Biodegradable metals for cardiovascular and orthopaedic implants: A comparative review of magnesium, iron and zinc

The advancement of temporary biodegradable implants has intensified interest in metallic systems because of their ability to provide initial mechanical support while promoting biological healing. Among them, magnesium (Mg), iron (Fe), and zinc (Zn) have emerged as the most promising candidates for orthopaedic and cardiovascular applications. Iron-based implants offer excellent mechanical and structural integrity but suffer from excessively slow degradation. Magnesium-based systems display favorable strength and biocompatibility, though their rapid corrosion and hydrogen evolution remain challenges requiring innovative control strategies. Zinc-based implants demonstrate intermediate degradation kinetics and good biocompatibility, positioning them as attractive alternatives for cardiovascular applications despite mechanical limitations. This review highlights recent progress in biodegradable metallic implants, emphasizing their key properties, current challenges, clinical evaluations, and future directions toward safe and effective translation in medical practice.