Enhanced anti-corrosion and biocompatibility of a functionalized layer formed on ZK60 Mg alloy via hydroxyl (OH) ion implantation.

Magnesium and its alloys have piqued the interest of researchers due to their promising mechanical properties and biocompatibility. Moreover, the excessively fast corrosion rate of Mg alloys impedes their development in biomedical fields. Inspired by conventional ion implantation, a less-toxic functional group (hydroxyl) is used as the ion source to bombard the ZK60 Mg alloy surface to form a functionalized oxide layer. The surface characterization, corrosion resistance, and biocompatibility are systematically investigated before and after hydroxyl ion implantation. A smoother surface mainly constituted of hydroxide/oxide is formed for the treated samples. The formed functionalized layer significantly improves the corrosion resistance of the ZK60 Mg alloy substrate and the proliferation of MC3T3-E1 cells, as demonstrated by electrochemical, immersion, and in vitro cytocompatibility tests. In summary, less-toxic functional ion implantation can be an effective strategy for preventing corrosion of Mg alloy implants and promoting their biocompatibility.