Russell, Athena L

BACKGROUND Expanding quantities of mesenchymal stem cells (MSCs) sufficient to treat large numbers of patients in cellular therapy and regenerative medicine clinical trials is an ongoing challenge for cell manufacturing facilities. STUDY DESIGN AND METHODS We evaluated options for scaling up large quantities of bone marrow–derived MSCs (BM‐MSCs) using methods that can be performed in compliance with Good Manufacturing Practices (GMP). We expanded BM‐MSCs from fresh marrow aspirate in αMEM supplemented with 5% human platelet lysate using both an automated cell expansion system (Quantum, Terumo BCT) and a manual flask‐based method using multilayer flasks. We compared MSCs expanded using both methods and assessed their differentiation to adipogenic and osteogenic tissue, capacity to suppress T‐cell proliferation, cytokines, and growth factor secretion profile and cost‐effectiveness of manufacturing enough BM‐MSCs to administer a single dose of 100 × 10 6 cells per subject in a clinical trial of 100 subjects. RESULTS We have established that large quantities of clinical‐grade BM‐MSCs manufactured with an automated hollow‐fiber bioreactor were phenotypically (CD73, CD90, CD105) and functionally (adipogenic and osteogenic differentiation and cytokine and growth factor secretion) similar to manually expanded BM‐MSCs. In addition, MSC manufacturing costs significantly less and required less time and effort when using the Quantum automated cell expansion system over the manual multilayer flasks method. CONCLUSION MSCs manufactured by an automated bioreactor are physically and functionally equivalent to the MSCs manufactured by the manual flask method and have met the standards required for clinical application.

BACKGROUNDClinical trials involving mesenchymal stem cell (MSC) therapy have variable outcomes. We hypothesize this is largely attributed to donor‐to‐donor variability and tissue of origin.STUDY DESIGN AND METHODSWe examined proliferation rates, cytokine secretion profiles, and differentiation capability of seven bone marrow–derived MSCs (BM‐MSCs) and 16 adipose tissue–derived MSCs (AD‐MSCs) from 23 donors.RESULTSAD‐MSCs had the capacity to undergo more than 40 population doublings, while the BM‐MSC proliferation rate was found to be considerably slower. We observed more donor‐to‐donor variability in proliferation rates of BM‐MSCs than with AD‐MSCs. Cytokine analysis revealed that secretion of eight cytokines was significantly increased by AD‐MSCs at Passage (P)3 compared with P1, while for BM‐MSCs at P3 relative to P1, only interleukin‐8 and RANTES secretion was significantly increased. By P5, secretion of all cytokines by AD‐MSCs was either decreased or unchanged relative to P1. In contrast, cytokine secretion by BM‐MSCs at P5 was mostly unchanged, although secretion of six cytokines was significantly increased relative to P1. When we compared cytokine secretion between AD‐MSCs and BM‐MSCs at P3, AD‐MSCs significantly secreted higher concentrations of cytokines than BM‐MSCs while the opposite was observed at P5. This suggests that BM‐MSCs are relatively more potent at P5 while AD‐MSCs are relatively more potent at P3. AD‐MSCs and BM‐MSCs exhibited the capacity for chondrogenic differentiation. AD‐MSCs and BM‐MSCs appeared to display a more enhanced inclination toward adipogenic and osteogenic differentiation, respectively.CONCLUSIONMSC physiology is significantly influenced by donor variability and tissue of origin and this should be considered when designing clinical trials.