Mesenchymal stem cells in response to exposed rod-heights of TiO2 nanorod films

Cellular responses are strongly sensitive to surface structure, so the optimization of the structures is essential in biomaterial research. In this work, the exposed nanorod-heights in TiO2 nanorod films were adjusted for enhancing cellular responses. The adjustment was realized by incorporating mesoporous bioactive glass (MBG) into the nanorod films via a sol–gel method. The exposed nanorod-heights in the films could be changed from the original ∼300 nm to ∼200 nm and ∼100 nm. The cellular responses on the nanostructured surfaces were evaluated through culturing mesenchymal stem cells (MSCs). The results showed that the films with shortened nanorod-heights had better cellular responses and could accelerate osteogenic differentiation and mineralization, and the films with 100 nm nanorod-height provided the best surface for cell growth. This is attributed to the nanostructure with the shortened nanorod-heights being well recognized by the cells, consequently the cells grew with a faster osteogenic differentiation through a strengthened BMP-smads signal pathway.