Influence of nanometer smoothness and fibronectin immobilization of titanium surface on MC3T3-E1 cell behavior

The aim of the present study was to evaluate the influence of mechanical treatment, namely, nanometer smoothing (Ra: approximately 2.0 nm) and sandblasting (Ra: approximately 1.0 μm), as well as biochemical treatment, namely, fibronectin immobilization, of a titanium surface on osteoblast‐like cell behavior. Cell proliferation was monitored by measurements of DNA content and ALP activity; osteocalcin production and mineralization behavior were also evaluated, in addition to morphological observation of attached cells. Fibronectin could be immobilized by the tresyl chloride‐activation method. A sandblasted surface resulted in significantly more DNA than a nanometer‐smooth surface, but fibronectin immobilization did not result in a significant increase of DNA at 52 days of cell culture. The nanometer‐smooth surface showed highest ALP activity and osteocalcin production. FN immobilization decreased ALP activity for the nanometer‐smooth surface, but increased it for the sandblasted surface. The nanometer‐smooth surface also showed the highest osteocalcin production. Scanning electron microscopy showed interesting phenomena of the attached cells. Attached cell area was more rapidly increased on the nanometer‐smooth surface than on the sandblasted surface. It was suggested that cultured cells on the nanometer‐smooth surface began to spread earlier and that the proportion of spreading cells among total attached cells increased sooner on the nanometer‐smooth surface than on the sandblasted rough surface. It appeared that FN immobilization influenced the arrangement of attached cells. In conclusion, the nanometer‐smooth surface employed in the present study was beneficial for the differentiation of MC3T3‐E1 cells. FN immobilization influenced the morphologies of attached cells. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 2012.