Evaluation of a novel pneumatic bioreactor system for culture of recombinant Chinese hamster ovary cells

Single use culture systems are a tool in research and biotechnology manufacturing processes and are employed in mammalian cell-based manufacturing processes. Recently, we characterized a novel bioreactor system developed by PBS Biotech. The Pneumatic Bioreactor System (TM) (PBS) employs the Air-wheel (TM), which is a mixing device similar in structure to a water wheel but is driven by the buoyant force of gas bubbles. In this study, we investigated the physical properties of the PBS system, with which we performed biological tests. In 2 L PBS, the mixing times ranged from 6 (30 rpm, 0.175 vvm) to 15 sec (10 rpm, 0.025 vvm). The k(L)a value reached upto 7.66/h at 0.5 vvm, even without a microsparger, though this condition is not applicable for cell cultures. Also, when a 10 L PBS equipped with a microsparger was evaluated, a k(L)a value of upto approximately 20/h was obtained particularly in mild cell culture conditions. We performed cultivation of Chinese hamster ovary (CHO) cells in 2 and 10 L PBS prototypes. Results from the PBS were compared with those from an Erlenmeyer flask and conventional stirred tank type bioreactor (STR). The maximum cell density of 10.6 x 106 cells/mL obtained fromthe 2 L PBSwas about 2 times higher than that from the Erlenmeyer flask (5.6 x 10(6) cells/mL) andwas similar to the STR (9.7 x 10(6) cells/mL) when the CHO-S cells were cultured. These results support the general suitability of the PBS system using pneumatic mixing for suspension cell cultivation as a novel single-use bioreactor system.