Adsorption of plasma proteins on polyethylene oxide-modified lipid bilayers studied by total internal reflection fluorescence

Distearoylphophatidylcholine (DSPC) mixed with various mole percentages of polyethylene oxide (number average molecular weight 2000)-grafted distearoylphosphatidylethanolamine (PEO2000-DSPE) were deposited on DSPE-coated quartz surfaces by the Langmuir–Blodgett deposition. Structural transitions in PEO2000 from pancake to mushroom, and from mushroom to brush conformations were revealed from film balance experiments. Adsorption kinetics of proteins from 1% platelet-poor plasma (PPP) on the supported lipid bilayers were studied using intrinsic total internal reflection fluorescence. All the supported lipid bilayers exhibited over a magnitude reduction in adsorbed plasma proteins, compared with the quartz substrate. The increase of PEO2000-DSPE density in the mixed bilayers slightly increases the amount of adsorbed proteins on the bilayers.