Influence of surface charges on the rupture of black lipid membranes

Abstract

We investigate the influence of surface charges on the rupture of black lipid membranes ͑BLM͒. Rupture is induced by short electric voltage pulses across the membrane. The average voltage necessary to induce breakdown gives information on the energy barrier of defect formation. The rapid transmembrane voltage decay during rupture allows one to evaluate the kinetics of defect widening. The breakdown voltage is about the same for BLM made of lipids with phosphatidylserine headgroups and for BLM made of lipids with phosphatidylcholine headgroups. Moreover, the breakdown voltage is independent of the ionic strength of the aqueous medium surrounding the BLM. This indicates that the stability of the BLM is not dominated by mutual electrostatic repulsion of the headgroups. However, the breakdown voltage depends on the type of the hydrophobic chains of the lipids. Palmitoyl-oleoyl ͑PO͒ membranes require ϳ100-mV smaller breakdown voltages compared to diphytanoyl ͑DPh͒ membranes. Surprisingly, the rupture kinetics depends on the hydrocarbon chains. It was found to be four times faster for DPh than for PO membranes, and independent of the type of headgroup.

Lipid membranes in external electric fields: Kinetics of large pore formation causing rupture

“…Following Eq. (8), a linear increase suggests a fast rupturing driven by inertia [44,46]. More drastic effects are visible for decorated lipids [47][48][49][50][51].…”

“…Large soap films were spanned across a rim, defects were induced by electrical discharges and the kinetics of film rupture were recorded using a high speed camera [43]. The velocity of the pore rim can range from several meters per second down to micrometers per second [43][44][45][46][47][48][49][50][51]. The observed velocities represent the balance between the mechanical forces exceeding those driving the opening (or closing) of the pore as well as the damping forces.…”

Electroporation Threshold of POPC Lipid Bilayers with Incorporated Polyoxyethylene Glycol (C12E8)

“…The average capacitance of the POPC planar lipid bilayer determined in this study is 0.59 µF/cm 2 , which compares well to the 0.6 µF/cm 2 determined by others. 38,48,49 This capacitance increases mildly to 0.63 µF/cm 2 for the POPC planar lipid bilayers with C 12 E 8 incorporated. Note that in previous studies the authors did not report that C 12 E 8 has an effect to the capacitance of POPC bilayer.…”

Lytic and Non-Lytic Permeabilization of Cardiolipin-Containing Lipid Bilayers Induced by Cytochrome c

“…In the droplet bilayer formation method, the membrane permeability and the membrane integrity can be observed independently: the membrane permeability is monitored by the electrophysiological measurement of membrane ionic current; the membrane integrity is directly visualized by the configuration of droplets (whether the two droplets merge) and is further verified by the disassembly and reassembly of droplet bilayer via moving droplets closer or further away. This anomalous non-lytic but highly permeable state would have been missed if traditional bilayer fabrication schemes were employed, such as the painting method [17], [18] and Montal-Mueller technique [18], [19], [20], in which membrane integrity is often indirectly monitored through the membrane permeability by the electrophysiological measurement of ionic current through the membrane: the membrane is inferred to be ruptured when the current through the membrane is overloaded [18], [20], [21].…”