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This paper aimed to assess how four different and representative dental implant surfaces (machined MAC, grit blasted GB, acid etched AE and grit blasted acid etched GBAE) could affect cell adhesion possibly modulating protein adsorption and a paramount cell receptor such as α5s1 integrin. Based on non-contact 3D profilometry, GBAE was rougher than the other surfaces, while GB and AE reached similar intermediate Sa values and MAC resulted the smoothest one. According to X-ray Photoelectron Spectroscopy and Raman spectroscopy, all the surfaces showed amorphous titania with similar amounts of carbon contaminants. The lesser protein adsorption and delayed cell adhesion of GB, which did not hinder cell proliferation, were correlated to the altered dispersive to polar SE ratio, that was at least double-fold for GB (2.6) compared to MAC (0.8), SL (1.3) and AE (1.2). The biological response in vitro relied on β1 integrin activation that cooperated with the putative mechano-protein transient receptor potential vanilloid 4 (TRPV4) in determining the adhesion of the osteoblasts. In fact, it could be rescued by over activating β1 integrin. On the other hand, silencing TRPV4 strongly inhibited cell adhesion on selected substrates, proving the role of this protein in mediating osteoblasts adhesion on titanium substrates.

Atmospheric pressure plasma-dielectric barrier discharge (APP-DBD, open chamber configuration) was used to functionalize polypropylene (PP) fibers surface in order to generate oxidized-reactive groups such as hydroperoxides, alcohols and carbonyl species (i.e. ketones and others). Such a species increased the surface polarity, without causing material degradation. Three different types of plasma mixture (He, He/O 2 , He/O 2 /H 2 O) under three different values of applied power (750, 1050, 1400 W) were investigated. The formed plasma species (O 2 + , O single atom and OH radical) and their distribution were monitored via optical emission spectrometry (OES) measurements, and the plasma effects on PP surface species formation were followed by X-ray photoemission spectroscopy (XPS). Results allowed to better understand the reaction pathways between plasma phase and PP fibers. In fact, two reaction mechanisms were proposed, the first one concerning the plasma phase reactions and the second one involving material surface modifications.