Effect of nanotube diameters on bioactivity of a multifunctional titanium alloy

► Amorphous nanotubes of Ti-24Nb-4Zr-8Sn alloy prepared on by anodic oxidation. ► Their outer diameters controlled as 30, 50, 70 and 90 nm. ► Investigation of biological behavior of MG-63 osteoblasts in response to diameters. ► The 30 and 90 nm groups have the highest and the lowest cell viability respectively. ► The polished pure Ti and Ti-24Nb-4Zr-8Sn alloy have identical cell response.