COMPARISON OF POLYSACCHARIDE AND POLY(ETHYLENE GLYCOL) COATINGS FOR REDUCTION OF PROTEIN ADSORPTION ON POLYSTYRENE SURFACES

There has been much recent interest in the use of poly(ethylene glycol )s (PEGs) for a variety of biotechnical applications. In the present w ork we have immobilized several cellulose derivatives and dextran on p olystyrene surfaces and have measured the extent of fibrinogen adsorpt ion onto the coated surfaces. Immobilization was achieved by adsorptio n onto clean polystyrene and by covalent linkage of oxidized polysacch arides to polyethylenimine which was ionically bound to polystyrene. C ovalently bound polysaccharides, and adsorbed polysaccharides that are strongly held, compare well with poly(ethylene glycol) in preventing fibrinogen adsorption. The same polymers were coupled to polystyrene l atex particles to permit examination by analytical microparticle elect rophoresis. This investigation suggests that adsorbed polysaccharides form thicker layers than do covalently bound polysaccharides. Despite the polysaccharides being bound at many points along the polymer chain while PEG is bound only at the polymer terminus, the functional equiv alence of polysaccharide and PEG coatings is of significance in interp reting the protein-rejecting ability of polymer-modified surfaces.