Dynamics of Electroporation of Synthetic Liposomes Studied Using a Pore-Mediated Reaction, Ag⁺ + Br^- → AgBr

Abstract

The dynamics of electric field-induced transient pore formation (electroporation) is studied in 178 nm diameter synthetic unilamellar bilayer liposomes, prepared from the surfactant dioleoylphosphatidylcholine (DOPC). With Ag + ions entrapped in the interior compartment of the vesicle and Br -ions placed in the bulk medium, details of the poration process are revealed through the pore-mediated production of (AgBr) n clusters which are detected spectrophotometrically in the UV. The field-induced elongation of the spherical bilayer shells to prolate ellipsoids is monitored through the transient birefringence of the system. Effects of the field strength E, pulse length, and number of the high-voltage square pulses applied are investigated, and threshold values of these parameters necessary for electroporation are established. It is found that polarization and elongation of the liposomes precede pore opening by 30 µs, and that 75% of the entrapped Ag + ions are ejected during a single pulse into the bulk solution, where the indicator reaction Ag + + Br -f AgBr takes place.

Electroporation of Cell Membranes: The Fundamental Effects of Pulsed Electric Fields in Food Processing

“…In addition, this value is close to 1 nm proposed from purely theoretical assumptions [122,125,132] and the experimental estimations of the pore size, showing that the smallest radius of created metastable pores is in the range of 0.3 nm [53,57,58,60,62,64].…”

“…, and Na ? ions are in the range of 0.16-0.33 nm [61], which means that the smallest radius of created pores can be in the range of 0.3 nm [57,60,62]. Because of this, using the test molecules that are larger than the small ions of K ?…”

“…3, it follows that for a spherical cell with the thin non-conductive plasma membrane (k m = 0), parameter f s = 3/2. Equation 2 is often used to evaluate the transmembrane potential generated by the external electric field [52,62,[91][92][93]. By using membrane potential-sensitive fluorescent dyes, it was confirmed experimentally that Eq.…”

On the investigation of the bilayer functionalities of 1,2-di-oleoyl-sn-glycero-3-phosphatidylcholine (DOPC) large unilamellar vesicles using cationic hemicyanines as optical probes: A wavelength-selective fluorescence approach

“…Results obtained from small unilamellar vesicles (SUV) are often controversially discussed as model systems for cells because of their small size and bilayer defects due to their high curvature. For this reason, it is common the use of large unilamellar vesicles (LUV) to get closer to cell-like structures [3][4][5][6].…”

An Alternative Approach to Quantify Partition Processes in Confined Environments: The Electrochemical Behavior of PRODAN in Unilamellar Vesicles

“…The monodispersity of the LUV size achieved through this technique was previously checked. [6,7,37] The unilamellar nature of the pure DOPC vesicles prepared by using the extrusion method [37] was previously confirmed [4,5,7,38] by measuring the extent of quenching by Mn + 2 of their 31 P NMR signals. [39] All samples were used immediately after preparation.…”