Integrated Zr‐MOF/NH4TiOF3Bilayer Coating on Magnesium for Controllable Corrosion, Cytocompatibility, and Drug Delivery Multifunctionalities

Abstract Magnesium (Mg) and its alloys biodegrade safely in human body for implant applications. The major bottleneck inhibiting their clinical utilizations is the high corrosion rate. Modification with anticorrosive and bioactive coatings is an ideal strategy to break the bottleneck. In this study, a multifunctional coating constructed by Zr‐based metal–organic framework UiO‐66‐NH 2 (UiO) and ammonium trifluorotitanate NH 4 TiOF 3 (NTiF) bilayers (UiO/NTiF) is fabricated onto Mg matrix through facile solvothermal method. The inner NTiF layer can be designed to the adjustable crystal structure with different anticorrosion effects, realizing the controllable corrosion of Mg matrix. The outer UiO layer is capable to further boost the corrosion protection; meanwhile it endows the drug delivery property owing to the intramolecular porosity and functional groups of MOFs. The UiO/NTiF coating appears highly effective in controlling the corrosion and retaining the mechanical integrity of Mg matrix as well as maintaining high bonding integrity. The cytocompatibility assays demonstrate the enhanced cell adhesion, spreading and proliferation on UiO/NTiF coating. The loading/releasing behavior of ibuprofen molecule and density functional theory calculations are performed to investigate the drug delivery of UiO/NTiF coating. This study would shed valuable breakthroughs for design of functional coatings for biodegradable metals and promote extensive applications of MOFs in biomaterials.