Course-grained molecular dynamics investigation on the effects of uniform electric field on DPPC lipid bilayer: With and without vacuum space

One of the potential ways to decrease the cost of extraction of microalgae products is through the use of high-voltage electrical pulses to electroporate cell membranes. At present, its applicability on industrial scale has yet to be demonstrated. Molecular-level understanding of the electroporation on lipid membranes is needed to optimize the treatment parameters. In this study, the effects of uniform electric field on the area per lipid, bilayer thickness, lateral diffusion and pore formation time of dipalmitoylphosphatidylcholine (DPPC) lipid bilayer with and without vacuum space were studied using molecular dynamics. Exposing the lipid membrane to uniform electric field with a magnitude of 0.272 V/nm would cause pore formation in less than 4 nanoseconds. Increasing the magnitude of electric field will decrease the pore formation time. Electric field magnitudes below this threshold have considerable effect to the structure of the lipid, and minimal effect on its lateral diffusion. Our simulations of isolated fully-hydrated lipid bilayer slabs suggest that the mechanism of electroporation is primarily caused by the water permeation on lipid membrane. Moreover, the rotation of lipids reported by previous studies is not only caused by its reaction to electric field, but also by its hydrophilic and hydrophobic properties.