Osteogenic potential of cryopreserved human bone marrow-derived mesenchymal stem cells cultured with autologous serum.

Secondary bone grafting in the alveolar cleft is one of the most important therapeutic modalities for patients with cleft lip and palate. However, in children, harvesting a sufficient amount of bone is difficult, and repeated operations are often required because deformation of the alveolar cleft may occur because of the grafted bone absorption and bone growth, which imposes a heavy burden on the patients. The burden may be reduced if the banking of human bone marrow-derived mesenchymal stem cells (MSCs) could be made possible, that is, if cryopreserved autologous MSCs, those that have been harvested from the patient's own bone marrow, could be cultured and expanded with the patient's own serum and can be thawed and cultivated for grafting at a later date. In the current study, a hybrid-type bone substitute was prepared by thawing and cultivating MSCs that have been cryopreserved for more than 3 months. The hybrid-type bone substitute was implanted subcutaneously in nude mice. At 6 and 9 weeks after grafting, the bone graft was removed, and the osteogenic potential of the cells cultured with autologous serum, as determined by alkaline phosphatase activity and alizarin red S staining, was compared with those cultured with fetal bovine serum. There was no significant difference in the osteogenic potential between MSCs cultured with autologous serum and those cultured with fetal bovine serum. The results suggest the possibility of artificial bone grafting using MSCs cultured with autologous serum and the banking of the cells.