Poly(ethylene glycol) grafting to poly(ether imide) membranes: Influence on protein adsorption and thrombocyte adhesion

Abstract

The chain length and end groups of linear PEG grafted on smooth surfaces is known to influence protein adsorption and thrombocyte adhesion. Here, it is explored whether established structure function relationships can be transferred to application relevant, rough surfaces. Functionalization of poly(ether imide) (PEI) membranes by grafting with monoamino PEG of different chain lengths (Mn = 1 kDa or 10 kDa) and end groups (methoxy or hydroxyl) is proven by spectroscopy, changes of surface hydrophilicity, and surface shielding effects. The surface functionalization does lead to reduction of adsorption of BSA, but not of fibrinogen. The thrombocyte adhesion is increased compared to untreated PEI surfaces. Conclusively, rough instead of smooth polymer or gold surfaces should be investigated as relevant models. Structure function relationships have been established for poly(ethylene glycol) (PEG) grafted on smooth surfaces; however, application relevant surfaces are rough. Therefore, it is explored how PEGs of different chain lengths and end groups can shield poly(ether imide) membranes from protein adsorption as well as thrombocyte adhesion and activation. Here, the dynamics of the attached PEG chains are important. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.