EXPERIMENTAL DESIGN AND SMALL-SCALE MODEL FOR HIGH-PERFORMING PERFUSION MEDIA AND PROCESSES SCALABLE TO 50 L BIOREACTORS

摘要

Cell culture perfusion processes are considered optimal for a truly integrated continuous biomanufacturing pipeline. The nutrient-rich but balanced media should be designed to support very low cell-specific perfusion rates (CSPR) that minimize media consumption but maximize viable cell days and productivities. Optimized processes at low CSPR drastically reduce equipment costs, lab space, and product dilution. Finally, operating at very low CSPR enables running mammalian cell bioprocesses as true chemostat cultures in the future. We demonstrate a general workflow to develop high-performing perfusion media using small-scale models and transferred the process to 50 L scale at CSPR of 20 pL/c/d. Recombinant CHO cells were evaluated at small scale in shaking tubes. Cells were grown in HyClone™ ActiPro or CDM4NS0 basal media, and optimal spike concentrations of HyClone Cell Boost™ supplements were determined using a DoE-supported workflow. The identified high-performing perfusion medium was applied to ReadyToProcess WAVE™ 25 and XDR-50 bioreactor runs. Different strategies were tested to find the critical minimum CSPR and maximum supported viable cell density (VCD). The obtained product profile was compared between scales, as determined by glycan-, charge-, and size-variant distribution. Scale-down models were leveraged to define high-performing media and applied to bioreactor runs at constant volumetric perfusion rate, VCD, or CSPR. CSPR values as low as 10 pL/c/d at 2 × 10~8 c/mL were achieved. These results make high-density perfusion processes suitable for inoculum preparation (N-1) or high cell density cryopreservation. The developed perfusion processes supported steady-state production at constant 5 × 10~7 c/mL by applying a continuous cell bleed and were scaled to 50 L.