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.