Comparative study of different polymeric coatings for the next-generation magnesium-based biodegradable stents

Development of next-generation bioabsorbable stents based on magnesium alloys is gaining lots of attention. However, finding an appropriate coating in order to enhance its corrosion resistance along with preserving other requirements is still a challenge. In this study, three FDA-approved polymers, namely poly(lactic acid), polycaprolactone and poly(lactic-co-glycolic acid), have been investigated as potential coatings for magnesium-based stents to enhance their corrosion resistance, biocompatibility and haemocompatibility. Potentiodynamic and electrochemical impedance spectroscopy results demonstrated that PLA and PLGA coating performed better in improving corrosion resistance in comparison with uncoated and other coated samples. Although all coated and bare samples displayed desirable results of haemocompatibility assays, PLA-coated samples showed better outcome in terms of biocompatibility. The results revealed that PLA can be considered as a potential coating material to enhance the main characteristics of magnesium-based bioabsorbable stents.