Self-Healing Magnesium Alloy Coatings For Gbr

Magnesium and its alloys are considered ideal materials for bone implants due to their degradability, excellent biocompatibility, appropriate density, and elastic modulus. However, their application as guided bone regeneration (GBR) barrier membranes remains limited due to the mismatch between their uncontrolled corrosion rate and bone healing rate. This study designs a self-healing coating on magnesium alloys to improve their corrosion resistance and osteogenic potential. This study successfully fabricated a MAO-DCPD (micro-arc oxidation-dicalcium phosphate dihydrate) coating on the magnesium alloy Mg-Zn-Mn-Ca using a combination of MAO and chemical conversion. Evaluations included surface morphology analysis, electrochemical testing, hydrogen evolution experiments, scratch tests, and in vivo studies using a rat bone defect model to assess biocompatibility and osteogenic potential. The DCPD composite coating demonstrated remarkable corrosion resistance, with a degradation rate of 0.53 mm/year, and self-healing properties. It promoted the deposition of calcium-phosphate compounds to repair surface damage in a simulated physiological environment. In vivo studies showed that after 8 weeks of implantation, the DCPD-coated material retained 44.6% of its original volume, significantly higher than the Mg3Zn group. This indicates effective control of the in vivo degradation rate. In summary, this study developed a biodegradable magnesium alloy with self-healing functionality. Surface coating modification optimized its degradation rate and osteogenic capacity, supporting the clinical application of magnesium-based bone implants in GBR.