The purpose of this study was to prepare nanometer hydroxyapatite/chitosan composite (nHA/CS) and evaluate its
biocompatibility with rhBPM2 gene transfecting cells. The cell line expressing rhBMP-2 gene was grown, and the nanometer hydroxyapatite powder was fabricated with the sol-gel method and then dispersed completely in 2% chitosan/acetic acid solution. Attachment quantity and morphology of gene-transfecting cells were investigated on nHA/CS and dense HA. It was shown in X-ray diffraction that characteristically diffracted peaks of precipitated HA nanocrystals were identical with those of stoichimetric HA with reference to JCPDS. HA powder in composites was shown to be nanoparticles by transmission electron microscope. After being co-cultured for 3 days, 5 days and 7 days,
the proliferation of attached cells on the scaffold materials was more than that on dense HA. It was believed that compared with dense HA, the novel scaffold material, nHA/CS, had significant ability for cell adherence and considerable improvement in the biocompatibility of hydroxyapatite. Adherence and proliferation of rhBMP2 gene transfecting cells on the surface of nanoHA/CS were better than those on dense HA/CS composite. And the Alkaline phosphatase (ALP) activity from nanoHA/CS was approximately the same as that of dense HA/CS. From these results,
it is suggested that the porous nano-HA/chitosan composite scaffolds are useful materials in tissue engineering research.