Enhancement of human osteoblast proliferation and phenotypic expression when cultured in human serum

Traditionally, culture medium is supplemented with foetal bovine serum (FBS ). However, in cultures of osteoblasts intended for human re-implantation, such serum presents potential risks of foreign protein contamination and tr ansmission of viral or prion-related material, if used. We cultured human o steoblasts from 16 patients in 10% autologous human serum, 10% pooled human serum, 10% FBS or 2% Ultroser G. Non-synthetic sera were tested in both he at-treated and non-heat-treated forms. We determined cell growth and osteob last phenotype. Cell proliferation in all types of human serum was signific antly greater than in FBS. This was most marked in heat-treated autologous human serum. Cells cultured in Ultroser G had less proliferation than all o ther groups. The phenotypic tests showed that cells cultured in human and f oetal bovine serum displayed an osteoblast phenotype, with greater protein expression in cells cultured in human serum. We conclude that culture of human osteoblasts; in autologous human serum en hances cell proliferation, while maintaining an osteoblast phenotype. These findings have implications for the use of cultured osteoblasts in self-cel l therapy. Human osteoblast growth is supported by autologous human serum, which allows re-implantation of cultured cells, while avoiding the risk of foreign protein carry-over with enhancement of cell proliferation.