Evaluation and Characterization of Human Bone Marrow Mesenchymal Stromal Cells Cryopreserved in Animal Component-Free, Chemically Defined, Serum-Free Conditions

Abstract

Mesenchymal stromal cells (MSCs) have the potential to treat various disease indications and are the future of cell therapy-based regenerative medicine. Typically, MSCs cryopreserved in serum-containing freezing formulation are supplied at the clinical site, which necessities that this formulation is removed before the administration. This is a cumbersome process, and there is an immediate need for identifying serum-free, xeno-free cryopreservation medium that can be readily used. Here, we analysed two commercially available serum-free, xeno-free, defined freezing media viz., CryoStor 5 (CS5) and CryoStor 10 (CS10) on their effect on human bone marrow MSCs at different freezing cell densities (5, 10, 12.5, 15 and 25 million cells per ml) over a period of 6 months and compared them to the in-house PlasmaLyte A (PLA)-based cryopreservation media. We found that the MSCs cryopreserved in CS5 and CS10 showed similar characteristics as compared with the in-house freezing media for the various parameters analysed including post-thaw recovery, viability, phenotypic marker expression, CFU-F ability and trilineage differentiation potential of the MSCs. Our results show that human MSC could be successfully cryopreserved using serum-free and xeno-free cryopreservation media and can be delivered to the bedside without any manipulations.