PROTEIN ADSORPTION ONTO CERAMIC SURFACES

Ceramics seldom have been used as blood-contacting materials. However, alumina ceramic (Al2O3) and polyethylene are incorporated into the pi vot bearings of the Gyro centrifugal blood pump. This material combina tion was chosen based on the high durability of the materials. Due to the stagnant flow that often occurs in a continuous flow condition ins ide a centrifugal pump, pivot bearing system is extremely critical. To evaluate the thombogenicity of pivot bearings in the Gyro pump, this study sought to investigate protein adsorption, particularly albumin, IgG, fibrinogen, and fibronectin onto ceramic surfaces. Al2O3 and sili con carbide ceramic (SiC) were compared with polyethylene (PE) and pol yvinylchloride (PVC). Bicinchoninic acid (BCA) protein assay revealed that the amount of adsorbed proteins onto Al2O3 and SiC was significan tly less than that on PVC. The sodium dodecyl sulfate-polyacrylamide g el electrophoresis (SDS-PAGE) indicated that numerous proteins adsorbe d onto PVC compared to PE, Al2O3, and SiC. Identification of adsorbed proteins by Western immunoblotting revealed that the adsorption of alb umin was similar on all four materials tested. Western immunoblotting also indicated lesser amounts of IgG, fibrinogen, and fibronectin on A l2O3 and SiC than on PE and PVC. In conclusion, ceramics (Al2O3 and Si C) are expected to be thromboresistant from the viewpoint of protein a dsorption. (C) 1998 John Wiley & Sons, Inc.