Programmable chronopotentiometry as a tool for the study of electroporation and resealing of pores in bilayer lipid membranes

Abstract

This paper presents the application of chronopotentiometry in the study of membrane electroporation. Chronopotentiometry with a programmable current intensity was used. The experiments were performed on planar bilayer phosphatidylcholine and cholesterol membranes formed by the Mueller-Rudin method. It was demonstrated that a constant-intensity current flow through the bilayer membranes generated voltage fluctuations during electroporation. These fluctuations (following an increase and decrease in membrane conductance) were interpreted as a result of the opening and closing of pores in membrane structures. The decrease in membrane potential to zero did not cause the pore to close immediately. The pore was maintained for about 200 s. The closing of the pore and recovery of the continuous structure of the membrane proceeded not only when the membrane potential equalled zero, but also at membrane potentials up to several tens of millivolts. The fluctuations of the pore were possible at values of membrane potential in the order of at least 100 mV. The size of the pore changed slightly and it closed after some time below this potential value.

Investigations into the Correlation Properties of Membrane Electroporation-Induced Inward Currents: Prediction of Pore Formation

“…Consistent with the findings of previous studies [1,3,34], generation of I MEP is believed to be stochastic, in that the distribution of membrane lifetimes in GH 3 cells was observed for the same transmembrane voltage. The stochastic origin of I MEP described here apparently is not a result of inhomogeneous distribution in the charging of membrane during externally applied electrical field [5,6], because a relatively homogeneous charging of membrane during large membrane hyperpolarizations was established in this study.…”

“…Membrane electroporation (MEP) is long recognized to exert a drastic increase in the electrical conductivity and permeability of the plasma membrane by applying externally electrical field [1][2][3]. This method has been widely employed in cancer research, gene transfection, drug delivery, and cell fusion [2,4].…”

A System for the Determination of Planar Lipid Bilayer Breakdown Voltage and Its Applications

“…Usually, this method is appropriate for measuring the resistance of lipid bilayer and the mass flow. It is believed that during these kinds of measurements, the lipid bilayer is more stable due to less voltage stress [27], [30]; therefore, small changes in the membrane structure can also be observed. Scalas et al [31], for example, reported on the time course of voltage fluctuations that followed an increase of the membrane conductance due to the opening and closing of hydrophilic pores [28], [31], [40].…”

“…Under current-clamp conditions, the transmembrane voltage increases slowly; therefore, stable pores could be formed [27], [29], [32], [41]. The creation of the first pore in the planar lipid bilayer causes a fast reduction in transmembrane voltage, which decreases the probability of next pore creation [27].…”

“…The creation of the first pore in the planar lipid bilayer causes a fast reduction in transmembrane voltage, which decreases the probability of next pore creation [27]. Because the pore size is voltage dependent, the pore size decreases.…”