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Background: Implants osseointegration is affected by cell responses at the bone-implant interface, which depends on the chemical composition,micro topography and wettability of the surface, which, in turn, influence protein adsorption.Aim: To investigate whether hyperhydrophilicity alters surface selectivity for fibronectin, a protein which plays a pivotal role in cell adhesionand proliferation.Materials and Methods: Acid-etched sandblasted surfaces were treated through a proprietary process in order to obtain hyper-hydrophilic surfaces. Surfacefeatures were characterized by X-Ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and themeasurement of the contact angle. Protein adsorption was assessed by SDS-PAGE analysis, and the influence of surface infibronectin adsorption was assayed through Western Blot. Cell attachment to the surfaces was then studied. Murine osteoblastsMC3T3-E1 cells were cultured for 24 hours in complete medium. Their morphology and adhesion were studied through theimmuno-staining for cytoskeleton and for focal adhesions and through the use of SEM microscopy coupled to Focused Ion Beam(FIB). FIB analysis allowed to cut cells during SEM observation and to investigate their interactions with the surface. Furthermore, celladhesion was assessed by quantitating the amount of attached cells to the surface at different experimental points through achemiluminescence assay.Results: Our results showed that the experimental treatment induced a gain of titanium hydrophilicity, without inducing any modification inchemical composition or topography. SDS-PAGE revealed a great amount of proteins adsorbed on treated surfaces, while WesternBlot indicated that hydrophilicity increased the amount of fibronectin adsorbed on the surface.Moreover, hyper-hydrophilic surfaces allowed a closer adhesion of cells. Immuno-staining revealed healthy cells on both surfaces,however cells growing on hydrophilic surfaces expressed a higher amount of focal adhesions. Similarly, the adhesion curve showed afaster cell adhesion to hydrophilic titanium already after 30 minutes of culture. SEM-FIB analysis demonstrated that cells on untreatedsurfaces adhered preferentially to the micro texture peaks, while hyper-hydrophilicity promotes the adhesion of cell body to the peaksthroughout the sample. Cells appeared thinner and spread on the entire surface.Conclusions: Taken together, our data show that hyper-hydrophilicity affects protein adsorption. In particular, we observed a more selectiveadsorption of fibronectin, which may be responsible for improved cell adhesion to micro-patterned titanium.