Growth of osteoblasts on porous calcium phosphate ceramic: an in vitro model for biocompatibility study.

Biomaterial implantation in animals is commonly used for biocompatibility studies as well as examination of long-term interaction between tissue and the test material. An in vitro cell culture model is proposed as an alternative which will save animal lives and reduce the pain and discomfort of animals used for such studies. In this study the biomaterial was matched to the cell types typical of the implant site of the particular material: porous calcium phosphate ceramic, used as dental and orthopaedic implants, with periosteal fibroblasts, osteoblasts and chondrocytes. All three cell types attached on to the ceramic and formed multicellular layers. Numbers of periosteal fibroblasts, osteoblasts and chondrocytes increased 29-, 23- and 17-fold, respectively, during the 10 wk period. Osteoblasts retained their phenotypic expression by producing only Type I collagen. Parathyroid hormone (PTH, 50 nM) suppressed the alkaline phosphatase activity of osteoblasts by over 50% and increased cAMP by more than 10-fold over control cultures.