New Cryopreservation Technology of hMSCs: First Preclinical Results Using DMSO-containing Medium.

BACKGROUND Human mesenchymal stem cells (hMSCs) have tremendous potential in regenerative medicine, making it desirable to cryopreserve and bank them to increase their access and availability. OBJECTIVE This research is part of a clinical trial performed on six patients that aimed to use advanced therapy medicinal products (ATMPs) based on hMSCs in patients undergoing repeated total hip replacement. MATERIALS AND METHODS To compare the characteristics of fresh and frozen hMSCs, we used the trypan blue exclusion test (cell viability), flow cytometry (cell viability and phenotyping), sterility determinations and the clonogenic assay of cell proliferation. RESULTS Cryopreserved hMSCs showed good quality parameters after thawing in comparison with fresh hMSCs in suspension. When using a medium containing dimethyl sulfoxide (DMSO), the viability was higher than 90% in all cases. The cell purity determined by flow cytometry was also acceptable. CONCLUSION These initial results show that the prepared cryopreserved ATMP exhibited good viability and phenotype characteristics.