[Morphological changes of osteogenic cells on hydroxyapatite ceramics sintered at different temperatures]

In order to clarify the relation between the synthetic condition and the biocompatibility in vitro, a dynamics of the osteogenic MC3T3-E1 cells cultured on hydroxyapatite ceramics (HAC) was examined. HAC used in this study was sintered at temperatures of 1000 degrees C or 1350 degrees C to produce the dense ceramics material, and then smoothly surfaced (0.3 micron). Disk (diameter: 10mm, thickness: 1mm) of HAC were placed in plastic disk. The cells were inoculated at 3000 cells/disk on HAC, and cultured for up to 18 Days. In scanning electron microscopic observation, cell proliferation cultured on the polished HAC was more active than that on the unpolished HAC. Furthermore, cell proliferation cultured on the 1000 degrees C-HAC was more active than that on the 1350 degrees C-HAC. Width, length and concentration of microvilli (MV) on the cell surface cultured on the 1000 degrees C-HAC were more dense, and increased with cultivation. Length and concentration of MV of the cells cultured on the 1000 degrees C-HAC were more dense than that on the 1350 degrees C-HAC. Most of the cells cultured on each material were intensely positive with alkaline phosphatase or von Kossa staining. However, the cells cultured on the 1000 degrees C-HAC were more positive than those on 1350 degrees C-HAC. In conclusion, these results suggest that the synthetic condition of HAC have close connection with the biocompatibility.