Biological and antibacterial properties of composite coatings on titanium surfaces modified by microarc oxidation and sol-gel processing.

The aim of this study was to assess the biological and antibacterial properties of composite coatings on titanium surfaces modified by microarc oxidation and sol-gel processing. A layer of hydroxyapatite (HA) with different concentrations of zinc (Zn) ions, prepared by the sol-gel method, was coated on microarc oxidized Ti (MAO-Ti) substrates. Five groups of specimens were tested. The microstructures, elemental compositions, and chemical phases of the composite coatings were investigated, and the biological and antibacterial properties of specimens were evaluated in vitro. The EDS and XRD results confirmed the composite coatings contained HA and Zn ions which was formed on titanium surfaces. The proliferation and ALP activity of BMSCs was significantly higher in group MAO-Ti+HA and MAO-Ti+HA+Zn(High), but MAO-Ti+HA+Zn(High) showed better antibacterial performance. The MAO-Ti substrate coated with the higher Zn concentration in the HA coating exhibited not only favorable biocompatibility, but also antibacterial action against Gram-negative anaerobic bacteria. [ABSTRACT FROM AUTHOR]