Coarse-grain molecular dynamics simulations of diblock copolymer surfactants interacting with a lipid bilayer

Abstract

The interaction of surfactant diblock poly(ethylene oxide)–poly(ethylethylene) copolymers (PEO–PEE) with a lipid bilayer of dimyristoylphosphatidylcholine has been studied by means of coarse-grain molecular dynamics simulations. The effect of the surfactants on the lipid bilayer was studied over a wide range of diblock copolymer concentrations. The simulations show that the hydrophilic PEO chains adopt different structures at low and high concentrations. In particular, the computed density profiles reveal that the PEO chains extend over a longer range from the bilayer surface, with increasing copolymer concentration. The simulated density profiles are in agreement with the scaling law predictions.

Acknowledgments

This paper is dedicated to Professor Ruth Lynden-Bell. We thank John C. Shelley and Dennis E. Discher for their interest and both the National Institutes of Health and the National Science Foundation for their support.