714. Use of a Modular Workstation for Reduced Biosafety Risks Also Increased Cellular Yields

Abstract

Cell culture processing in a room-air biologic safety cabinet (BSC), even in a cleanroom, creates multiple risks for both cell cultures and users. Humans can be exposed to genetically-modified cells, viruses, and other biological hazards during suboptimal (open) cell handling in a room air BSC. The cell cultures can also be exposed to suboptimal separation of air during cell handling in the BSC which creates a contamination hazard. In addition, even in the cleanest clean room, cells are exposed to room air temperatures and gas levels. Until cells re-equilibrate with the incubator after handling, cells are chilled, hyperoxic, and hypocapnic compared to physiologic conditions. A barrier isolator (closed cell processing workstation) creates a constant physical barrier between cells and users. This barrier reduces the risks of air mixing between cells and people without dependence upon laminar air flow in a BSC or a costly whole-room HVAC system. We undertook the following study to test the hypothesis that the use of a barrier isolator, during cell handling as well as incubation, could improve cell growth by providing unbroken physiologic conditions to cells. We used K562 cells, an undifferentiated leukemic cell line that has been used for T cell bioprocess optimization. We divided a single culture into two sets of triplicate cultures in T-75 flasks, three for growth in a barrier isolator and three for growth in a standard room-air incubator equipped with an inner chamber (C-chamber) for control of gasses. Both sets of cultures were incubated at 5%CO2, 5%O2, 37 C, and tracked for cell growth and viability over two weeks. For routine subculturing twice weekly, the cultures in the isolator were handled in the processing chamber of the isolator in physiologic conditions identical to the incubator. The cultures in the room-air incubator and C-chamber were handled in a standard room-air BSC (open). While cell viability was high in both sets of cultures, we found that handling cells under continuous physiologic conditions produced statistically higher cell yields over time (p=0.00086, Day 14, two-tailed paired T test, assuming unequal variances). No contamination events occurred and particle count data indicated no breach of functional separation between room air and isolator cell culture workspace. We concluded that cell handling in unbroken physiologically relevant conditions produced better cell growth over time while reducing risks to both cells and cell culturists. We predict that as cells become increasingly valuable, controlled workspaces for better cell growth and lower biosafety risks will become increasingly valuable as a part of a total quality approach to cell culture.