UV-assisted Ga/In-doped ZnO coating to accelerate polydopamine deposition for surface modification of biodegradable zinc substrate

Biodegradable zinc alloys have emerged as promising materials for cardiovascular implant applications. However, the practical application of biodegradable zinc alloys is restricted by several key challenges, including uncontrolled corrosion, inadequate endothelialization and reperfusion ischemia‑induced neointimal hyperplasia. Herein, UV‑assisted Ga‑doped ZnO (UV/GZO) and In‑doped ZnO (UV/IZO) layers are deposited on pure Zn substrates. These coatings can regulate Zn 2 + release and promote the growth of vascular endothelial cells. Under 325 nm excitation, electron‑hole pairs are generated in GZO and IZO via band‑to‑band transitions. The resulting photo‑induced energy catalyzes H 2 O and O 2 to produce reactive oxygen species (ROS), which act as chemical linking groups that accelerate polydopamine (PDA) deposition. The PDA coating enhances corrosion resistance and serves as an adhesion‑promoting interlayer. An outer PLGA layer forms robust bonds with the UV/GZO(IZO)/PDA‑modified Zn substrate, establishing a “sandwich protection system”. This system significantly improves adhesion force, corrosion resistance and mechanical stability. Moreover, the Zn/UVGZO/PDA/PLGA and Zn/UVIZO/PDA/PLGA coatings exhibit good antibacterial activity and controlled degradation, which prevents direct contact between endothelial cells and the Zn surface and decreases adverse cellular responses.