Cytocompatibility and osteogenic activity of Ta-Ti-O nanotubes anodically grown on Ti6Al4V alloy

Abstract

Bioactive composition and bionic topography are highly desired in the surface design of biomedical implant materials. Herein, Ta-Ti-O nanotubes (NTs) were anodically grown on a tantalum (Ta) alloyed Ti6Al4V (Ta/TC4) surface. Ta/TC4 shows a scalelike surface and (α'+β) microstructure with a thickness of 11.7 μm, while Ta-Ti-O NTs exhibit a lamellar topography with ∼ 1.0 μm in length and 48.6 nm in diameter. Ta-Ti-O NTs group has the lowest water contact angle of ∼ 16.5° compared with TC4, Ta/TC4, and Ti-O NTs grown under the same electrochemical conditions. In vitro assays show that Ta-Ti-O NTs are non-cytotoxicity to MC3T3-E1 osteoblasts and slightly hamper cellular proliferation, but the adhesion and spreading abilities are significantly enhanced than others. The alkaline phosphatase (ALP), collagen type-1 (COL 1), and extracellular matrix (ECM) mineralization levels of osteoblasts on Ta-Ti-O NTs were also improved and further confirmed by osteogenesis-related gene expressions like ALP, COL 1, OPG, and TGF-β1. The superior osteogenic activities of Ta-Ti-O NTs can be mainly ascribed to the combined effect of Ta2O5 doping and the lamellar distribution of NTs. In summary, Ta-Ti-O NTs film with excellent cytocompatibility and osteogenic activities will find its clinical application in the future.