Tóm tắt

In vitro studies have consistently shown that titanium surface wettability affects the response of osteoprogeni-tors, leading to important advances in the clinical osseointegration of dental implants. However, the underlyingrnmolecular mechanisms remain unknown. Since surface conditioning by blood components initiates withinrnmilliseconds after insertion, it is reasonable to hypothesize that the amount and the type of blood proteinsrnadsorbed influences the interaction between the implant surface and osteoprogenitors.rnTo test this hypothesis, titanium implant surfaces with different characteristics, in terms of topography andrnwettability, have been conditioned with selected plasma proteins. Purefibronectin (HFN) and albumin (HSA)rnsolutions, or their mixture at the relative plasma concentrations were allowed to adsorb on titanium surfaces forrn60 min. Protein adsorption was monitored by Bradford assay, while the contribution of HSA and HFN in formingrnthe microfilm layer at the interface was studied by Western Blot. Subsequently, the same protein-conditionedrnsurfaces were used to culture C2C12 cells, thus studying their capacity to adhere and to spread after 3 h. Cellrnviability was evaluated up to 7 days, while the expression of osteogenic genes was assessed after 3 days.rnUnder competitive adsorption conditions, hydrophilicity promotes the selectivity of titanium for HFN re-gardless of the surface microtopography. As a consequence of selective HFN adsorption, cells on hydrophilicrnsurfaces displayed enhanced adhesion and spreading, as well as increased proliferation. On the other hand,rnselective HFN adsorption did not appreciably affect cell differentiation.rnThese data suggest that implant surface hydrophilicity plays a key role in guiding the selective adsorption ofrnspecific proteins from blood plasma. Moreover, the selective adsorption of HFN, as a consequence of surfacernhydrophilicity, was found to account for early cell responses amelioration. Thus, titanium surface hydrophilicityrncontributes to the clinical success of dental implant by selectively controlling protein adsorption at the interface.