Osteoblast progenitor cell responses to characterized titanium surfaces in the presence of bone morphogenetic protein-atelopeptide type I collagen in vitro.

The goal of this study was to investigate the effect of bone cell response to titanium (Ti) surfaces in the presence of bone morphogenetic protein (BMP)-atelopeptide type I collagen mixture. The atelopeptide type I collagen was used as a potential carrier for the BMP. Sterilized 600-grit Ti samples were used as substrates for the cell culture study. X-ray photoelectron spectroscopy indicated the presence of TiO2 on the Ti surface. The in vitro cell culture study was performed using an osteoblast progenitor cell line derived from mice (2T9). At confluency, the cells cultured on Ti surfaces were divided into three groups: unstimulated culture, culture stimulated by BMP-atelopeptide type I collagen (40 ng/mL), and culture stimulated by atelopeptide type I collagen (40 ng/mL). The unstimulated and atelopeptide type I collagen cultures were controls in this study. After 4 days of incubation, protein production, alkaline phosphatase (ALP) activity, and hexosaminidase activity were observed to be the highest for cells exposed to the BMP-atelopeptide type I collagen mixture. Statistical differences in cellular protein production and ALP activity were observed between the controls and the surfaces exposed to the BMP-atelopeptide type I collagen mixture. Similarly, a statistical difference in hexosaminidase activity was observed between unstimulated Ti surfaces and surfaces exposed to BMP-atelopeptide type I collagen mixture. However, no statistical differences in protein production, ALP activity, and hexosaminidase activity were observed between cells exposed to atelopeptide type I collagen solution and the unstimulated surfaces.