©Marcel Kipke
A continuous system for pharmaceutical processing Batch processing is a well-established method in the field of pharmaceutical processing— but in the face of mounting pressure to improve productivity and reduce manufacturing costs, researchers are increasingly looking for alternatives. We spoke with Dr. Janina Bahnemann about her work in developing an integrated continuous flow system. The pharmaceutical industry
is a major player in the European economy, and pharmaceutical companies are always keen to further refine and improve the efficiency of their production methods. The majority of biopharmaceuticals are currently manufactured using long-standing batch processing methods—but that may soon begin to change, with the rise of continuous bio-manufacturing systems. That topic lies at the heart of Dr. Janina Bahnemann’s research. “Our group is particularly interested in integrated continuous flow systems because we are aiming to develop more flexible methods of producing recombinant proteins for pharmaceutical processes,” she explains. While traditional batch cultivation and production processes are safe and wellestablished, they are also time-consuming, inflexible and do not allow product quality controls - significant downsides which have spurred researchers to investigate alternatives in recent years. “Companies simply don’t want to invest months of work in establishing one single cell line for the production of a new antibody,” stresses Dr. Bahnemann.
Transient transfection Industrial-scale continuous cultivation and production systems might allow pharmaceutical companies to significantly trim back that lead time. On a smaller scale, researchers in Dr. Bahnemann’s group are currently using continuous transient transfection methods to rapidly deliver a gene of interest into a host cell, instead of establishing the stable transfection of cells. “Mammalian cells have the ability - using the gene of interest - to produce antibodies or proteins, or whatever target it is that the gene codes for,” she explains. This continuous transfection system could be integrated into a bioreactor, which would then enable scientists to manipulate cells over time and thereby greatly improve the efficiency of production. “Using this method, cells can produce a protein continuously because they are essentially being transfected over and over again,” notes Dr. Bahnemann. Dr. Bahnemann’s immediate aim is to achieve the efficient and reproducible transfection of mammalian cells. The next step will then be to develop a system for
incubating such cells along with the plasmids containing the gene of interest. “We are ultimately looking to develop a cell separation system in order to separate our cells from the old medium and the transfection buffer,” she says. “The goal will be to transfer the transfected cells into a fresh culture medium, to then continue with the production of our protein of interest.” This system would open up the possibility of producing several different proteins in parallel with one another. Researchers in Dr. Bahnemann’s group are already developing a small-scale microfluidic system through which several different proteins could potentially be produced at the same time when integrating the system into a bioreactor. “We could use different plasmids with different genes of interest, and achieve parallel cultivation and production,” she observes. The cultivation parameters would usually be identical, with Dr. Bahnemann and her colleagues also developing biosensors to act as an online monitoring system. “The biosensors will monitor the cultivation system and alert
Feed bioreactor Cells
Monitoring Biosensors
Reaction reagent Transfection reagents
Lab-on-a-chip LOC
Old medium
Fresh medium
Cell retention
Production bioreactor
DNA
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EU Research
Development of integrated continuous flow systems Development of integrated continuous flow systems Project Objectives
us to the presence of any contaminants which is critical to ensuring the quality of the eventual product,” she stresses. These biosensors will enable scientists to quickly identify any shifts that take place within the system and assess in real time whether changes or modifications are required - for example, modifying key parameters such as the buffer, pH level, or nutrient supply. “Because we are receiving this information in real time, we can very quickly ascertain whether our system is working well or not. And if we see that something is starting to go wrong, we can step in and take a deeper look. It’s a very dynamic model,” says Dr. Bahnemann. Additional biosensors can also be integrated into the microfluidic system to monitor the proteins that are produced, thereby allowing Dr. Bahnemann and her colleagues to assess the productivity and
Personalised medicine The system that Dr. Bahnemann envisions holds tremendous potential in the field of personalized medicine. Continuous biomanufacturing systems could facilitate the safe and efficient development of medicines that are tailored directly to the needs of individual patients - which is especially useful in the case of ‘rare’ diseases, which, for economic reasons, are not a major priority for big players in the pharmaceutical industry. “When your focus is large-scale production, batch cultivation is desirable because it’s important to establish the stable transfection of cells. But if the focus is personalized medicine - for example, if you want to treat a disease with a low incidence rate that affects only a small proportion of the population - then it’s very useful to focus on smaller-scale production systems,” explains Dr. Bahnemann. “We can use such systems to
Our group is particularly interested in integrated continuous flow systems because we are aiming to
develop more flexible methods of producing recombinant proteins for pharmaceutical processes. performance of the cells. “We can not only determine whether our protein of interest is being produced, but also identify the specific concentration of production,” she explains. Because perfecting adaptable and versatile biosensors that can consistently serve these purposes is a critical part of any continuous cultivation and production process, they are a central point of interest for Dr. Bahnemann’s team. “In the future, I envision that biosensors like the ones we are working on might be used not just in our cell cultivation system, but also on biomedical or even environmental samples,” she says. The ultimate aim is to develop a system for the production of recombinant proteins that is not only just as safe, efficient, and consistent as current methods, but also far more flexible. “We are currently working to develop a microfluidic system that achieves the efficient and reproducible transfection of mammalian cells, so that we can essentially insert the plasmid with the gene of interest and thus allow a continuous and flexible protein production,” continues Dr. Bahnemann.
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produce small amounts of common proteins, or to produce very rare proteins, in a costefficient manner that simply isn’t possible using traditional production methods.” A continuous cell transfection and cultivation system would also be of great interest to medical research departments. More efficient production of antibodies and proteins would help to facilitate research into their effectiveness and wider medical potential. “After a protein has actually been produced, researchers can check the bioactivity to see whether or not the product is actually efficacious,” says Dr. Bahnemann. Because many rare proteins are either extremely difficult to produce, or are not commercially viable to produce on an industrial scale, Dr. Bahnemann’s research into smaller-scale production methods holds tantalizing promise in this field as well. “We are currently working on producing our first proteins for research purposes. Because there’s such a great need in research applications for the production of certain types of growth factors, this is one of our top priorities at the moment,” she explains.
With the design, fabrication and integration of different functional microfluidic based devices this project pursues the construction of a novel controlled and continuous cell cultivation process for recombinant protein production and simul-taneous analyte monitoring. Main features of the integrated system will be (1) a microfluidic LOC device for continuous gene delivery to the production cell line, (2) a continuous cultivation of the transfected cells in small perfusion culture reactors and (3) a novel electro-mechanical aptamer-based biosensor for specific monitoring of model target proteins and early detection of contamination. The final goal is the establishment of a parallel process for continuous gene delivery and production of various target proteins simultaneously.
Project Funding
This is a DFG Emmy Noether project. http://gepris.dfg.de/gepris/ projekt/346772917?language=en
Project Partners
• Prof. Michael R. Hoffmann, California Institute of Technology (Caltech), Pasadena, USA • Prof. Ester Segal, Israel Institute of Technology (Technion), Haifa, Israel
Contact Details
Project Coordinator, Dr. Janina Bahnemann Emmy-Noether Fellow Institute of Technical Chemistry Gottfried-Wilhelm-Leibniz University Hannover Callinstr. 5, 30167 Hannover, Germany T: +49-511-762-2568 E: jbahnemann@iftc.uni-hannover.de W: https://www.tci.uni-hannover.de/ ak_jbahnemann https://scholar.google.de/citations?user=S1H xpLkAAAAJ&hl=de&oi=ao Dr. Janina Bahnemann
Dr. Janina Bahnemann is a Junior Research Group Leader for Cell Culture and Microsystems Technology at the Institute of Technical Chemistry at Leibnitz University Hannover. Her main research interests lie in cell culture technology, bioprocess technology, microsystems technology, additive manufacturing/3D printing, and biosensors/bioanalytics
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