Effect of microphase separation on the protein resistance of a polymeric surface

Segmented polyurethanes (PUs) containing poly(ethylene glycol) (PEG), poly(propylene glycol), or poly(dimethylsiloxane) soft segments have been prepared by two-step condensation polymerization. Atom force microscopy observation in air and solution indicates that the segmented PU forms a microphase separation on the surface. By use of quartz crystal microbalance with dissipation and surface plasmon resonance, we have investigated the adsorption of fibrinogen, bovine serum albumin, and lysozyme on a surface constructed by such a PU in aqueous solution in real time. Our results reveal that the protein resistance of the PUs arises from the hydrated PEG segments instead of microphase separation.