Enhancing control over the degradation behavior of zinc alloy via MOF coating

Zinc and its alloys provide a scalable alternative to the list of biodegradable metals due to its moderate degradation rates and biocompatible degradation products. However, one of the challenges impeding their clinical applications is the uncontrollable and unstable interfacial reactions between zinc implants and the corrosive media. In this study, we report a facile synthesis of metal–organic framework (MOF) nanocrystal coating with tunable thickness on the high-strength Zn-0.8Li alloy matrix for controlled corrosion. The as-obtained dense and uniform MOF nanocrystals form a strong connection with the zinc matrix via coordination bond so as to maintain the mechanical properties, and meantime provide highly rough surfaces exhibiting tunable wettability. The varied MOF coating thus regulate the interface structure between the zinc matrix and corrosive media to control the degradation behavior. Excellent antibacterial activity and biocompatibility are also achieved because of the unique topology morphologies, surface superhydrophilicity, as well as the dynamic Zn²⁺ release. This study sheds valuable lights on the design of MOF-functionalized metal implants for practical use and also triggers extensive applications of MOF in biomaterials.