HA-hybrid matrix composite coating on Ti-Cp for biomedical application

Bioinspired TiO2/Chitosan/HA Coatings on Ti Surfaces: Biomedical Improvement by Intermediate Hierarchical Films

The most common reasons for hard-tissue implant failure are structural loosening and prosthetic infections. Hence, to fix the first problem, different bioinspired coatings were applied to the titanium alloy surfaces in this study, including dual acid-etched, anodic TiO2 nanotubes array (TNTs), anodic hierarchical titanium oxide, micro- and nanostructured hydroxyapatite (HA) layers, and HA/chitosan (HA/CS) nanocomposite coating. XRD and FTIR analysis demonstrated that the in situ HA/chitosan nanocomposite formed successfully. The MTT assay showed that all samples had excellent cell viability, with cell proliferation rates ranging from 120-150% after 10 days. The hierarchical coating demonstrated superhydrophilicity (θ ≈ 0°) and increased the wettability of the metallic Ti surface by more than 120%. The friction coefficient of all fabricated surfaces was within the range of natural bone's mechanical behavior. The intermediate hierarchical oxide layer increased the adhesion strength of the HA/chitosan coating by more than 60%. The Hierarchical middle oxide layer caused the mechanical stability of HA/CS during the 1000 m of friction test. The microhardness of HA/CS (22.5 HV) and micro-HA (25.5 HV) coatings was comparable to that of human bone. An intermediate hierarchical oxide-based mechanism for improving adhesion strength in HA/CS coatings was presented.