Review of the Effect of Surface Coating Modification on Magnesium Alloy Biocompatibility

Magnesium alloy, as an absorbable and implantable biomaterial, has been greatly developed in the application field of biomaterials in recent years due to its excellent biocompatibility and biomechanics. However, due to the poor corrosion resistance of magnesium alloy in the physiological environment, the degradation rate will be unbalanced, which seriously affects the clinical use. There are two main ways to improve the corrosion resistance of magnesium alloy: one is by adding alloying elements, the other is by surface modification technology. Compared with adding alloy elements, the surface coating modification has the following advantages: (1) The surface coating modification is carried out without changing the matrix elements of magnesium alloy, avoiding the introduction of other elements; (2) The corrosion resistance of magnesium alloy can be improved by relatively simple physical, chemical, or electrochemical improvement. From the perspective of corrosion resistance and biocompatibility of biomedical magnesium alloy materials, this paper summarizes the application and characteristics of six different surface coating modifications in the biomedical magnesium alloy field, including chemical conversion method, micro-arc oxidation method, sol-gel method, electrophoretic deposition, hydrothermal method, and thermal spraying method. In the last section, it looks forward to the development prospect of surface coating modification and points out that preparing modified coatings on the implant surface combined with various modification post-treatment technologies is the main direction to improve biocompatibility and realize clinical functionalization.

Automated summary

Magnesium alloy has witnessed significant development in the field of biomaterials due to its excellent biocompatibility and biomechanics. However, its poor corrosion resistance in physiological environments poses challenges for clinical use. This study explores two main approaches to improve the corrosion resistance: alloying elements addition and surface coating modification. Surface coating modification is preferred as it avoids introducing new elements and offers simpler physical, chemical, or electrochemical improvements. The research summarizes and discusses the application and characteristics of six different surface coating modifications in the biomedical magnesium alloy field while highlighting the potential of combining modified coatings with various post-treatment technologies to enhance biocompatibility and achieve clinical functionalization.