Advancing biodegradable Mg-Gd-Y alloy for cardiovascular stent applications

The implants of percutaneous coronary intervention are making progress to periodic degradation and the reduction of complications. Thus, magnesium alloys have emerged as excellent candidate materials for preparing cardiovascular stents due to their excellent biodegradability and biocompatibility. This study investigates the effect of Gd content on the mechanical properties and corrosion behavior of Mg-xGd-5Y alloys. The results indicate that Gd dissolved in the Mg matrix, enhancing ultimate tensile strength (UTS of 344 MPa) through a solid solution-strengthening effect and activating Prismatic <a> slip systems to enhance elongation (EL of 15.7%). The Pilling-Bedworth ratio (PBR) of Mg-xGd-5Y alloys was analyzed after being immersed in Hank's Balanced Salt Solution for 24 h, with Mg-10Gd-5Y exhibiting a PBR value of 1.1. Furthermore, the product film of Mg-xGd-5Y alloys, mainly oxides and carbonates, effectively improved corrosion resistance. Mg-xGd-Y alloys with low Gd content (Gd≤10 wt.%) demonstrated good cell compatibility with L929 cells (relative growth rate≥75%). These results suggest that Mg-xGd-5Y alloys (Gd≤10 wt.%) have significant potential for cardiovascular stent application.