioid-induced hyperalgesia in rats and mice. This work strengthens the portfolio of patents dealing with NPFF receptor antagonists as antihyperalgesics and will support the founding of new a start-up company dedicated to novel therapeutic treatments of pain.
Published in :
R. Gealageas et al. Bioorg Med Chem Lett, 22, 7471-7474 (2012) H. Hammoud et al. J. Med. Chem. (2013) submitted F. Bihel et al. J. Med. Chem. (2013) submitted Ò Faculté de Pharmacie – Laboratoire Amidines Endogènes et Synthétiques
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Support for
INNOVATION PROJECTS Self-Assembly
Nanohealth Small molecules that self-assemble into nanotubes in organic solvents.
ª We have synthesized and studied small molecules that self-assemble into nanotubes in organic solvents with diameters of about 30 nm and lengths of several micrometers. The shape of these objects has been characterized by freeze fracture TEM and their inner and outer diameters by small angle neutron and X-ray scattering experiments. When they self-assemble, the nanotubes form gels in solvents and those gels can be easily transformed into aerogels. The constituting molecules are synthesizable at large scale, which make them good candidates to develop new materials, which is the aim of our project. In this perspective, we have suitably functionalized of the compounds to make them chemically reactive while they retain their self-assembling properties. We obtained from these analogues nanotubes with the same size but endowed with reactivity: they can covalently link small molecules either in the gel state or aerogel state. We are currently using these materials as low-density supports for water remediation.
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A: Cryofracture-TEM of the self-assembled nanotubes in solvents. B, C: SEM micrographs of the aerogels formed from the same nanotubes after supercritical drying. D: aerogel formed from nanotubes with alkyne surface functionalization.
These nanotubes have also been used as porogens to form catalytic mesoporous all-polymeric materials. The same self-assembled compounds were also used as templates on surface to align Au nanoparticles into parallel size-sorted rows. Published in :
N. M. Sangeetha et al. ACS Nano, 6, 8498-8507 (2012) T. T. T. Nguyen et al. J. Mater. Chem., 22, 7712-7714 (2012) Ò Institut Charles Sadron (ICS) – Laboratoire Systèmes Complexes Moléculaires et Macromoléculaires Organisés
Support for
TRANSNATIONAL COLLABORATIONS Molecular metal clusters
New functional polynuclear transition metal architectures for magnetic and catalytic properties Design of metal complexes to be used as precursors in homogeneous catalysis.
ª Coordination clusters of the transition metals attract considerable interest owing to their diversified and tuneable structures and their often unique magnetic properties. Special efforts are currently directed towards the synthesis and characterization of Single Molecule Magnets (SMM). Our own focus on nickel complexes originates from applications in the field of catalytic ethylene oligomerisation where the search for selective formation of short chain oligomers, in particular tri- and tetramers, represents a major academic and industrial challenge. We found that some of these complexes displayed very promising magnetic properties and this resulted in the desire to investigate more closely systems containing Ni(II) ions, and for comparison, Co(II) ions with the same ligands. The reactions of various pyridine-alcohol ligands with Ni(II) precursor complexes represent an efficient way to generate a range of novel polynuclear
View of the crystal structure of a coordination cluster with a NaNi6 core resulting from the assembly of incomplete cubane-type units.
View of the crystal structure of a cubane-type tetranickel complex.
complexes containing Ni4 cubane-type entities. We have characterized very unusual polynuclear complexes with a Ni7, NaNi6 or Na3Ni4 cores, compared their properties and found that some novel Ni4 cubanes with chloride bridges display SMM behaviour. Published in :
Laure Kayser et al. Chem. Commun., 46, 6461–6463 (2010) Roberto Pattacini et al. Dalton Trans., 40, 10526–10534 (2011) Sophie Hameury et al. Dalton Trans., (2013), accepted for publication Ò Institut de Chimie – Laboratoire de Chimie de Coordination in collaboration with the Universities of Karlsruhe and Freiburg.
Nanochemistry
Optically Responsive Monolayers: functional nanosystems and Field-Effect Transistors Organic field-effect transistors (OFET) from flexible and versatile organic material components.
ª Transistors are the fundamental unit in modern electronic devices. New materials are continually being sought to increase the functionality and control over the organic field-effect transistors (OFET) using not only electric fields, but also other stimuli such as light. To this end, our group has been pursuing the preparation and testing of materials coated with light sensitive molecules (e.g. azobenzenes) with the ultimate aim of influencing their performance by shining light of the appropriate wavelength on them. We have coated the gold electrodes of a fieldeffect transistor using a self-assembled monolayer of azobenzenes and incorporated in the channel an organic semiconconducting small molecule. By illumination of the device with light at specific wavelengths we have tuned reversibly the charge injection at the electrodesemiconductor interface, a process that is rule
by tunneling. We have also successfully incorporated azobenzene units onto the surface of gold nanoparticles, which not only allows for reversible control over their solubility through irradiation, but when mixed with an organic semiconductor, it allows for a modulation of the charge trapping/detrapping process in the organic semiconductor film. Importantly, we have also shown that properties such as the surface wettability and the work function of gold, which is a crucial parameter related to the ability to control electrons in these devices, can be reversibly modified by irradiation of an azobenzene coated gold surface, and that the magnitude of this effect can be tuned through careful design of the azobenzene molecules used. Published in :
N. Crivillers et al. Adv. Mater., 23, 1447-1452 (2011) (Highlighted in Nat. Mater. 2011, 10, 264) C. Raimondo et al. PNAS, 109, 12375-12380 (2012) N. Crivillers et al. Adv. Mater., 25, 432-436 (2013) Ò Institut de Science et d’Ingénierie Supramoléculaires (ISIS) – Laboratoire de Nanochimie in collaboration with the Universities of Karlsruhe and Basel.
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Support for
TRANSNATIONAL COLLABORATIONS Supramolecular Chemistry
Synthesis, morphology studies, and optoelectronic properties, of hierarchically self-assembled donor-acceptor nanostructures Discovery and the implementation of a firmly new kind of responsive self-assembled triarylamines units.
ª In industry, triarylamine-type molecules have been inserted in numerous electro-optical devices such as organic light emitting diodes (OLEDs), organic solar cells, organic field effect transistors (OFETs), nonlinear materials, and even used as photoconductors for the Xerox® process in laser printers and photocopiers. However, this molecular core has never been described as a structuring precursor that would be able to selfassemble in ordered supramolecular architectures, possibly with enhanced physical properties. In this project, we have described a firmly new kind of responsive self-assembly process that rests on simple light exposure of triarylamine derivatives. Moreover, we have demonstrated that the generated molecular stacks can combine into very strongly packed bundles of larger fibers and, by taking advantage of their light-triggering capability, we have determined their conductivity properties when spontaneously trapped between metallic electrodes. Interestingly, these fibers display extraordinary metal-like conductivity properties similar to sorted metallic single-wall carbon nanotubes.
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This work has been highlighted by a national press release of the CNRS on April, 5, 2012 and by numerous articles published in the national and international media, such as Angewandte Chemie.
The first generation of supramolecular tirarylamine nanowires (STANWs) already presents tremendous potential for making novel addressable supramolecular electronics and we are currently working on their chemical modification to study their structure / property relationships. Published in :
E. Moulin et al. Angew. Chem. Int. Ed., 49, 6974-6978 (2010) V. Faramarzi et al. Nature Chem., 4, 485-490 (2012) E. Moulin et al. Adv. Mater., 25, doi:10.1002/ adma.201201949 (2013) Ò Institut Charles Sadron (ICS) – Laboratoire Synthèse et Auto-assemblage Moléculaires et Supramoléculaires in collaboration with the University of Freiburg.
Support for
LOCAL COLLABORATIONS Biobased polymers
Enzymatic polymerization to elaborate organic/inorganic hybrid materials for biomedical applications Developing original catalytic systems based on immobilized enzymes
ª Immobilized enzymes (lipases) are efficient for the synthesis of biopolyesters and allow the preparation of organic/inorganic nanohybrids based on clay nanoparticles grafted with such polyesters. Sepiolite and montmorillonite nanoclays were used as lipase supports and the clay-immobilized forms of Candida antarctica lipase B (CALB) were tested for ε-caprolactone and lactide isomers polymerization. The immobilized enzyme catalysts showed higher efficiency for the synthesis of polycaprolactone biopolyesters. Polymerization kinetics and characterization of resulting materials have shown that lipases immobilized on montmorillonite show better performances compared to the ones immobilized on sepiolite. Clay
surface organo-modification has also proved to greatly enhance the catalytic activity of the corresponding systems. Lipase immobilized on montmorillonite allowed the elaboration of organic/inorganic nanohybrids as evidenced by the effective grafting of polyester chains from the clay surface. Finally, random polycaprolactone/polylactide copolyesters were successfully obtained by lipase-catalyzed copolymerization of D-lactide with ε-caprolactone. Ò École de Chimie Polymères et Matériaux (ECPM) Laboratoire Biopolymères-Bioplastiques Ò Faculté de chirurgie dentaire Biomatériaux et ingénierie tissulaire
Polyelectrolyte multilayers biomaterials
Schematic representation of a cryptic site surface. Ligands (RGD peptides) are embedded in a poly(acrylic acid)/ poly(allylamine) multilayer (PAA/ PAH) (a) At rest, RGD peptides are buried inside the film; (b) under stretching RGD peptides are accessible to cells.
Enzymatically active materials reversibly controllable by mechanical stretching Chemo-mechano-responsive materials
ª Over the last years, mechanical forces have started to emerge in chemistry mainly through the investigation of mechano-transduction processes in biology. Cell fate and tissue morphogenesis are largely governed by the mechanical properties of tissues and forces applying on cells. This raises the fundamental question: how do cells sense mechanical properties and how are mechanical forces transduce into biochemical reactions? One way that nature uses to transducer forces into chemical reactions is by using cryptic site proteins. These proteins exhibit active sites when brought under mechanical tension. We tried to mimic at a macroscopic level such a behavior by creating surfaces with embedded ligands or active sites which can be exhibited by stretching. We used two systems, biotin/streptavidin and RGD peptides/cells, as model systems. The ligands (biotin or RGD) were grafted onto poly(acrylic acid) chains. These chains were embedded into poly(acrylic acid)-PC/ poly(allylamine) multilayers (PC: phosphorylcholine groups). By stretching, the ligands were exhibited and
thus became accessible to the receptors. The second path that we followed is to extend our first work where we incorporate enzymes into a gel-like polyelectrolyte multilayer covered by a barrier against the substrates. By stretching the barrier renders the enzymes accessible to the substrate. In a new design we incorporate the substrates into the gel-like multilayer and adsorb the enzymes on top of the barrier. By stretching the barriers allows the substrate to diffuse through the barrier and to interact with the enzymes. The reaction takes place at the interface and the product diffuses towards the solution. Published in :
J. Davilla et al. J. Am. Chem. Soc., 134, 83 (2012) C. Vogt et al. ACS Macro Letters, 1, 797 (2012) Ò Institut Charles Sadron (ICS) – Laboratoire Polymères et Interfaces Ò Faculté de Pharmacie – Laboratoire de Biovectorologie
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What happened?
EVENTS 2007 Inauguration of the International Centre for Frontier Research in Chemistry
2008 First icFRC awarded research projects selected by the Scientific Council
2009 Launch of the Scholarship Program to Support Master’s Students in Chemistry at the University of Strasbourg
2011
2010 Launch of the first fundraising campaign in partnership with the University of Strasbourg Foundation
2011
Launch of 2011 International Year of Chemistry in Strasbourg by Prof. Jean-Marie Lehn
Prof. Jules Hoffman, the 2011 Nobel Prize in Physiology and Medicine
2012 French Excellence Initiative: Three LabEx Projects Granted in the Field of Chemistry and its Frontiers in Strasbourg
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2013 Launch of the AXAUniversity of Strasbourg Chair on Supramolecular Chemistry
Missions of the icFRC Maintain the high level of excellence of research in chemistry in Strasbourg Recruit and retain top junior and senior talents on both a national and international level Increase the attractiveness of the Strasbourg site Provide flexible and responsive support for innovative projects Promote local and international collaborations Promote transfer of knowledge and technologies and encourage teams to work with partners in industry
Major Projects Support dedicated to the recruitment of very high-level international researchers Calls for Proposals – research funds dedicated to collaborative and innovative projects Scholarship for students in chemistry – training the future researchers Partner of several scientific events – spreading knowledge around the world
Fondation icFRC International Center for Frontier Research in Chemistry
8 allĂŠe Gaspard Monge F-67000 Strasbourg administratif@icfrc.fr www.icfrc.fr