Day 2 :
Merck Millipore Germany
Keynote: Chemically modified cysteine in fed-batch processes and impact on CHO specific productivity
Time : 10:00-10:30
Based in Darmstadt, Germany, Aline is currently responsible for the development of mammalian cell culture media at Merck Millipore. Aline holds an engineering degree in biochemistry and biotechnology from the National Institute of Applied Sciences (INSA) in Lyon, France, a master in cellular physiopatho logy from the University of Lyon and a PhD degree in immunology from the University of Paris. She has worked 3 years in immunotherapy biomarker research at Stallergenes before joining Merck KGaA in 2011. From 2011 to 2012, Aline was responsible for the development of cellular assays to monitor upstream processes at Merck Millipore. From 2013 to 2014, Aline was heading the R&D upstream media performance laboratory responsible mainly for the development of new chemically modified amino acids and their integration in fed-batch platforms. Since April 2014, Aline is heading the mammalian cell culture media development activities at Merck Millipore.
Industrial fed-batch cultivation of mammalian cells is used for the production of therapeutic proteins such as monoclonal antibodies. Beside medium ensuring initial growth, feeding is necessary to improve growth, viability and antibody production. Established commercial systems include a slight acidic concentrated main feed and a separate alkaline amino acid feed containing L-tyrosine and L-cysteine. Since L-cysteine is not s table due to its dimerization to cystine in the presence of air and metal catalysts, a stable L-cysteine derivative is needed to include all amino acids in neutral pH feeds. Those single feed systems are favored to simplify feeding schemes and improve the overall process robustness through stabiliz ation of both pH and DO signals. Here, we suggest the use of a chemically modified cysteine in combination with phosphor tyrosine disodium salt in an industrial single feed fed-batch process applicable at small scale as well as in bioreactor s. Cell culture experiments were carried out either in spin tubes or bioreactors with a CHO suspension cell line expressing a human monoclonal antibody. Viable cell density and viability were measured using an automatic cell counting device. Spent media analysis of supernatants was carried out for amino acids after pre-column derivatization and UPLC analysis and for vitamins using LC-MS/MS. Metabolite measurements were performed with Cedex Bio HT relying on photometric and turbidometric methods. Characterizati on of the monoclonal antibody was performed using 2-AB labeling for glycan analyses, cIEF for charge variants analyses and LC-MS/MS for peptide mapping experiments. Stability studies of the feed containing the modified cysteine derivative showed that the molecule was stable and that no L-cysteine or L-cystine was released over three months when stored at room temperature or 4 ° C. Moreover, no change in the color of the feed was observed over time. Small scale batch experiments where L-cysteine was replaced by the same amount of chemically modified cysteine indicated no change in growth or viability profiles. Use of the modified cysteine derivative in small scale fed-batch processes indicated comparable maximum viable cell density, prolonged viability and increased titer compared to the established two feed system. Bioreactor experiments confirmed the increase in specific productivity described at small scale when the single feed strategy was compared to the two feed strategy. In depth characterization of the monoclonal antibody indicated no change in the glycosylation or charge variant pattern whereas peptide mapping experiments were not able to detect any integration of the modified amino acid in the sequence of the monoclonal antibody.
Professor & Chair of Mechanical Engineering, York University Canada
Time : 10:30-11:00
Sushanta Mitra is a Kaneff Professor in Micro & Nanotechnology for Social Innovation at the York University, Toronto. His research interests are in the fundamental understanding of fluid flow in narrow confinements and its applications in the fields of energy, environment and bio-systems. For his contribution in science and engineering, he has been an elected fellow of the American Society of Mechanical Engineers, the Canadian Society for Mechanical Engineering, the Engineering Institute of Canada, the Canadian Academy of Engineering and the Royal Society of Chemistry.
In recent years there is a significant development in micro and nanotechnology that has enabled fabrication of fine micro/nanostructures, which are often used as building-block towards producing sensors which are specific, selective and sensitive towards number of key biomolecules. The talk will focus on how such micro/nanofabrication tools coupled with fundamental developments in physics and chemistry can create next generation sensors that can be used for monitoring deadly virus like Dengue NS1, food borne pathogen like Listeria monocytogenes, water borne pathogens like E. coli and cardiac markers like myoglobin for early diagnostics of heart attack. The talk will end with example of a translational and transformative research which allows the laboratory proto-type to be tested in field and end-user communities.