Biocompatibility of pure iron for biodegradable stents: Effects on human coronary aorta endothelial cells

Iron (Fe)-based metals are promising for the development of biodegradable cardiovascular stents due to their mechanical strength, ductility, and degradability. However, Fe corrosion generates compounds that can damage cells, but this remains insufficiently explored. This study investigated the effects of pure iron on human coronary artery endothelial cells through a series of in vitro assays. Surface morphology, roughness, hydrophilicity, and chemical composition of iron—including a pre-incubated condition that mimics a 24 h implantation period—were characterized and related with cellular responses. Overall results indicated that cellular morphology and proliferation were negatively affected by the direct contact with iron but not by it extracts or indirect contact, suggesting a role of short-half-life molecules and insoluble products of iron corrosion. Interestingly, iron pre-incubated with protein-supplemented serum enhanced cellular angiogenic function.