Stem Cell-Derived Matrices Provide Improved Isolation and Maintenance of hMSC Characteristics

Adult human mesenchymal stem cells (hMSCs) have shown promise as a valuable new therapeutic tool in a wide range of diseases. hMSCs from bone marrow stroma are currently isolated by their adherence to tissue culture treated polystyrene (TCP) and passaged multiple times on the same plastics until they are able to produce enough cells to be useful for research or clinical therapeutic trials. However, evidence in the literature has shown that culture on TCP can negatively alter hMSC function. Our aim was to expand hMSCs in an in vitro environment more closely resembling that of the hMSCs' native microenvironment to maximize proliferation while retaining therapeutic potential. We used decellularized hMSC-derived extracellular matrix (hMSC-ECM) to test hMSCs' maintenance of stem cell properties during in vitro expansion. We found that hMSC-ECM was able to increase hMSC proliferation while retaining the stem cells‘ immature state and increasing differentiation potential. In addition, the hMSC-ECM could be covalently cross-linked to polymer substrates and was effective in the isolation and expansion of hMSCs in the presence of fetal bovine serum and human serum. Using proteomics and transcriptomics, we were able to determine the mechanism behind the hMSCs’ increased proliferation was due to their ability to downregulate their otherwise required gene expression for ECM proteins by on hMSC-ECM. The effects of hMSC-ECM were largely hMSC specific and were not found with several other types of human cells. Providing a pre-formed in vitro niche for hMSCs can provide the cells with the critical components required for hMSC function during in vitro expansion. Three replicates of hMSC cells cultured on Tissue Culture Plastic Alone, Tissue Culture Plastic plus Crosslinker, hMSC Depositied ECM plus Crosslinker, hMSC Depositied ECM Plus Crosslinker and Fibronectin or hMSC Depositied ECM alone.