The role of adsorbed proteins in platelet adhesion onto polymer surfaces

Polymer surfaces adsorb plasma proteins upon contact with blood. The nature of this adsorbed layer may determine the extent of platelet adhesion onto these surfaces. It is proposed in this study that incomplete terminal oligosaccharides, galactose, and N-acetyl-glucos-amine in adsorbed fibrinogen and γ-globulin are mainly responsible for the platelet adhesion, possibly via glycosyl transferase reactions. In order to verify these proposed mechanisms, platelet–protein interactions in the bulk state and platelet aggregation caused by the interactions were studied. The study was further extended into the reactions of platelets with adsorbed proteins. Data on protein adsorption from blood plasma onto model polymers (Teflon FEP, silastic rubber, Avcothane, and Biomer) provide supportive evidence for the proposed mechanism. The results discussed in this paper emphasize the important role of protein adsorption onto polymer surfaces and the possible involvement of specific reactions in platelet adhesion.