Response of osteoblast to CVI C/C and HA coating on CVI C/C in vitro

Hydroxyapatite (HA) coating was deposited on chemical vapor infiltration carbon/carbon composite (CVI C/C) by catholic sonoelectrodeposition technique. The morphologies and structure of HA and CVI C/C were characterized by SEM, XPS, ED AX and XRD. In order to investigate the bioactivity and biocompatibility of HA coating, CVI C/C, MC-3T3-E1 osteoblast-like cells were cultured on the surface of two materials in vitro and attachment experiment, proliferation experiment and alkaline phosphatase (ALP) activity experiment were done. The results showed that the HA coating with spherical morphology was composed of flake-like nanocrystal. No statistic difference was found at the primary period of cell attachment experiment. But after 8 hours culture, the number of osteoblasts adhered to HA coating were significantly more than that of adhered to CVI C/C. The SEM observation revealed that osteoblasts spread well on both of materials. It was also found that HA coating enhanced cell proliferation and ALP expression. So it demonstrated that HA coating deposited by catholic sonoelectrodeposition processing improved the biocompatibility of CVI C/C and possessed good bioactivity, and HA coating could speed up the attachment, proliferation, differentiation and maturation of osteoblasts. The attachment mechanism of osteoblasts was a complex course, which was influenced by many factors. The morphology and the bioactivity of material's surface played important roles at the initial period of cell attachment.