Anticorrosion and biocompatibility of a functionalized layer formed on ZK60 Mg alloy via hydroxyl ion implantation

TL;DR

This study demonstrates that hydroxyl ion implantation on ZK60 Mg alloy creates a functionalized oxide layer that improves corrosion resistance and biocompatibility, offering a promising approach for biomedical magnesium alloy applications.

Contribution

It introduces a novel hydroxyl ion implantation method to enhance corrosion resistance and biocompatibility of Mg alloys, comparing favorably to previous carboxyl ion treatments.

Findings

Hydroxyl-treated alloys show slightly higher corrosion rates than carboxyl-treated ones.

Hydroxyl implantation significantly improves cell proliferation and biocompatibility.

The method is a less-toxic alternative for Mg alloy surface modification.

Abstract

Magnesium and its alloys have aroused tremendous interests because of their promising mechanical properties and biocompatibility. However, their excessively fast corrosion rate hinders the development of Mg alloys in the 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. This functionalized oxide layer significantly facilitates the corrosion resistance of the ZK60 Mg alloy substrate and the proliferation of MC3T3-E1 cells, which is confirmed by electrochemical, immersion, and in vitro cytocompatibility tests. In comparison with results of ZK60 alloy implanted with carboxyl ions in our previous work, it is concluded that hydroxyl-treated alloys exhibit slightly higher corrosion rate while better biocompatibility. In summary, less-toxic functional ion implantation can be an effective strategy for inhibiting corrosion of Mg alloy implants and promoting their biocompatibility.