3D MSC Culture in Saint-Gobain VueLife® FEP Bags Using Microcarriers

Abstract

Background & Aim MSCs are anchorage-dependent cells that require interaction with a substrate for cell survival and active proliferation. Achieving clinically relevant autologous cell doses in vitro requires significant surface area. Microcarriers are a commonly used, high surface area 3D culture solution combined with traditional bioreactors for allogeneic therapies; however, bioreactors are operated at a much larger scale than that required for personalized medicine. Therefore, a solution combining mid-size, fully closed, single use bags from Saint-Gobain's VueLife® product line with commercially available microcarriers is promising for autologous scale expansion of MSCs. As demonstrated here, VueLife® FEP bags are particularly attractive for this application due to the inherent non-stick properties of the FEP, preventing cell and microcarrier adhesion to the bag surface. Methods, Results & Conclusion For this study, human bone marrow-derived MSCs were purchased from RoosterBio Inc. and cultured in RoosterNourish™ MSC-XF medium. To assess donor-dependent variability in the cell culture performance, three individual donors were compared. MSC expansion was performed in Saint-Gobain's VueLife® 32-C bags with Corning® CellBIND® polystyrene microcarriers and Corning® Synthemax™ II-coated dissolvable microcarriers. Protocols for MSC attachment, expansion and harvest were developed for both microcarrier systems. Cell expansion results after 6 days of culture using the microcarriers are summarized in Tables 1+2. Strong donor-dependent variability was observed in the outcome, with expansion results ranging from 4- to 21-fold increase. However, because the CellBIND® beads are not transparent, cell attachment and harvest efficiency cannot be easily tracked by microscopy and may have also impacted the outcome. Cell attachment and expansion was easier to observe on the dissolvable microcarriers, with clear attachment after four hours and full confluence after four days of culture (Figure 1). MSCs showed 24-26-fold expansion for the three donors (Table 2) using the Corning® dissolvable microcarriers. MSC surface marker expression levels were not affected by culture on either microcarrier system in VueLife® bags and comparable to expression in T-175 flasks, as shown by flow cytometry. To support further expansion towards clinically-relevant doses, additional beads and media may be added to the bags. In summary, MSC expansion can be facilitated using microcarriers in VueLife® FEP bags for patient specific therapies. Results of MSC expansion on Corning's CellBIND® and Synthemax™ II-coated microcarriers after 6 days in culture in Saint-Gobain VueLife® 32-C bags. Results are shown for three tested MSC donors (#164, #172 and #227).