Grafting of bioactive polymers onto titanium surfaces and human osteoblasts response

1 - ArticleTitanium is widely used in orthopedic and dental implants for its excellent resistance to corrosion and its biocompatibility. In order to improve the long-term osteointegration of titanium, bioactive polymers bearing ionics groups such as sulfonates (sodium polysytrene sulfonate, poly-NaSS) are grafted by a covalent way onto titanium surface. The surface is chemically modified and then bioactive polymers are grafted by radical polymerization. The chemical composition of grafted surfaces is given by ATR/FTIR and XPS which certified the presence of sulfonate groups at the surface of grafted titanium. Quantitative grafting of polyNaSS is determined by a colorimetric method and evaluated at 5 mu g/cm(2). In vitro study is performed in order to see the effect of these bioactive polymers on the mineralization of human osteoblast (line MG63). After 28 days of cultured cells on grafted titanium surfaces and non-grafted ones, the amount of calcium onto surfaces is quantified. The results show that the mineralization of these cells is improved with the presence of polyNaSS. The amount of calcium is increased on grafted surfaces compared to non-grafted ones. Cell adhesion was evaluated. Cells were seeded onto grafted and non-grafted titanium and then subjected to detachment forces. The results show that the attachment of human osteoblasts-like cells is increased for grafted titanium with polyNaSS. A study on titanium surface grafted by polymers bearing ionics groups such as carboxylate and phosphate is in progress. (C) 2007 Elsevier Masson SAS. Tons droits reserves