Promotion of osteoblastic differentiation and osteogenic transcription factor expression on a microgroove titanium surface with immobilized fibronectin or bone sialoprotein II.

We demonstrate that a composite surface of microgroove titanium (Ti) with immobilized fibronectin (FN) or bone sialoprotein II (BSP2) promotes osteoblastic differentiation and osteogenic transcription factor expression in human bone marrow-derived mesenchymal stem cells (MSCs). Comparisons made between smooth microgrooves, microgrooves with silanization and microgrooves with matrix protein (FN or BSP2)-immobilization Ti surfaces revealed a significant promotion of in vitro osteogenic activity and osteoblastic differentiation at various timelines of culture. An even more significant increase was verified on microgrooves with a matrix protein-immobilization Ti surface in 28 d time-dependent gene expression of the main osteogenic transcription factors, such as ARF4, FRA1, RUNX2, and OSX. As a result, a synergestic effect regarding the promotion of osteogenic transcription factor expression and osteoblastic differentiation in the matrix protein-microgroove Ti composite surface was confirmed. From a multiple regression analysis using various timelines of osteogenic culture as independent variables, day 13 was verified as the most prominent influential timeline for the promotion of osteoblastic differentiation induced by the matrix protein-microgroove Ti composite surface. The FN- or BSP2-microgroove Ti composite surface resulting from silanization can strongly induce the promotion of osteoblastic differentiation in human MSCs. The proposed surface is expected to be useful in the development of a variety of osteogenic biomaterial surfaces.