SCALABLE AND AFFORDABLE MANUFACTURE OF THERAPEUTIC MESENCHYMAL STROMAL CELL PRODUCTS ON CUSTOMIZABLE, DEGRADABLE MICROCARRIERS

• Published in: Cytotherapy (Oxford, England) England), 2024-06, Vol.26 (6), p.e2-e2
• Main Authors: Haskell, A., White, B.P., Rogers, R.E., Gobel, E., Lopez, M.G., Syvyk, A.E., de Oliveira, D.A., Barreda, H., Benton, J., Benavides, O.R., Dalal, S., Bae, E., Zhang, Y., Maitland, K., Nikolov, Z., Liu, F., Lee, R., Kaunas, R., Gregory, C.A.
• Format: Article
• Language: English
• Subjects: Degradable microcarriers; MSC therapy; Scalable manufacture
• ISSN: 1465-3249; 1477-2566
• DOI: 10.1016/j.jcyt.2024.04.011

Human mesenchymal stromal cells (hMSCs) and their secreted products have been demonstrated to have remarkable clinical utility in the treatment of musculoskeletal trauma and various inflammatory diseases. Despite decades of attempts to make hMSC products available for clinical use, current manufacturing methods do not permit cost-effective, scalable manufacture. We previously described the scalable fabrication of customizable, degradable microcarriers comprised of gelatin methacryloyl (GelMA) that could be used to culture induced pluripotent stem cell-derived hMSCs (ihMSCs) and other adherent cells. This study demonstrates that GelMA microcarrier (GelMA-M) culture can be scaled to produce clinically relevant quantities of hMSCs. The ihMSC products generated from GelMA-M culture exhibit enhanced osteogenic and immunomodulatory characteristics compared to monolayer cultures while providing a substantial cost benefit over monolayer or polystyrene microcarrier cultures. We cultured ihMSCs in 500 mL and 3 L vertical wheel bioreactors on GelMA-M and polystyrene microcarriers for 8 days. Cell counts every two days demonstrate that at larger scales, GelMA-M cultures proliferate faster than polystyrene or monolayer cultures and exceeded cell densities we previously considered to be overconfluent. Fluorescent microscopy revealed cells attached to multiple microcarriers, suggesting that the aggregates formed during the second half of the culture unlock additional surface area of the substrate, which is corroborated by retained osteogenic and adipogenic differentiation potential. When used to treat a critical murine calvarial defect, osteogenic cell matrix extracted from GelMA-M ihMSCs enhanced bone regeneration beyond that seen in monolayer cultures to an extent comparable to bone morphogenic protein-2 (BMP-2), absent bony growths we observed and are commonly reported in BMP-2. In a standard murine peritonitis assay, ihMSCs cultured on GelMA-M reduced neutrophil infiltration and expression of TNFα, IL-6, CXCL1, and CXCL2, indicating an immunomodulatory effect that exceeded monolayer cultures. Finally, our cost analysis predicts that GelMA-M culture will reduce the manufacturing cost of ihMSCs by 35% over monolayer cultures and 6.8% over polystyrene while providing benefits in customization and ease of harvesting.