The synthetic pure hydroxyapatite(HA) have excellent biocompatibility and a little osseous inductivity, however, there are still some shortcomings such as the high de-gree of crystallibility and the quite stability of the structure. Strontium seemed to have the potential to change the biocompatibility and physicochemical characteristics of HA for implant use. Sr-HA containing 1%, 5%, 10%, 100% Sr2+ were synthesized by solution-reaction system. MTT assay and Flow Cytometry (FCM) method were used to test the cytotoxicity of Sr-HA bioceramic. Result shows that there's no obvious cytotoxicity of all the Sr-HA bioceramics. But the cytotoxicity increases as the Stron-tium concentration raising. As the FCM method shows, there's no apparent differ-ence between the pure hydroxyapatite and all of the Sr-HA. Through this in vitro study on cytotoxicity we can come to the conclusion that the Sr-HA bioceramics have no obvious cytotoxicity and may have good biocompatibility, especially 1%, 5% Sr-HA.
Key words: Strontium substituted hydroxyapatite, Cytotoxicity, MTT assay, Flow cytometry