4th Annual Mountain West
Biomedical Engineering Conference

Adherent and activated platelets on blood contacting biomaterials are known to lead to thrombus formation at the blood-material interface. Consequently the degree of platelet adhesion and activation on a biomaterial’s surface can serve to predict its hemocompatibility. Here we studied platelet adhesion and activation by comparing spreading kinetics and adhesive contacts on model surfaces with two different surface chemistries and three plasma protein compositions. Briefly, surfaces were prepared by the silanization of fused silica slides to produce a uniform mercaptopropyl silane surface monolayer. Samples with a higher surface energy were prepared by exposing the silanized FS sample to UV light resulting in oxidation of the sulfhydryl groups to negatively charged sulfonate groups. Both surfaces were pre-adsorbed with 10% platelet free plasma, fibrinogen, or albumin protein solutions. Washed platelets were perfused over the surface using a parallel plate flow chamber at a shear rate of 92 s-1 for 5 minutes. Adhesive contacts between spreading platelets and the surface were visualized in real time using reflection interference contrast microscopy. The nature of the pre-adsorbed protein layer was found to control platelet interactions with both sulfhydryl and sulfonate monolayers.