Takuya Kubo is an Associate Professor of Department of Material Chemistry, Graduate School of Engineering, Kyoto University. He received his PhD from Kyoto Institute of Technology in 2004. He joined the Graduate School of Environmental Studies, Tohoku University as an Assistant Professor (2004–2012) and worked at Department of Chemistry, Portland State University as a Visiting Professor (2010). He joined the Graduate School of Engineering, Kyoto University as an Associate Professor (2012). His research interests include the development of novel materials having molecular recognition ability for selective separation and functional porous materials for novel separation media.
A variety of antibody-based medicines have been approved in recent years. These products have high annual returns due to their high selectivity toward their target antigens, relatively low levels of side effects, and stability in vivo; in addition, these medicines can be produced using standard cell culture procedures. To obtain a high-quality antibody medicine at low cost, it is necessary to select highly productive cells, optimize the culture conditions, and develop an efficient purification method. To evaluate the productivity of a system for biosynthesis of an antibody, especially of the immunoglobulin G (IgG) subtype, Protein A–immobilized chromatography is often employed for selection and optimization of the cell culture. In order to process a large number of samples, it is necessary to perform rapid optimization using high-throughput chromatography. However, for currently available separation media, elution throughput is often limited, resulting in inefficient optimization of purification and productivity. Therefore, there is an urgent demand for new separation media that could facilitate higher throughput and lower cost. In this study, we developed a spongy-like porous polymer (spongy monolith) consisting of poly (ethylene-co-glycidyl methacrylate) with continuous macropores that allowed efficient in situ reaction between the epoxy groups and proteins of interest. Immobilization of Protein A on spongy monolith enabled high-yield collection of immunoglobulin G (IgG) from cell culture supernatant even at high flow rate. In addition, immobilization of pepsin on spongy monolith enabled efficient online digestion at high flow rate. We believe that this new platform will be useful for variety of protein-based reactions with rapid flow rates and low costs. Additionally, the platform can be easily scaled up, and we anticipate that future efforts will contribute to purification of antibody-based medicines including biosimilars at the plant level.
Developing an optimal cell culture media, combined with a robust high-throughput analytical method to monitor the influence of nutrient feed and their metabolites on the productivity of the cell culture and the desired product quality are as essential as engineering an effective expression system or choosing a good host cell line. Information gained from the high-throughput cell culture profiling analytical method could help to establish the intricate balance of the intracellular and extracellular metabolites and subsequently used to drive modification to the nutrient feed and cell culture process to optimize yield or target specific product attributes during production of biopharmaceuticals such as therapeutic antibodies. In this study, we demonstrate a high-throughput LC-MS/MS method for the simultaneous analysis of 95 components in cell culture media at a rate of 17 minutes per sample. The method targets sugars, amino acids, vitamins, nucleic acid associated substances, organic acids etc. To our best knowledge, the method represents the highest number of cell culture media components and their secreted metabolites analyzed simultaneously in a single analysis.