Polyurethane surfaces modified by amphiphilic polymers: effects on proteinadsorption

Surface modification of polyurethane (PUR) surfaces was carried out by usin g three different amphiphilic polymers. Two of the polymers were graft copo lymers, having backbones consisting of poly(methyl methacrylate-co-ethylhex yl acrylate) and poly(styrene-co-acrylamide), respectively, and poly(ethyle ne oxide) PEO 2000 grafts. The third polymer was a commercially available p oly(ethylene oxide-b-propylene oxide-b-ethylene oxide) block copolymer, Plu ronic 9400. The polymers were designated ACRY, STY2, and PE94, respectively . Surface modification was achieved by adsorption of the amphiphilic polyme rs at PUR surfaces from an aqueous solution, or by blending the amphiphiles into a PUR solution, followed by solution casting of films. The accumulati on of the amphiphilic polymers at the PUR surfaces was observed by XPS and contact angle measurements. The ACRY and PE94 polymers were shown to adsorb poorly at the PUR surface, but gave strong surface effects when present in the PUR matrix. Protein adsorption was measured under static as well as un der flow conditions. The modified surfaces had generally lower adsorption o f blood proteins (HSA, Fg and IgG) than the unmodified PUR surfaces. ACRY b lend modified surfaces had the lowest adsorption. (C) 1999 Elsevier Science Ltd. All rights reserved.