Surfaces modified with PEO by the Williamson reaction and their affinity for proteins

Poly(ethylene oxide) (PEO) was immobilized by the Williamson ether synthesis onto halogenated surfaces such as poly(vinylidene chloride), surface-brominated polypropylene, and surface-brominated poly(ethylene terephthalate). PEO (Mw 20,000) was converted to its sodium salt and reacted for various times with the halogen-containing surfaces at 95 degrees C in the melt, or as a solution in 2-methoxyethyl ether. X-ray photon spectroscopy and water contact-angle measurements confirmed the surface-immobilization of PEO. The adsorption from phosphate buffer of human serum albumin, immunoglobulin G (IgG) and fibrinogen, and murine IgG was reduced after modification of the surfaces. In addition, IgG adsorption from pooled human sera was diminished. The difference in protein adsorption between test samples and controls exhibited a strong dependence on input protein concentration.