Extent Of Electroporation Research Articles

Quantitative evaluation method of triboelectric nano-electroporation based on electrical impedance spectroscopy

Electroporation refers to a biophysical process wherein cell permeability is altered by inducing pores of the cell membrane through application of an electric field. It has found extensive applications in cancer therapy and gene delivery. The alteration of electrical impedance during electroporation was investigated by synergistically employing a self-powered triboelectric nanogenerator (TENG) and electrical impedance spectroscopy (EIS), thus serving as a theoretical foundation for real-time efficacy assessment of electroporation in clinical settings. A self-powered electroporation experimental system was established, and the findings demonstrated that upon reaching the threshold level of cell transmembrane potential, the application time of electric field led to electroporation of the cells, resulting in a decline in the impedance value of the blood. As the electric field persists, the impedance value gradually diminishes; when the blood impedance value changes insignificantly, the degree of cell electroporation is saturated. During the process of tumor cell electroporation, the relationships between HeLa cell impedance Z* and time T and cell concentration C is Z* = 7×10−11T5- 4×10−8T4+9×10−6T3-8×10−4T2+0.0117T-9.3587 C+124.2. Simultaneously, the occurrence and reversibility of electroporation were verified through Propidium Iodide (PI) fluorescence staining. The numerical calculations presented in this paper are based on the extended HANAI theory. Furthermore, the simulations were conducted through finite element analysis and perform equivalent circuit fitting on the experimental data. The numerical and simulation results are consistent with the experimental findings, validating the study's establishment of a quantifiable relationship between electroporation degree and cell parameter Z*、Rc、Xc and RRBC. As evidenced, the alteration in electrical impedance spectra can effectively indicate the extent of electroporation. Therefore, it is expected that employing the EIS approach will become an effective means to measure the therapeutic efficacy of electroporation in future clinical applications.

Pulse Duration Dependent Asymmetry in Molecular Transmembrane Transport Due to Electroporation in H9c2 Rat Cardiac Myoblast Cells In Vitro.

Electroporation (EP) is one of the successful physical methods for intracellular drug delivery, which temporarily permeabilizes plasma membrane by exposing cells to electric pulses. Orientation of cells in electric field is important for electroporation and, consequently, for transport of molecules through permeabilized plasma membrane. Uptake of molecules after electroporation are the greatest at poles of cells facing electrodes and is often asymmetrical. However, asymmetry reported was inconsistent and inconclusive—in different reports it was either preferentially anodal or cathodal. We investigated the asymmetry of polar uptake of calcium ions after electroporation with electric pulses of different durations, as the orientation of elongated cells affects electroporation to a different extent when using electric pulses of different durations in the range of 100 ns to 100 µs. The results show that with 1, 10, and 100 µs pulses, the uptake of calcium ions is greater at the pole closer to the cathode than at the pole closer to the anode. With shorter 100 ns pulses, the asymmetry is not observed. A different extent of electroporation at different parts of elongated cells, such as muscle or cardiac cells, may have an impact on electroporation-based treatments such as drug delivery, pulse-field ablation, and gene electrotransfection.

Low field MRI study of the potato cell membrane electroporation by pulsed electric field

The effects of high voltage pulsed electric fields (PEF) applied to potato tubers were examined by the contrast enhanced, low field Magnetic Resonance Imaging (MRI). This is a non-destructive, and relatively inexpensive method that allows to monitor the spatial distribution of damages caused by the pulses and their evolution in time. The MRI results confirmed the irreversible damage of the potato tuber cell membranes caused by the PEF treatment, leading to non-selective flow of ions. The extent of electroporation was also evaluated by electrical conductivity measurements, as well as by compression tests and compared with the MRI. On the basis of these results, the PEF method can be optimized in applications aiming at the increase of the permeability of potato cell membranes.

Cell electrofusion using nanosecond electric pulses

Electrofusion is an efficient method for fusing cells using short-duration high-voltage electric pulses. However, electrofusion yields are very low when fusion partner cells differ considerably in their size, since the extent of electroporation (consequently membrane fusogenic state) with conventionally used microsecond pulses depends proportionally on the cell radius. We here propose a new and innovative approach to fuse cells with shorter, nanosecond (ns) pulses. Using numerical calculations we demonstrate that ns pulses can induce selective electroporation of the contact areas between cells (i.e. the target areas), regardless of the cell size. We then confirm experimentally on B16-F1 and CHO cell lines that electrofusion of cells with either equal or different size by using ns pulses is indeed feasible. Based on our results we expect that ns pulses can improve fusion yields in electrofusion of cells with different size, such as myeloma cells and B lymphocytes in hybridoma technology.

Modelling single cell electroporation with bipolar pulse parameters and dynamic pore radii

We develop a model of single spherical cell electroporation and simulate spatial and temporal aspects of the transmembrane potential and pore radii as an effect of any form of applied electric field. The extent of electroporation in response to sinusoidal electric pulses of two different frequencies in a range of extracellular conductivity for two different cell radii are compared. Results show that pore radii tend to be more normalized for AC fields. The relative difference in fractional pore area is reduced by the use of a 1 MHz sinusoidal applied electric field over a 100 kHz field.

Single-Cell Transfection by Electroporation Using an Electrolyte/Plasmid-Filled Capillary

Single-cell transfection of adherent cells has been accomplished using single-cell electroporation (SCEP) with a pulled capillary. HEPES-buffered physiological saline solution containing pEGFP plasmid at a low concentration (0.16 approximately 0.78 microg/microL) filled a 15 cm long capillary with a tip opening of 2 microm. The electric field is applied to individual cells by bringing the tip close to the cell and subsequently applying one or two brief electric pulses. Many individual cells can thus be transfected with a small volume of plasmid-containing solution (approximately 1 microL). The extent of electroporation is determined by measuring the percentage loss of freely diffusing thiols (chiefly reduced glutathione) that have been derivatized with the fluorogenic ThioGlo 1. A mass transport model is used to fit the time-dependent fluorescence intensity decay in the target cells. The fits, which are excellent, yield the electroporation-induced fluorescence loss at steady state and the mass transfer rate through the electroporated cell membrane. Steady-state fluorescence loss ranged approximately from 0 to about 80% (based on the fluorescence intensity before electroporation). For the cells having a loss of thiol-ThioGlo 1 fluorescence intensity greater than 10% and mass transfer rate greater than 0.03 s(-1), EGFP fluorescence is observed after 24 h. The EGFP fluorescence is increased at 48 h. With a loss smaller than 10% and a mass transfer rate smaller than 0.03 s(-1), no EGFP fluorescence is detected. Thus, transfection success is closely related to the small molecule mass transport dynamics as indicated by the loss of fluorescence from thiol-ThioGlo 1 conjugates. The EGFP expression is weaker than bulk lipid-mediated transfection, as indicated by the EGFP fluorescence intensities. However, the success with the single-cell approach is considerably greater than lipid-mediated transfection.

Spatial distribution and extent of electroporation by strong internal shock in intact structurally normal and chronically infarcted rabbit hearts.

Although life-saving, a strong internal defibrillation shock may temporarily or permanently damage the heart via disruption of cell membranes (electroporation). Spatial extent of electroporation in intact, normal, or infarcted hearts has not been investigated. In this study, shock-induced electroporation in intact rabbit hearts with and without chronic (>4 weeks) left ventricular myocardial infarction (MI) was characterized. A coil shock electrode was inserted in the right ventricle of Langendorff-perfused hearts. One truncated exponential monophasic shock (+300 V, 8 ms) was delivered by a 150 microF capacitor clinical defibrillator while the heart was perfused with membrane-impermeant dye propidium iodide (PI). The heart was sectioned transversely, and uptake of PI into ventricular myocardium through electropores was quantified. Histological evaluation was performed via Masson's trichrome staining. PI accumulation was minimal in the control (n = 3) and MI (n = 3) hearts without shock. Following shock delivery, (1) in control (n = 5) and MI (n = 5) hearts, electroporation mostly occurred near the shock electrode and was longitudinally distributed along the active region of the shock electrode; (2) in MI group, electroporation was significantly increased (P < 0.05) in the surviving anterior epicardial layers of the infarcted region; and (3) between the control and MI groups, the overall extent of electroporation was similar. Shock-induced electroporation was spatially dependent on the location and dimension of the active region of the shock electrode. The overall extent of electroporation in the MI heart was comparable with the control heart, but the surviving anterior epicardial layers in the infarcted region were more susceptible to electroporation.