Zinc alloys in biomedical implants: A review of mechanical performance and corrosion behavior

Zinc-based alloys are increasingly recognized as biodegradable materials for bone implants. They offer biocompatibility, degrade at a moderate pace, and play vital roles in biological processes. Unlike traditional metallic implants like titanium and stainless steel, which often require removal through a second surgery, zinc alloys gradually dissolve inside the body, obviating the need for secondary surgical interventions. Zinc degrades at a rate between that of rapidly dissolving magnesium and slowly dissolving iron, making it suitable for temporary support during bone healing. However, pure zinc (Zn) faces limitations due to its insufficient mechanical strength and ductility, restricting its use in load-bearing applications. This review examines Zn-based alloys as a solution to these issues; alloying with elements such as magnesium (Mg), lithium (Li), manganese (Mn), copper (Cu), silver (Ag), and precious metals has been extensively studied. Currently, research aims to optimize mechanical properties, biodegradation rates, and surface modifications to enhance clinical performance. Zinc-based alloys offer a promising alternative for orthopedic implants, with growing evidence supporting their potential to reduce the need for secondary surgeries and improve treatment outcomes. Given the significant advancements in the research of Zn-based alloys for clinical use, this review also discusses remaining challenges and future research directions.