Ta2O5-doped TiO2 nanotubes on Ti6Al4V alloy with improved cytocompatibility to endothelial cells

Microscopic topography and chemical composition of implant surface play critical roles in cellular response. In this work, Ta2O5-doped TiO2 nanotubes (Ta2O5/TiO2 NTs) were prepared on Ti6Al4V (TC4) to improve its cytocompatibility to endothelial cells. Firstly, a Ta diffusion layer on TC4 (Ta/TC4) was designed by plasma surface Ta-alloying. Then, a Ta2O5/TiO2 NTs film was grown on Ta/TC4 by anodization. The surface morphology, phase composition, and microstructure of the obtained samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Ta incorporation leads to the lamellar microstructure (alpha'+beta) of Ta/TC4 and the lamellar distribution of Ta2O5/TiO2 NTs. In vitro assays demonstrate that the synergistic effect of Ta2O5 addition and biomimetic nanostructure is responsible for the enhanced proliferation, adhesion, cytoskeletal assembly, and spreading of endothelial cells on Ta2O5/ TiO2 NTs. The excellent cytocompatibility of Ta2O5/TiO2 NTs highlights its potential in biomedical applications.