[In vitro studies about the effects of implanted materials on osteocalcin and alkaline phosphatase of rat osteoblasts].

OBJECTIVE: To evaluate the effects of the four implant materials, hydroxyl poly calcium sodium phosphate (HPA), hydroxyapatite (HA), bioglass ceramics (BGC) and titanium (Ti) on osteocalcin secreting amount and alkaline phosphatase activity of rat osteoblasts cultured in vitro, and expose the biological compatibility conditions of the implant materials as well as the index to estimate cytocompatibility. METHODS: The powders of HPA, HA, BGC and Ti were sterilized and made into extracted solutions with 199 culture medium, and the isolated osteoblasts which were taken from three-day-old Sprague-Dawley rats' calvaria, were incubated in 199 culture medium too. Then the osteoblasts were mixed and incubated into the four kinds of extracted solutions of the implant materials. After eight days of co-incubation, the cells were taken out to measure alkaline phosphatase activity with velocity analysis, and the extracellular liquid was used to estimate osteocalcin secreting amount with radioisotope analysis. RESULTS: 1. Osteocalcin secreting amount of the osteoblasts co-incubated with HPA, HA, BGC were as normal as the control, while that of other cells co-incubated with titanium was reduced (P < 0.05). 2. Alkaline phosphatase activities of all the co-incubated osteoblasts were as normal as the control. CONCLUSION: The osteocalcin secreting amount and alkaline phosphatase activity can reflect the biological compatibility of implant materials, and they may be used as indexes to evaluate biological compatibility condition of implant materials.