A Novel, Single-Use Bioreactor System for Expansion of Human Mesenchymal Stem/Stromal Cells

Background & Aim There is a significant need for efficient systems that can be used to generate primary cells and stem cells which can be readily implemented in research labs and expedite process development studies, pre-clinical testing, and large-scale expansion. Although various platforms for expansion of sufficient cell numbers exist, these systems are rarely comprehensive enough to allow for rapid implementation by researchers. These systems are also not easy to use nor are they robust enough to reproducibly supply high quality cells. A complete system for the generation of sufficient cell numbers that utilizes a bioreactor platform which is robust and easy-to-use is therefore highly desirable. Methods, Results & Conclusion We have previously demonstrated efficient expansion of human mesenchymal stem/stromal (hMSC) in the PadReactor® single-use bioreactor system to the 40 L scale. This system utilized commercially-available, well-characterized cells, specially-formulated growth media and supplements, SoloHill microcarriers, and a single-use bioreactor platform that could be used to generate tens of billions of cells within 7 days of culture. Here we extend these finding by employing these components in a novel bioreactor type which contains a bottom-mounted impellor. The Allegro™ STR bioreactor is a new single-use stirred tank bioreactor platform which is scalable, compact, ergonomic, and designed to maximize usability and process assurance. hMSC and medium were cultured at 30 L scale in microcarrier-based, fed-batch cultures in the Allegro STR bioreactor for 5 days. Cells harvested from microcarriers retained critical quality attributes when examined in standard cell characterization assays. The results obtained in this study lay the groundwork for a complete system for efficient generation of high quality cells for process development studies and future large scale cell expansion. Together, the Allegro STR bioreactor and the SoloHill microcarriers provide a practical manufacturing solution for large-scale expansion of adherent cells.