Lithium-modified MAO coating enhances corrosion resistance and osteogenic differentiation for pure magnesium

In this study, the MAO coating with and without Li addition was fabricated on pure Mg to enhance corrosion resistance and osteogenic differentiation for pure Mg. The SEM, XRD and XPS were used to analyze the microstructure and chemical composition of the MAO coatings. The immersion test were conducted to evaluate the degradation behavior of the MAO coated Mg in term of pH and hydrogen evolution. MTT and quantitative PCR (qPCR) analysis were performed to assess osteogenic differentiation of the MAO coatings. The results showed that the addition of Li could decrease the number of micropores and cracks on the MAO coating. Accordingly, the Li-MAO coating with less micropores and cracks was found to exist better corrosion resistance compared with Li free MAO coating. More importantly, the in vitro results of MTT and quantitative PCR (qPCR) analysis suggested that Li addition on MAO could promote the osteogenic-related genes expression with respect to Li free MAO coating, indicating a better osteogenic ability of Li-MAO coating.

Automated summary

The study demonstrated that addition of lithium in MAO coating on pure Mg reduced micropores and cracks, leading to improved corrosion resistance and enhanced osteogenic differentiation. The in vitro results showed that lithium addition promoted expression of osteogenic-related genes in comparison to lithium-free MAO coating, indicating better osteogenic potential.