Human marrow cells-derived cultured bone in porous ceramics.

From four patients (mean age, 60 years; range 51-76 years), 3 ml of bone marrow was collected from the ilium. The marrow was cultured to concentrate and expand the marrow mesenchymal cells on a culture dish. The cultured cells were then subcultured either on another culture dish or in porous areas of hydroxyapatite ceramics in the presence of dexamethasone and beta-glycerophosphate (osteogenic medium). The subcultured tissues on the dishes were analyzed by scanning electron microscopy (SEM), and subcultured tissues in the ceramics were implanted intraperitoneally into athymic nude mice. Vigorous growth of spindle-shaped cells and a marked formation of bone matrix beneath the cell layers was observed on the subculture dishes by SEM. The intraperitoneally implanted ceramics with cultured tissues revealed thick layer of lamellar bone together with active osteoblasts lining in many pore areas of the ceramics after 2 months. The in vitro bone formation on the culture dishes and in vivo bone formation in porous ceramics were detected in all cases. These results indicate that we can assemble an in vitro bone/ceramic construct, and due to the porous framework of the ceramic, the construct has osteogenic potential similar to that of autologous cancellous bone. A significant benefit of this method is that the construct can be made with only a small amount of aspirated marrow cells from aged patients with little host morbidity.