The effect of surface modification of zinc-based biodegradable alloys on their biological and corrosion properties in medical implants: A review

The clinical demand for temporary metallic implants that degrade safely in the body has led to growing interest in zinc-based biodegradable alloys. Zinc possesses a moderate degradation rate and favorable biocompatibility; however, its intrinsic mechanical weakness and uncontrolled Zn2+ ion release compromise its effectiveness as a standalone biomaterial. This review critically explores the limitations of pure zinc and evaluates advanced strategies developed to enhance its performance. Alloying with elements such as Mg, Sr, Cu, and Ti has significantly improved its mechanical integrity, while surface modification techniques—such as anodization to produce nanotubes and plasma treatments—have been shown to regulate its degradation and support cellular interactions. This review emphasizes the synergistic role of alloy design and surface engineering in reducing cytotoxicity and promoting osteointegration. Furthermore, the integration of drug delivery systems into surface structures adds multifunctionality, opening pathways for anti-inflammatory, antibacterial, and pro-regenerative implant functions. These findings provide a roadmap for the rational development of next-generation zinc-based biomaterials suitable for clinical translation.