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 a new work 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 electrochemical 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.

Antibacterial activity

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.

The study has been published in Progress in Organic Coatings, Volume 184, November 2023.