Surface nanoporosity of β-type Ti–25Nb–25Zr alloy for the enhancement of protein adsorption and cell response

•Simple electrochemical anodization was applied to β-type Ti25Nb25Zr alloy surface.•Anodized surface had nanoporous topography with pore size < 15 nm.•Surface nanoporosity enhanced protein (albumin and fibronectin) adsorption.•Surface nanoporosity enhanced human bone marrow mesenchymal stem cell responses.•Surface nanoporosity on Ti25Nb25Zr alloy has a potential for implant applications.

This paper outlines a simple method for the electrochemical anodization of β-type Ti–25Nb–25Zr (Ti25Nb25Zr) alloy with a low elastic modulus (approximately 70 GPa) to alter its surface topography for bone implant applications. Surface characteristics including topography, roughness, hydrophilicity, and protein adsorption (fibronectin and albumin) were investigated. Human bone marrow mesenchymal stem cell responses, including adhesion, migration, proliferation, and mineralization, were also evaluated. The experimental results demonstrate that the electrochemical anodization process produced a nanoporous surface (pore size < 15 nm) on Ti25Nb25Zr alloy. This surface nanotopography did not alter the surface roughness or hydrophilicity of the Ti25Nb25Zr alloy but was capable of enhancing biological responses, including protein adsorption, cell adhesion, cell migration, cell proliferation, and cell mineralization. The created surface nanoporosity on β-type Ti25Nb25Zr alloy has a high potential for bone implant applications.