WITHDRAWN: Characterization of Ag2O nanorods/TiO2 nanotubes hybrid coating for potential orthopedic implant applications

Abstract

In this study, the potential of nanorod/nanotube hybrid arrays for orthopedic coatings was explored. The Ag2O nanorods/TiO2 nanotubes (ANRs/TNTs) hybrid coating was synthesized on Ti6Al7Nb using a multi-step procedure involving primary anodization, annealing, and secondary anodization processes. The process began with primary anodization, fostering the growth of TNTs, succeeded by thermal treatment for crystallization, and deposition of an Ag layer using physical vapor deposition (PVD) magnetron sputtering. Subsequently, secondary anodization was conducted on Ti6Al7Nb, which was initially coated with Ag-deposited TNTs, culminating in the formation of a hybrid coating. In the hybrid coating, the mean inner diameter of the TNTs was measured at 32.2 ± 8.0 nm, while the average inner diameter of the ANRs stood at 59.0 ± 30.6 nm. The hybrid coating exhibited notably higher hardness values (75.8 ± 3.2 HV) compared to both anodic TNTs (HV 45.5 ± 1.0) and crystallized TNTs (HV 54.0 ± 1.6), while its adhesion strength reached 871.5 ± 3.86 MPa, highlighting robust bonding with Ti6Al7Nb. In vitro bioactivity results confirmed bone-like apatite layer formation on ANRs/TNTs hybrid coating after 14 days in simulated body fluid (SBF), indicating enhanced bioactivity. These findings open promising avenues for advanced orthopedic coatings, with potential applications in facilitating osseointegration, drug delivery, and localized treatments in future biomedical applications.