Growth of nanotubular structures on Ti surfaces and plasma surface modification

Keywords: Anodization, TiO2 nanotube, plasma surface modification, drug loading, drug release Increasing traffic accidents, world population, aging and congenital disability reduce the comfort of individuals. Alternative reconstructive orthopedic applications to these disadvantages have attracted biocompatible materials such as titanium into the life with a rising acceleration. Intensive researches are conducted on the development of properties of titanium biomaterials (osseointegration, etc.) for shortening the recovery period after implantation. In this study, TiO2 nanotube layer (TNT) was grown on the Ti-based substrate material surface by anodization in order to increase the surface functionality of Ti-based implants and to improve their use as a local drug dispenser. For this purpose, preliminary anodization studies were performed. According to the results, "Ti6Al4V substrate, ethylene glycol (EG) electrolyte containing 0.5% NH4F and 10% H2O, 40 V potential and 1 hour period" were determined as optimum anodization parameters. The targeted distribution of drugs to the disease site is one of the innovations experienced in the treatment processes in recent years. In this regard, the TNT layer is suitable for use as a drug reservoir. In order to improve the drug loading and releasing properties of TNT structures by improving the wetting behavior of the surface, vacuum plasma surface modification was applied to the TNT surface. By the plasma modification technique, wetting character of the surface was changed from hydrophobic to hydrophilic. TNT samples treated and untreated by plasma surface modification were loaded with a model drug (Gentamicin) by two different methods and the effects of plasma surface modification on drug loading and release behavior were investigated. Accordingly, because the drug release of modified samples is slower as the plasma modification process improved the surface wettability, it was concluded that the drug loaded to the modified samples reached the deeper of the nanotubes. The results of the study are promising for efficient drug loading (deeper into the tubes) and long-term drug release of Ti-based implants.