Synthesis and in vitro evaluation of Ca-P coating on biodegradable Zn alloys

The burst release of Zn2+ from the naked pure Zn and Zn-based alloys could induce local and systemic toxicity, which limits their clinical applications as biodegradable implants. In order to inhibit the explosive release of zinc ions, a protective Ca-P coating was synthesized on biodegradable Zn alloy. The microstructure, corrosion resistance, antibacterial activity, and biosafety of the Ca-P coating are systematically investigated. Electrochemical tests revealed that Ca-P protective layer has enhanced the anti-corrosion behavior of Zn alloy. Furthermore, Ca-P protective layer showed good biocompatibility, as demonstrated by significantly increased cell viability, good attachment, and spreading at a higher cell density. Besides, the Ca-P coating could also retain the antibacterial ability and inhibit the bacterial adhesion. The Ca-P protective layer synthesized on biodegradable Zn alloy can be considered and applied in future biomedical applications.