A comprehensive study on a novel chitosan/Ag-MOFs nanocomposite coatings for bone implants: Physico-chemical, biological and electrochemical properties

The present study developed new multi-functional coatings made of novel silver-based metal-organic frameworks (SOF) distributed within chitosan (CS) nanofibers network for bone implants. The SOFs were synthesized using environmental-friendly materials via a green process. The CS-SOF nanocomposites were deposited on novel hierarchical etched (HE) layers synthesized through a dual surface treatment. In vitro biological evaluation revealed appropriate biocompatibility for the prepared surfaces. Antimicrobial tests exhibited 100-200% effective antibacterial activities along with significant reduction of bacterial colonies. Electron microscopy illustrated proper cell attachment and growth on the multilayer HE/CS-SOF coatings. The designed surfaces exhibited great apatite formation capability and superior bone bioactivity. Electrochemical studies demonstrated that all surface treatments, shifted the corrosion potential of the titanium substrate to the nobler potentials. The HE/CS-0.50SOF coating showed the noblest corrosion potential of similar to 62.4 mV (vs. SCE). Passivation current density of the titanium surface decreased more than 99% using the HE/CS-0.50SOF coating. The corrosion resistance of the HE/ CS-SOF nanocomposite coatings improved more than 99% by increasing the SOFs concentration. Charge transfer resistance of the HE/CS-SOF nanocomposites improved more than 630% by increasing the SOFs concentration. The results proved that the produced coatings can be promising candidates for biomedical applications.