Abstract
Among the six dialysis membranes ethylene vinylalcohol copolymer (EVAL). DAEA cellulose (He), polyethylene-glycol-graft-edcellulose (PC), cellulose diacetate (CA). polymethyi metacrylate (PMMA), and cellulose (OC), having measured ζ potentials ranging from -2.88±0.38 (EVAL) to +0.86±0.14 (He), total protein adsorption was found to be high on He and minimal on PC and CA. Fibrin adsorption was high on EVAL and PMMA, and minimal on the other four membranes. Two dimensional electrophoresis on polyacrylamide gel showed a different pattern of protein adsorption by each membrane, with albumin adsorption moderate to low on EVAL. He. OC. and PC. and very low on PMMA and CA. Immunobrotting analyses showed EVAL. but none of the other membranes, to have adsorbed proteins which reacted with antibodies to high molecular weight kininogen and factor XIII, thus indicating the activation of the intrinsic coagulation system by EVAL. and also showed EVAL PMMA. and CA to have adsorbed low molecular weight proteins which reacted with fibrinogen antibodies, thus indicating the involvement of proteinase other than plasmin. Observation by scanning electron microscopy revealed adsorption of platelets to be particulaly high on the PMMA. high on the OC, and minimal on the EVAL. He. PC. and CA. These results, taken together, indicate that the PC is superior to the other dialysis membranes in its relative freedom f rom membrane-protein interaction, and thus in biocompatibility.
