Petia Vlahovska, Brown University
January 22, 2015
810 S. Clinton Street, Chicago, IL 60612
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Voltage Driven Morphology Changes in Biomimetic Bilayer Membranes
Living cells maintain electric potential difference across their plasma membrane. Changes in the transmembrane electric field are biologically important signals in physiological processes such as electric-field-directed cell migration in development and regeneration. Pulsed electric fields are used to open pores in the membrane, which enable the delivery of material inside the cell, e.g. for gene transfection. I will present our theoretical and experimental work on the deformation and stability of biomimetic membranes (bilayers assembled from lipids or polymers) in electric fields. Giant vesicles exposed to DC pulses adopt peculiar drum-like shapes and may collapse. Our experiments suggest that the edge separates porated (conducting) and intact (insulating) regions of the membrane. The time dependence of the edge location can serve as a quick method to estimate the critical voltage for membrane poration. Electrohydrodynamic analysis of the collapse dynamics shows that membrane conductance and asymmetry in the embedding electrolyte solutions destabilize the interface; membrane viscosity slows down the growth of the instability. In the case of multicomponent membranes, electric fields induce reversible phase separation.
Jun 17, 2019
Jun 17, 2019