Comprehensive study on Wave bioreactor system to scale up the cultivation of and recombinant protein expression in baculovirus-infected insect cells

Abstract

Although the baculovirus expression vector system has been widely used to produce a variety of recombinant proteins, the shear sensitivity of insect cells besides their relatively high oxygen uptake rates have limited their large scale applicability. To address such issues, Wave bioreactor systems have been developed to provide the insect cells with sufficient dissolved oxygen in a bubble free medium of minimal shear stress. However, selection of rocking parameters, and the methods used to control the processes have not been well described in literature. Herein, oxygen transfer capacity of Wave bioreactor has been investigated at different combinations of rocking parameters. Considering the specific oxygen uptake rates (SOUR) and the assessed oxygen transfer capacity of the Wave bioreactor, rocking parameters were set to cultivate non-infected Spodoptera frugiperda 9 cells and infected/non-infected BTI-TN-5B1-4 cells in 2 L Cellbags. The obtained results were exploited to estimate the SOUR of the insect cells under actual condition of Wave bioreactor system. Furthermore, although Express Five medium was recommended by the supplier, the yield of the active soluble human papillomavirus (HPV) 16L1 protein expression was improved in Sf900 II medium. Using the obtained results, protein expression in BTI-TN-5B1-4 cells was finally scaled up to 50 L confirming that the obtained information could be successfully used to scale the Wave bioreactor by specifying the rocking parameters.