Osteoblast behavior on TiO2 microgrooves prepared by soft-lithography and sol-gel methods

This study focused on the effects of microgrooved TiO2 surfaces on osteoblast behavior. Microgrooved TiO2 surfaces with different widths (12 mu m and 40 mu m) and flat surfaces were fabricated on glass substrates based on the combination of a sol-gel technique and soft-lithography. Osteoblasts (MC3T3-E1) were cultured on the as-prepared microgrooved and flat TiO2 surfaces. Optical microscopy and scanning electron microscopy were used to analyze the adherent cell behavior by examining the cell morphology. Orientation angle analysis indicated that the cells tended to align along the microgrooves. This tendency was stronger on the microgrooves with smaller widths and became weak with increasing width. Alamar Blue assay indicated that the microgrooves restricted cell proliferation and the alkaline phosphatase assay revealed that the microgrooves limited the differentiation rate. This restriction increased with decreasing microgroove width. The surface energy of the TiO2 surfaces was size-dependent and followed the order gamma (12 mu m) < gamma (40 mu m) < gamma (flat surfaces). Osteoblast proliferation and differentiation on the surface with high surface energy exhibited high proliferation and differentiation rates. These results indicated that surface energy appeared to be a dominant factor for cell activity. Thus, surface energy would be a valuable index for the cell compatibility of a micropatterned surface. (c) 2012 Elsevier B.V. All rights reserved.