Electrophoretic deposition of tetracycline loaded bioactive glasses/chitosan as antibacterial and bioactive composite coatings on magnesium alloys

Electrophoretic deposition (EPD) is a coating technique which is widely applied to improve the biocompatibility and anticorrosive performance of medical metal alloys. In this paper EPD was employed to deposit bioactive glasses(BGs)-chitosan(CS) coating loaded with model drug tetracycline(TCH) on AZ31B magnesium alloy to enhance its anti-inflammation, anti-bacteria, anticorrosion and osteogenic induction properties. The electro-chemical test showed that the corrosion current density of CS-BGs-1.0 TCH coating was 2 orders of magnitude lower than that of bare AZ31B. In vitro biological activity revealed that after 3 d of immersion in simulated body fluid, the surface of the coating was covered with a layer of hydroxyapatite. In vitro drug release test showed that the drug in CS-BGs-1.0 TCH could be effectively released for 504 h, providing resistance to the formation of bacterial film in a long time. In vitro antibacterial tests indicated that the coating significantly improved the antibacterial activity of magnesium alloy against E.coli. As a result, the prepared coating had better corrosion resistance, antibacterial and biological activity. This coating has good potential in the application of medical devices and bone implant materials.