Impact of single-use bioreactor bag materials on Spodoptera frugiperda cell expansion for recombinant adeno-associated virus manufacturing.

Recombinant adeno-associated virus production for gene therapy applications commonly relies on the Spodoptera frugiperda 9 (Sf9) baculovirus infection platform. The process encompasses cell expansion from flasks through intermediate-scale bioreactors to large-scale production. A critical challenge in this process is suboptimal cell proliferation during the expansion phase, which significantly impacts subsequent virus production. This study evaluates the effects of different single-use bioreactor bags on Sf9 cell growth, focusing on two potential issues: incompatibility between Sf9 cells and bag materials, and the presence of leachables and extractables from the bag. Single-use rocking motion bioreactor bag configuration, including material- and surface-related attributes, was associated with substantial differences in Sf9 cell expansion performance. While growth kinetics in shake flasks and the Pall Allegro XRS system were comparable, reduced growth rates and delayed proliferation were observed in Cytiva Cellbags. The comparable growth observed in shake flasks and the Pall XRS system, together with the lack of recovery after rocking-parameter adjustments in Cellbags, suggests that bag-associated material and surface-related factors, rather than rocking motion alone, contributed substantially to the observed growth differences. Lower bag occupancy further exacerbated growth inhibition. Washing studies showed no improvement in new bags, whereas partial recovery after initial use suggested transient bag conditioning or surface-related effects. Analytical extractables and leachables profiling was not performed; therefore, leachable-mediated contributions cannot be fully excluded. These findings highlight the importance of single-use bag selection and occupancy optimization for robust and scalable Sf9 cell expansion processes.