[A feasibility study on use of surface and interface properties for evaluating hemocompatibility of carbonaceous...

In order to evaluate diamond like carbon film (DLC), DLC containing Si, graphite, diamond film (DF), low temperature isotropic carbon film (LTIC) and SiC, we investigated the correlations between surface energy parameters and hemocompatibility indices such as kinetic clotting time, hemolysis and platelet consumption. An analysis of T-type correlation degree in the Grey system theory was performed. The results showed: (1) all of correlation degrees between kinetic clotting time and polar surface energy parameters were positive, but for critical surface tension, the correlation degree was negative; among five of surface energy parameters, interface tension had the highest relation degree (0.63) with kinetic clotting time, and critical surface tension (-0.43) took the second place; (2) on the contrary, all of correlation degrees between hemolysis and polar surface energy parameters were negative, but for critical surface tension, the correlation degree was positive; and that which had closer correlations with hemolysis were still interface tension (-0.43) and critical surface tension (0.29); (3) critical surface tension had the highest relation degree (0.68) with platelet consumption, and surface tension (0.32) took the second place; (4) kinetic clotting time possessed higher negative correlation degrees with hemolysis (-0.57) and platelet consumption (-0.36). These data indicate that kinetic clotting time depended on a balance between the polarity of surface and the limited humidifying of water on the surface, and that platelet consumption was based on good humidification and power polarity of surface, while hemolysis was promoted by the aid of chromatic dispersion action stemming from the surface and fully humidifying of water on the surface. There was "seesaw effect" between kinetic clotting time and hemolysis or platelet consumption, hence the hemocompatibility of carbonaceous biomaterials could be equivalently evaluated by using kinetic clotting time as an index. It has been confirmed: (1) successive occurrences, including adhesion, deformation and collection of platelets on the material surfaces as results of protein adsorption, are the major mechanism of blood coagulation of carbonaceous materials; (2) the hemocompatibility of carbonaceous biomaterials can be evaluated by using critical surface tension as an index. These findings may underpin the hemocompatibility evaluation of carbonaceous biomaterials based on surface properties.