Effects of Sr-hydroxyapatite microcrystal on cultured cell

Strontium-hydroxyapatite microcrystals (Sr-HAp sol) were produced by a wet method at room temperature with ultrasonic irradiation and were applied to MC3T3-E1, ROS, and L cells for periods of 2, 4, and 6 days in vitro. The effect on cell growth, the variation of LDH and Ca contents in the media, and attachment between cell and microcrystal were investigated. Sintered Sr-HAp and HAp sol were used as controls. A slight inhibitory effect of Sr-HAp sol on cell growth was found. The degree of inhibition was nearly the same as HAp sol. However, it was stronger than sintered Sr-HAp. The contents of LDH in the media increased with the degree of cell inhibition, and the contents of Ca in the media decreased from the initial stage of cell-sol contact. A good attachment of Sr-HAp sol to cultured cells was seen by phase-contrast microscopy and SEM.