Pre-adsorption of a cellulose ether onto polymer surfaces: adsorption of adhesins and platelet activation

The effect of pre-adsorbed cellulose ethers upon the adsorption of plasma proteins at polymer surfaces was measured by an enzyme-linked immunosorbent assay. The resulting adsorption of plasma proteins was correlated with the sticking and activation of platelets at the blood-material interface, measured by scanning electron microscopy and release of beta-thromboglobulin. Retained Ca2+ activity was made possible by hirudin, a specific thrombin inhibitor, from medicinal leeches as an anticoagulant drug, thereby keeping the initial coagulation cascade and calcium-dependent cell-protein interactions intact during the experiments. The results show that pre-adsorption of a hydrophobic cellulose ether with a flocculation temperature < 37 degrees C, on polyurethane and polytetrafluoroethylene, decreased the adsorption of fibrinogen, fibronectin and vitronectin. A corresponding decrease was found in the number of cells sticking to the surface and in the release of beta-thromboglobulin from platelets.