Osteogenic potential of cryopreserved human bone marrow-derived mesenchymal cells after thawing in culture

Cryopreserved human bone marrow-derived mesenchymal cells (hBMCs) were thawed and replated in culture dishes. Viability of the cells immediately after thawing was 98%. When the cells were cultured in the presence or absence of dexamethasone, the cells proliferated to reach confluency at culture day 7. The cells treated with dexamethasone formed abundant mineralized nodules at their extracellular regions after about culture day 14, while the cultures without dexamethasone did not exhibit bone formation. The calcein uptake into the extracellular matrix layer was detected in the dexamethasone-treated cells with the increase in fluorescent intensity with culture periods but not in the nontreated cells. These results suggest that human bone marrow-derived mesenchymal cells retain bone-forming capability even after cryopreservation/thawing.