Journal of Physical Chemistry B, Vol.110, No.51, 26170-26179, 2006
Synthetic polymers and biomembranes. How do they interact?: Atomistic molecular dynamics simulation study of PEO in contact with a DMPC lipid bilayer
The understanding of interactions of poly(ethylene glycol) (PEG) or poly(ethylene oxide) (PEO) with biological interfaces has important technological application in industry and in medicine. In this paper, structural and dynamical properties of PEO at the dimyristoylphospatidylcholine (DMPC) bilayer/water interface have been investigated by molecular dynamics (MD) and steered molecular dynamics (SMD) simulations. The structural properties of a PEO chain in bulk water, at the water/vacuum interface, and in the presence of the membrane were compared with available experimental data. The presence of a barrier for the PEO penetration into the DMPC bilayer has been found. A qualitative estimation of the barrier provided a value equal to similar to 19 kJ/mol, that is, 7 times the value of kT at 310 K.