This study introduces the use of high-frequency pulsed electric fields for tissue electroporation. Through the development of finite element models and the use of analytical techniques, electroporation with rectangular, bipolar pulses is investigated. The electric field and temperature distribution along with the associated transmembrane potential development are considered in a heterogeneous skin fold geometry. Results indicate that switching polarity on the nanosecond scale near the charging time of plasma membranes can greatly improve treatment outcomes in heterogeneous tissues. Specifically, high-frequency fields ranging from 500 kHz to 1 MHz are best suited to penetrate epithelial layers without inducing significant Joule heating, and cause electroporation in underlying cells.

Theoretical Considerations of Tissue Electroporation With High-Frequency Bipolar Pulses

Pulsed electric fields (PEFs) have emerged as an ideal cardiac ablation modality. At present numerous clinical trials in humans are exploring PEF as an ablation strategy for both atrial and ventricular arrhythmias, with early data showing significant promise. As this is a relatively new technology there is limited understanding of its principles and biophysics. Importantly, PEF biophysics and principles are starkly different to current energy modalities (radiofrequency and cryoballoon). Given the relatively novel nature of PEFs, this review aims to provide an understanding of the principles and biophysics of PEF ablation. The goal is to enhance academic research and ultimately enable optimization of ablation parameters to maximize procedure success and minimize risk. 

https://academic.oup.com/humrep/article-pdf/37/7/1414/44386163/deac096.pdf

OUP accepted manuscript

Electroporation is a long-established technique used to deliver molecules to cells. Most in vivo electroporation protocols entail applying square-wave, or monotonically-decreasing pulses but relatively few have explored the use of pulsed ac fields. This study measures the efficiency of electroporation in human kidney embryonal cells, using pulsed ac electric fields of peak amplitude 30-200 kV m(-1). The results indicate that optimum electroporation efficiencies of up to 70% can be achieved using pulses at frequencies of 20-160 kHz. Increasing the field strength results in higher electroporation efficiency, but also increases cell kill. This study confirms that efficient electroporation may be achieved using pulsed ac fields. This finding raises the possibility of a wider range of clinical and laboratory applications based on ac technology and avoiding the use of invasive needle electrodes.

http://iopscience.iop.org/article/10.1088/0031-9155/53/17/019/pdf

Measurement of the efficiency of cell membrane electroporation using pulsed ac fields

Electroporation of Jurkat T-lymphoma human cells was investigated using 10-MHz continuous waves and benchmarked against that at 100 kHz. Both cell poration and cell death were simultaneously monitored by fluorescence microscopy, and found to occur under approximately four times higher voltages at 10 MHz than that at 100 kHz. This weaker-than-expected increase in poration threshold could be explained by detailed analysis of the distributed effect often ignored in electroporation studies.

Distributed Effect in High-Frequency Electroporation of Biological Cells

Gigahertz transverse electromagnetic (GTEM) transmission cells have been previously used to experimentally study exposure of biological cells to ultra-wideband (UWB), monopolar, electromagnetic pulses. Using finite-difference time-domain (FDTD) simulations we examine the time-dependent electric field waveforms and energy dose spatial distributions within a finite volume of biological cell culture medium during these experiments. The simulations show that when one or more flasks containing cell culture media are placed inside the GTEM cell, the uniform fields of the empty GTEM cell are significantly perturbed. The fields inside the cell culture medium, representing the fields to which the biological cells are exposed, are no longer monopolar and are spatially highly nonuniform. These effects result from a combination of refraction and distortion of the incident wave, combined with excitation of resonant eigenmodes within the cell culture medium volume. The simulations show that these distortions of the incident waveform may be mitigated by supporting the sample on a high permittivity pedestal and modifying the incident waveform to more closely approximate a Gaussian pulse. Under all simulated conditions,the estimated maximum temperature rises are completely negligible, ensuring that any experimentally observed unusual cell function or histopathology can be associated with nonthermal effects

/pdf/fdtd-analysis-of-a-gigahertz-tem-cell-for-ultra-wideband-3z0pqyn110.pdf

FDTD analysis of a gigahertz TEM cell for ultra-wideband pulse exposure studies of biological specimens

Experiments have been performed to investigate the nonthermal response of biological cells to pulsed, high-power (/spl sim/GW/m/sup 3/), radiofrequency (RF) radiation. Effects of 25-kHz RF-modulated-unipolar pulses, 20-kHz bipolar RF pulses, and 13.56-MHz bipolar RF pulses have been evaluated on nonexcitable COS-1 (African green monkey kidney) and electrically excitable N1E-115 (mouse brain neuroblastoma) cell electroporation. Trypan blue exclusion has been used to determine electroporation induced cell death; 4',6-Diamidino-2-phenylindole hydrochloride (DAPI) staining of DNA has been used to measure cell membrane permeabilization during electroporation. Experiments using 25-kHz modulation of a unipolar pulse indicate that the greatest effect of RF modulation on survivability and electroporation efficiency occurs at electric fields where a majority of the cells are killed in the absence of RF modulation: 1.6-2 kV/cm. RF modulation at these voltages protects the cells from electroporation induced death but it also reduces the membrane permeabilization. Bipolar RF pulses with no dc offset did not cause electroporation at 20 kHz or 13.56 MHz. RF power, pulselengths, and sample volumes used in experiments allowed only negligible amounts of sample heating. A simplified circuit analysis of an electrical model of the cell predicts that the transition frequency for transmembrane voltage in a bipolar, sinusoidal external electric field is 1 MHz.

Effect of pulsed, high-power radiofrequency radiation on electroporation of mammalian cells

Summary form only given. A series of experiments has been performed to determine the effectiveness of radiofrequency (RF) and ultrawideband electric fields for electroporation of cells, since these fields can be launched or focused by a waveguide or antenna. In a first series of experiments at moderate electric fields, we compared the electroporation response of electrically excitable and non-excitable cells with two cell lines: the N1E-115 murine neuroblastoma and the COS-1 African green monkey kidney fibroblast. Four electric field modalities were used; each exposure consisted of a train of five pulses at 1-s intervals. Square (DC) pulses (1-ms) were used for comparison to the RF-modulated fields. Bursts (2-ms) of unipolar RF at 25 kHz, bipolar RF at 20 kHz, and bipolar RF at 13.56 MHz were applied to cells to observe the frequency dependence of the electroporation response. Applied electric fields ranged from 0-2.0 kV/cm. Electroporation and cell killing by DC pulses and unipolar RF pulses were consistent with earlier results. For field strengths up to 2 kV/cm, 2-ms unipolar RF bursts produced both less killing and less permeabilization than 1-ms DC pulses. The reduced killing of the RF bursts resulted in higher electroporation yields for these exposures at some electric field strengths. For bipolar RF bursts (no DC offset), 2-ms bursts had no measurable effect on cell killing or permeabilization at field strengths up to 1.5 kV/cm at 20 kHz or 13.56 MHz. The most recent experiments at UM have tested the effects of bipolar, pulsed, high electric fields (45-180 kV/cm) on electroporation and apoptosis of Jurkat T lymphocytes. The electrical pulses have fast-risetime (<2 ns) and in a mismatched configuration exhibit a bipolar-pulse train of some 70 ns total duration, with spectral content up to 1.2 GHz. Single pulses as well as trains of up to 200 pulses at 1 Hz repetition frequency were applied. At peak electric fields of 45-180 kV/cm, single pulses induce apoptosis, whereas multiple pulses (5-200) kill most cells.

Frequency dependence of electroporation of mammalian cells by pulsed high power radiofrequency and ultrawideband radiation

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

L.H. Gates

Author Tools

Chat about Author

Papers

Effect of pulsed, high-power radiofrequency radiation on electroporation of mammalian cells

Frequency dependence of electroporation of mammalian cells by pulsed high power radiofrequency and ultrawideband radiation