Platelet adhesion to artificial red blood cells having different membrane compositions.

Abstract

Sheep hemolysate-loaded artificial red blood cells with different membrane compositions were prepared by making use of the interfacial polycondensation reaction between diamines and terephthaloyl dichloride. When these artificial red blood cells were added to rabbit platelet-rich plasma, the platelets rapidly adhered to the artificial red blood cells and obvious differences were seen in platelet adhesion between cells of different membrane compositions. On the other hand, platelet adhesion was not affected by the membrane composition in the absence of the plasma, suggesting that platelet adhesion is strongly affected by plasma components. Among various substances in plasma, the major components, proteins, could be expected to play an important role in platelet adhesion. Therefore, three kinds of proteins, fibrinogen, γ-globulin and albumin, were chosen as typical plasma components and differences in their adsorption behavior on artificial red blood cells were examined. As a result, it was found that fibrinogen and γ-globulin were adsorbed very rapidly and in large amount on the artificial red blood cells while albumin was very little adsorbed under physiological conditions. It was further found that the rate and amount of protein adsorption were dependent on the membrane composition of the artificial red blood cells. The platelet adhesion was found to be affected by coating of the artificial red blood cells with these proteins, but the results were not consistent with the glycosyl transferase hypothesis. Accordingly, it was considered that the dependence of platelet adhesion on the membrane composition of artificial red blood cells is caused by differences in the complex layers of plasma proteins formed rapidly on the artificial red blood cells.