Biocorrosion and biocompatibility of absorbable Mg-Li-Y wires for temporary cardiovascular scaffolds

The use of bioabsorbable metals in cardiovascular applications has shown potential to offer clinical advantages over conventional permanent materials such as stainless steel or cobalt-chromium. Among these, magnesium (Mg) is at the forefront of research for bioabsorbable stent design due to its favorable biocompatibility, suitable mechanical properties, controlled absorption kinetics, and a growing body of supportive clinical data. In this study, we determined that the novel magnesium-lithium-yttrium alloy system featured excellent properties as a bioabsorbable material candidate. The corrosion behavior and histological response were assessed at two levels of yttrium content, 0.5% and 2.0% (by weight). This study found that corrosion penetration and cross-sectional area reduction for the two alloys were similar in both in vitro and in vivo tests. Vascular histology revealed that the increase in yttrium content led to a greater initial neointimal growth, which subsided by Day 28. Furthermore, the application of a poly(lactic-co-glycolic acid) (PLGA) coating in one treatment group effectively delayed the progression of corrosion for up to two months, and complete degradation was observed by six months. Overall, the biocompatibility and degradation behavior of magnesium-lithium-yttrium alloys are suitable for vascular scaffolds.