Sol-Gel Derived Antibacterial Ag-Containing ZnO Films on Biomedical Titanium

ZnO and Ag-containing ZnO (ZnO/Ag) films with the Ag/Zn molar ratio of 3.3 and 9.1%, respectively were sol-gel coated on biomedical titanium for antibacterial and bioactive surface modification. X-ray diffraction analysis indicates that ZnO peaks increase with the calcination temperature of the samples. Scanning electron microscopy and energy dispersive of X-ray analyses reveal Ag-rich white particles (300~750 nm) on ZnO/Ag samples that were calcined at 400 °C. X-ray photoelectron spectroscopy analysis of ZnO/Ag samples shows that Zn and O exist as ZnO and Ag presents in metallic state. The coating samples exhibit similar UV light-induced hydrophilic conversion behavior. Potentiodynamic polarization test in a Ca-free Hank's balanced solution demonstrates better corrosion resistance of the coating samples compared with the polished sample. In the in vitro bioactivity test using the simulated body fluid, a layer of apatite is gradually deposited on the surface of sample ZnO/9Ag after 12 days of soaking. The MTT assay test shows that ZnO and ZnO/Ag films have weak compatibility with the L929 cells. The antibacterial test against E. Coli by the disk diffusion assay reveals that antibacterial activity of the coating samples increases with silver content of the films.