Drug-release characteristic and biological toxicity of TiO2 nanotube/hydroxyapatite loaded vancomycin coating / 中国组织工程研究

ABSTRACT

BACKGROUND: In the scheme of titanium surface modification and coating modification, the drug sustained-release system constructed by surface nanotube modification and hydroxyapatite coating modification has broad clinical application prospects. OBJECTIVE: To construct composite drug loading coating of titanium dioxide nanotube/hydroxyapatite loaded with vancomycin hydrochloride, and analyze the drug release performance and cytotoxicity of the composite coating in vitro. METHODS: A two-step anodic oxidation method was used to construct titanium dioxide nanotubes on the titanium surface, and the prepared hydroxyapatite was loaded on the surface of the nanotubes by electrophoretic deposition, so as to obtain a nanotube/hydroxyapatite composite coating structure. Subsequently, the composite coating was used as a drug-loaded platform, and vancomycin hydrochloride was loaded by physical adsorption to finally obtain a composite drug-loaded coating. The in vitro drug release properties of hydroxyapatite/vancomycin hydrochloride, titanium dioxide nanotubes/vancomycin hydrochloride, titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride coating were measured. Human osteoblasts were cultured with titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride coating extracts of different concentrations. MTT assay was used to detect cytotoxicity. Human osteoblasts were inoculated on the surface of hydroxyapatite, titanium dioxide nanotubes, titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride, and the changes of cell morphology were observed. RESULTS AND CONCLUSION: (1) Compared with hydroxyapatite/vancomycin hydrochloride, titanium dioxide nanotube/vancomycin hydrochloride coating, titanium dioxide nanotube/hydroxyapatite/vancomycin hydrochloride coating had a longer drug sustained-release effect. The release time exceeded 150 hours. (2) The 10%, 50%, and 100% concentration of titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride coating extract had no obvious cytotoxicity. The relative activity of osteoblasts was more than 70%. (3) The osteoblasts on the three kinds of coating surface grow well; the cytoskeleton was intact; and the nucleus-cytoplasm ratio of the cells was normal, which was not significantly different from the morphology of the cells in pure culture. (4) The results show that the coating of titanium dioxide nanotubes/hydroxyapatite/vancomycin hydrochloride has good drug release properties in vitro without obvious cytotoxicity.