Degradation Resistance and In Vitro Cytocompatibility of Iron-Containing Coatings Developed on WE43 Magnesium Alloy by Micro-Arc Oxidation

Iron (Fe) is an important trace element for life and plays vital functions in maintaining human health. In order to simultaneously endow magnesium alloy with good degradation resistance, improved cytocompatibility, and the proper Fe amount for the body accompanied with degradation of Mg alloy, Fe-containing ceramic coatings were fabricated on WE43 Mg alloy by micro-arc oxidation (MAO) in a nearly neutral pH solution with added 0, 6, 12, and 18 g/L ferric sodium ethylenediaminetetraacetate (NaFeY). The results show that compared with the bare Mg alloy, the MAO samples with developed Fe-containing ceramic coatings significantly improve the degradation resistance and in vitro cytocompatibility. Fe in anodic coatings is mainly present as Fe2O3. The increased NaFeY concentration favorably contributes to the enhancement of Fe content but is harmful to the degradation resistance of MAO coatings. Our study reveals that the developed Fe-containing MAO coating on Mg alloy exhibits potential in clinical applications.