Scaling‐up of an Insect Cell‐based Virus Production Process in a Novel Single‐use Bioreactor with Flexible Agitation

A novel single-use bioreactor was recently introduced to the market that is agitated by impellers suspended on flexible ropes rather than a rigid shaft. Computational fluid dynamics (CFD) models were created and validated by particle image velocimetry (PIV) to predict the bioreactor’s fluid flow and mixing. The data were then used to scale-up a Spodoptera frugiperda, subclone 9 (Sf9) insect cell-based production of recombinant adeno-associated virus (AAV) from a benchtop glass bioreactor to the single-use system with 30 L working volume. This viral vector is one of the most commonly used in gene therapies. The volumetric power input was kept constant while maintaining reasonable mixing times and shear stresses between the scales. Peak cell densities of up to 7.2·10^6 cells/mL and maximum virus titers of 1.7·10^11vg/mL were achieved. Similar cell growth and metabolite profiles further proved the successful process transfer between the two geometrically non-similar bioreactor systems. The pilot bioreactor yielded between 3.3 and 4.8·10^15 vg that, depending on the therapy, can be sufficient for the treatment of a single patient.