Tantalum coating on TiO2 nanotubes induces superior rate of matrix mineralization and osteofunctionality in human osteoblasts

• A TiO2 nanotube surface structure was coated with tantalum.
• Osteoblast cell response was compared between the tantalum coated and as-formed TiO2 nanotube surface.
• We observed superior rates of bone matrix mineralization and osteoblast maturation on the tantalum coated nanotube surface.

Nanostructured surface geometries have been the focus of a multitude of recent biomaterial research, and exciting findings have been published. However, only a few publications have directly compared nanostructures of various surface chemistries. The work herein directly compares the response of human osteoblast cells to surfaces of identical nanotube geometries with two well-known orthopedic biomaterials: titanium oxide (TiO2) and tantalum (Ta). The results reveal that the Ta surface chemistry on the nanotube architecture enhances alkaline phosphatase activity, and promotes a ~ 30% faster rate of matrix mineralization and bone-nodule formation when compared to results on bare TiO2 nanotubes. This study implies that unique combinations of surface chemistry and nanostructure may influence cell behavior due to distinctive physico-chemical properties. These findings are of paramount importance to the orthopedics field for understanding cell behavior in response to subtle alterations in nanostructure and surface chemistry, and will enable further insight into the complex manipulation of biomaterial surfaces. With increased focus in the field of orthopedic materials research on nanostructured surfaces, this study emphasizes the need for careful and systematic review of variations in surface chemistry in concurrence with nanotopographical changes.