2013 年 11 巻 2 号 p. 103-112
An important element of treatment for Cleft lip/cleft palate is the attainment of normal occlusion. We recultured human bone tissue-derived mesenchymal stromal cells (hBT-MSCs) in vitro following cryopreservation for ≥10 years, divided the cells into osteogenic differentiation and nondifferentiation MSC groups, and compared the cells in the two groups. In vitro expression of osteoblast markers was then measured. Furthermore, we created a hybrid-type bone substitute and transplanted it into the skulls of 8-week-old male nude rats. Eight weeks later, the skulls were examined by Micro CT. We then performed microscopic analysis of grafts after hematoxylin and eosin (HE) staining and calculated the surface ratio. Immunohistochemical staining with an anti-human osteocalcin antibody was also performed and NEO STEM™ expression was confirmed by fluorescence microscopy. With regard to osteoblast marker expression, alkaline phosphatase and osterix were significantly elevated in the osteogenic differentiation MSC group (P < 0.05). Micro CT revealed osteogenesis in the hybrid-type bone substitute grafts. HE staining clearly indicated new bone formation within porous hydroxyapatite in the hybrid-type bone substitute grafts. Immunohistochemical staining indicated anti-human osteocalcin antibody expression and NEO STEM™ expression in the sites exhibiting new bone formation. The volume of bone formation was also significantly higher in the osteogenic differentiation MSC group than in the nondifferentiation MSC group (P < 0.05). We observed excellent osteogenic capability of hBT-MSCs following cryopreservation for ≥10 years, and we believe that our hybrid-type bone substitute can be adapted for future clinical application.