Coarse-Grained Molecular Dynamics Simulations of Pegylated Lipids

Polyethylene oxide (PEO) and polyethylene glycol (PEG) are polymers with the subunit C-O-C. Due to their low toxicity and high solubility in water, they have been conjugated (or PEGylated) to the drug transporters such as vesicles and micelles. Experimental results have shown the phase behavior of lipid/PEG-lipid mixtures and characterized their sizes using a disk model with apparent hydrodynamic radius. In this work, we perform coarse-grained molecular dynamics simulations of self-assemblies of a mixture of lipids and PEGylated lipids. Simulations with various concentrations of PEGylated lipids lead to formation of liposomes, bicelles, and micelles, and their sizes were characterized. Phase diagrams show dependence of PEG concentration, length, and temperature.