Moreover, an increase of internal Ca 2+ concentration (especially in the case of electroporation with nanosecond electric pulses, nsEP) can be a result of its release from internal stores and amplification with more complex Ca 2+ pathways, such as calcium-induced calcium release and store-operated (capacitive) calcium entry. However, Ca 2+ can also be transported through voltage-gated calcium channels (VGCC) or other channels. Due to the small size of Ca 2+ ions compared to other EP detection dyes such as propidium iodide (PI) or YO-PRO-1, this method is considered very sensitive and can detect smaller pores, such as those of nanometer size that emerge in EP with ns pulses, as well as lower levels of membrane electroporation. Monitoring the uptake of calcium ions (Ca 2+) is a very convenient way of evaluating the extent of EP, because calcium concentration in cells is kept very low (around 100 nM) due to its signaling role. The influx of ions through a permeabilized plasma membrane can also be an indicator of EP. However, molecular mechanisms related to cell membrane permeability and transport post pulse are yet to be elucidated, since the pore closure time in molecular dynamics simulations is several orders of magnitude shorter than experimentally determined membrane resealing times. The transport takes place during and after the pulse, the latter being dominant at least in the case of small molecules. The transport of molecules through permeabilized plasma membrane occurs presumably through aqueous pores that form in the process of electroporation. Electroporation for drug delivery can be controlled by choosing appropriate electric pulse parameters for specific cells and tissues, as well as molecules to be delivered, therefore it is of great importance to thoroughly explore the phenomenon. As a drug delivery method, electroporation has already been used for the delivery of chemotherapeutics to treat tumors (electrochemotherapy), transdermal drug delivery, gene electrotransfer for gene therapy and DNA vaccination, and for delivery of CRISPR-Cas9 components for gene editing. Since it is a physical method, it bypasses the potential safety issue of viral vectors. Įlectroporation can also be used for intracellular drug delivery. Reversible and irreversible EP is nowadays used in numerous applications in medicine, food technology, and biotechnology. With moderate electric fields, cells recover after electroporation and remain viable (reversible EP), however, with stronger electric fields or longer pulse duration, cells do not recover from the damage and they die (irreversible EP).
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Increased plasma membrane permeability allows transmembrane transport of otherwise impermeant molecules into cells. 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.Įxposure of cells to electric pulses of adequate amplitude and durations leads to transient increase in their plasma membrane permeability and the phenomenon is termed electroporation (EP).
![wavesurfer 422 wavesurfer 422](https://i.ebayimg.com/images/g/8vYAAOSwahFe0IjE/s-l300.jpg)
With shorter 100 ns pulses, the asymmetry is not observed. 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. 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.
![wavesurfer 422 wavesurfer 422](https://i.ytimg.com/vi/iTDhuyszeHE/maxresdefault.jpg)
However, asymmetry reported was inconsistent and inconclusive-in different reports it was either preferentially anodal or cathodal. Uptake of molecules after electroporation are the greatest at poles of cells facing electrodes and is often asymmetrical. Orientation of cells in electric field is important for electroporation and, consequently, for transport of molecules through permeabilized plasma membrane. Electroporation (EP) is one of the successful physical methods for intracellular drug delivery, which temporarily permeabilizes plasma membrane by exposing cells to electric pulses.