A simple model for poration induced electrodeformation of Giant Vesicles

Abstract

This work attempts to understand the mechanism of simultaneous electrodeformation and electroporation in Giant Unilamellar Vesicles (GUVs) using a simple semi-analytical model. The coupled equations of electroporation, electrohydrodynamics, and membrane mechanics are solved within the limit of small deformations. The excess membrane area, generated by electroporation, is assumed to manifest as amplitudes of higher order shape deformation modes, apart from prolate and oblate ellipsoids, seen otherwise under weak AC/DC fields, thereby resulting in prolate or oblate cylindrical or square-shapes. The origin of higher modes is essentially due to electropore-induced, polar angle depen dent membrane conductance. The vesicle correspondingly admits higher order shape deformation modes, apart from the quadrupolar harmonics observed in non-conducting membranes. This is due to the nonlinearity arising from the quadratic dependence of the Maxwell stresses on the electric field. The model qualitatively and semi-quantitatively, with a correction factor (fitting parameter) though, captures the square shape modes for β =1, prolate ellipsoids (cylinders) for β > 1, and oblate cylinders for β < 1, where β =σi/σe is the ratio of the electrical conductivity of the inner fluid (σi) to the outer fluid (σe).