Phenotypic and Functional Equivalency of Digested Bone Marrow Mesenchymal Stem Cells to Aspirated Bone Marrow Mesenchymal Stem Cells
Authors: Miller Hannah Marie , Gu Dongsheng , Johnstone Brian , Sherry Aubrey , LaFontaine Michael , Woods Erik 
Published: June 2021

Adult mesenchymal stem cells (MSCs) are found throughout the body, including in the dental pulp, adipose tissue, and bone marrow (BM), among other tissues. MSCs are receiving increased attention in the medical field due to their therapeutic and regenerative effects. However, since MSCs comprise only 0.01–0.001% of BM cells, traditional methods of living donor aspiration yield a few hundred to a few thousand cells which must be extensively expanded to obtain a clinically significant number of transplantable cells. Results from late‐stage clinical trials suggest that MSC lose functional potency with expansion; thus, there is a need for large sources of primary MSCs for therapeutic use. BM from deceased donors are a potential source of large quantities of unpassaged MSCs. However, the functional equivalency of deceased donor‐ to living donor‐derived MSC has not been previously established. This study compared phenotypic and functional properties of enzymatically digested MSCs from deceased donor vertebral bodies (VBs) to MSCs obtained from aspirates of living BM.MSCs isolated from living and deceased donors were characterized according to the International Society for Cellular Therapy (ISCT)‐criteria. VBs obtained under IRB approval from five deceased organ donors were ground and filtered to extract BM. The remaining cortical and trabecular bone fragments were digested using a mix of collagenase and neutral protease (DE10, Vitacyte, Indianapolis, IN) to obtain MSCs. Digested and whole BM mononuclear cells were then plated on uncoated plastic and plastic‐adherent MSCs were expanded through four passages. Three different aspirated BM MSC samples from LaCell, L.L.C. were used as live donor controls and were expanded through three passages. MSCs were characterized at each passage for adipogenic, chondrogenic, and osteogenic differentiation potential, CFU‐F, population doubling time, and flow cytometry.Both living aspirate and deceased digest MSCs showed fibroblast‐like phenotypes at each passage during expansion. Both also differentiated into adipocytes, chondrocytes, and osteocytes. Flow cytometry revealed both living aspirate and deceased digest samples were negative for CD14, CD19, CD34, CD45, and HLA‐DR and were positive for CD73, CD90, and CD105. There was no significant difference in viability between LaCell's aspirated sample and MSCs from digested VBs. Both living and deceased donor derived MSCs were capable of forming colonies further demonstrating their equivalency.The results of these experiments show that deceased donor digested MSCs are comparable to living donor aspirated MSCs in their phenotype, tri‐lineage differentiation capacity, viability, and cell surface markers. Additionally, deceased donor digested MSCs are superior to living donor MSCs in their less intrusive recovery procedures and greater potential yield, given that there are no restrictions on the amount of BM harvested to reduce donor morbidity.Support or Funding InformationResearch was supported by:A grant by the National Institutes of Health (NIAID Grant No. 1 U01 AI138334‐01)Ossium Health, IncMarian College of Osteopathic MedicineThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.