Enhanced anticorrosive, antimicrobial and biocompatible properties of AZ91D magnesium alloy by MAO-polycaprolactone-modified ZnO composite coating
Wei He, Zijie Shao, Jianghai He, Yulin Zhang, Mengge Sun, Yaqi Jiang, Zhenguo Wen, Fei Chen, Fei Chen
Abstract
Magnesium alloys are biodegradable metal implant materials that are prone to corrosion in human body fluids and are poor biocompatible as a consequence. Herein, we report the preparation of a ceramic layer on an AZ91D magnesium alloy using the micro-arc oxidation (MAO) technique, after which polycaprolactone/citric-acid-monohydrate-modified nano‑zinc oxide was composited on the ceramic layer using a sol–gel method. The MAO-polycaprolactone-modified ZnO composite coating exhibited superior corrosion resistance compared to magnesium alloy, and a higher electrochemical impedance in simulated body fluid (1.0397 × 10 7 vs. 8.444 × 10 2 Ω·cm 2 ). Furthermore, data from immersion, antimicrobial, hemolysis, cell-viability, and-proliferation testing revealed that the composite coating is significantly more antimicrobial and biocompatible than the magnesium alloy. We conclude that such composite coatings have considerable potential for use in biomedical orthopedic-implant applications.