γLW increased slightly (significant, p < 0.01, after 1 h and 168 h of exposure)
when immersed in NaCl + BSA, Table 4, compared with freshly polished and aged coupons. There was no significant difference for γ+. Similar trends were observed for stainless steel exposed to citric acid (pH 2.4), Fig. 4, with increased amounts of released iron and calculated γ− values ( Table 4), and reduced water contact angles with time, Figs. 4a and b. There was also a clear correlation between released amounts of iron and both γ− values and water contact angles, Fig. 4c. The difference of the polar component γ− was significant (p < 0.05) after 24 and 168 h of exposure to citric acid, compared to freshly polished and aged coupons. Corresponding differences for the γLW and the γ+ components were significant (p < 0.05) after 1 and 168 h (γLW), and 168 h (γ+) of exposure in citric DAPT order acid, Table 4. The results imply that all surface energy components increase with time, indicating a surface with increasingly see more amphoteric properties. The results indicate a layer of citrate that becomes more compact and ordered after approximately 24 h of exposure, when low contact angles were observed, approaching conditions for a totally wetted carboxylated surface (<10°) [65]. In all, observed findings indicate that the surface energy increases with time and correlates with released amounts of iron. The objective of this study was
to elucidate the importance and connection between surface physicochemical characteristics including surface energy and wettability and surface oxide composition with the release of iron from stainless steel surfaces in complexing biological media. No correlation was observed between the surface
oxide composition of stainless steel (grade AISI 304) and calculated surface energies or the wettability for polished, aged surfaces in non-complexing solutions. Instead, the surface contamination (adventitious atmospheric carbon or from cleaning Teicoplanin solvents) probably strongly influenced the surface energy of stainless steel. The amount of released iron from stainless steel in solutions containing BSA or citrate (10 mM NaCl + 10 g/L BSA, 5 g/L citric acid) strongly correlated with the measured wettability and calculated surface energy. The surface energy components (γLW, γ+, γ−) increased and the static water contact angles decreased with increased amount of released iron. These observations and the delay in released amounts of iron with time strongly suggest an adsorption-controlled ligand-induced metal release process in the presence of BSA and citrate. The Swedish Research Council (VR), grant number 2013-5621, and Göran Gustafsson’s prize for young researchers (J. Hedberg) are gratefully acknowledged for financial support. “
“Les auteurs demandent de remplacer le mot « résection » par le mot « ovariectomie », à trois reprises, dans le texte de leur article : 1.