Bioceramic Coatings on Magnesium Alloys

Magnesium (Mg)-based materials have attracted interest as for its use as a biodegradable metallic implant material. However, one of the main challenges in the use of magnesium and its alloys for biomedical applications is its poor corrosion resistance in physiological environments. Surface coatings to control biodegradation of magnesium offer the flexibility to be easily modified for specific applications and have significantly less investment. Hydroxyapatite-based bioceramic coatings on metallic implants have been favorably viewed because of its excellent bioactivity and biocompatibility and the fact that the composition of hydroxyapatite is similar to that of natural bone. In this manuscript, we discuss the context of magnesium as biodegradable metal, current challenges on use of magnesium-based materials for biomedical applications. Focusing specifically on orthopedic applications, we elaborate on calcium phosphate-based bioceramic coatings. Recent work on hydroxyapatite coatings on magnesium, fabrication process and the biological response of the coatings are highlighted.