The effect of nanoporous surface on titanium alloy on rat osteoblast

Objective To evaluate the effect of nanoporous surface of titanium alloy on adhesion,proliferation,differentiation and mineralization of osteoblasts.Methods The present study was to prepare a novel nanostructured surface of Ti6Al4V alloy by the severe plastic deformation (SPD).Osteoblasts were cultured on nanoporous, smooth and rough titanium alloy in vitro.The adhesion, proliferation,differentiation and mineralization of osteoblasts were observed by cells counting,scanning electron micrography(SEM),standard MTT assay,reverse transcriptase-polymerase chain reaction(RT-PCR)analysis and fluorescent labeling of calcium deposition.Results The number of cells on the nanoporous titanium alloy was higher than any that of other substrates.The early cellular extension on the nanophase surfaces was observed under SEM.The growth curve of osteoblasts cultured on different surfaces had similar appearance,however,longer exponential phase of growth and higher cell count was observed in osteoblasts cultured on nanoporous surface.Of the examined genes,collagen Ⅰ(COL-Ⅰ),alkaline phosphatase(ALP)and osteocalcin(OC)showed a change in expression with different surfaces.All of them were upregulated on the nanophase surface.In addition, a larger area of calcified nodules on nanophase surface was also observed,compared with the other groups.Conclusion Nanoporous surface technology can improve the early adhesion,proliferation,differential and mineralization of osteoblasts in vitro,which suggests nanometer technology should be further considered for orthopaedic implant applications. Key words: Nanomedicine; Titanium; Osteoblasts; In vitro