Product sieving challenges in TFF perfusion cell culture
May 6-11, 2018
Integrated continuous biomanufacturing has gained significant interest because of its potential to streamline production by integrating upstream and downstream processes. Combined with an intensified perfusion bioreactor, continuous processing can greatly reduce cost, space requirements, and handling steps, while improving production efficiency.1,2 During perfusion operation, product and spent media are removed while cells are retained within the bioreactor with a cell separation device. In particular hollow fiber membranes, attached externally to the bioreactor, permit tangential or alternating flow filtration (TFF, ATF), as cells are recirculated through the unit and permeate is harvested for downstream processing.3,4 However, membrane fouling and issues with product sieving, especially associated with a TFF setup, have a direct impact on total product yield from the process, and can cause hollow fiber reliability issues which in some cases can result in premature termination of a bioreactor run. It is hypothesized that membrane fouling from host cell proteins, cell debris, or additives such as antifoam can result in decreased product sieving as product transmission through the membrane decreases over time.5,6 Toward addressing issues with product sieving, we aim to identify the underlying causes of membrane fouling, associated with host cell proteins and antifoam, and to develop new methods to lengthen their lifetime during perfusion operation. This presentation will focus on some tools and experiments that we have conducted to address this issue with the goal to identify factors within the bioreactor that lead to reduced product sieving and implementation of new strategies to mitigate the effects of these factors during operation. 1. Konstantinov, K.B., Cooney C.L “White Paper on Continuous Bioprocessing” Journal of Pharmaceutical Sciences 104 (3), 2015, 813-820. 2. Warikoo, V., et al. “Integrated Continuous Production of Recombinant Therapeutic Proteins” Biotechnology and Bioengineering 109 (12), 2012, 3018-3029. 3. Clinke, M.F., et al. “Very High Density of CHO Cells in Perfusion by ATF or TFF in WAVE Bioreactor. Part I.” Biotechnology Progress 29 (3), 2013, 754-767. 4. Karst, D.J., et al. “Characterization and Comparison of ATF and TFF in Stirred Bioreactors for Continuous Mammalian Cell Culture Processes” Biochemical Engineering Journal 110, 2016, 17-26. 5. Van Reis, R., Zydney, A. “Bioprocess Membrane Technology” Journal of Membrane Science 297, 2007, 16-50. 6. Wang, S., et al. “Shear Contributions to Cell Culture Performance and Product Recovery in ATF and TFF Perfusion Systems” Journal of Biotechnology 246, 2017, 52-60.
Marcella Yu, Lisa Sawick, Henry Lin, Todd Luman, Jonathan Coffman, Scott Godfrey, Felipe Strefling, Hayden Tessman, and Daisie Ogawa, "Product sieving challenges in TFF perfusion cell culture" in "Cell Culture Engineering XVI", A. Robinson, PhD, Tulane University R. Venkat, PhD, MedImmune E. Schaefer, ScD, J&J Janssen Eds, ECI Symposium Series, (2018). http://dc.engconfintl.org/ccexvi/82