Bioelectric effects of intense nanosecond pulses

Karl H. Schoenbach, Barbara Hargrave, Ravindra P. Joshi, Juergen F. Kolb, Richard Nuccitelli, Christopher Osgood, Andrei Pakhomov, Michael Stacey, R. James Swanson, Jody A. White, Shu Xiao, Jue Zhang, Stephen J. Beebe, Peter F. Blackmore, E. Stephen Buescher

Research output: Contribution to journalArticlepeer-review

281 Scopus citations

Abstract

Electrical models for biological cells predict that reducing the duration of applied electrical pulses to values below the charging time of the outer cell membrane (which is on the order of 100 ns for mammalian cells) causes a strong increase in the probability of electric field interactions with intracellular structures due to displacement currents. For electric field amplitudes exceeding MV/m, such pulses are also expected to allow access to the cell interior through conduction currents flowing through the permeabilized plasma membrane. In both cases, limiting the duration of the electrical pulses to nanoseconds ensures only nonthermal interactions of the electric field with subcellular structures. This intracellular access allows the manipulation of cell functions. Experimental studies, in which human cells were exposed to pulsed electric fields of up to 300 kV/cm amplitude with durations as short as 3 ns, have confirmed this hypothesis and have shown that it is possible to selectively alter the behavior and/or survival of cells. Observed nanosecond pulsed effects at moderate electric fields include intracellular release of calcium and enhanced gene expression, which could have long term implications on cell behavior and function. At increased electric fields, the application of nanosecond pulses induces a type of programmed cell death, apoptosis, in biological cells. Cell survival studies with 10 ns pulses have shown that the viability of the cells scales inversely with the electrical energy density, which is similar to the "dose" effect caused by ionizing radiation. On the other hand, there is experimental evidence that, for pulses of varying durations, the onset of a range of observed biological effects is determined by the electrical charge that is transferred to the cell membrane during pulsing. This leads to an empirical similarity law for nanosecond pulse effects, with the product of electric field intensity, pulse duration, and the square root of the number of pulses as the similarity parameter. The similarity law allows one not only to predict cell viability based on pulse parameters, but has also been shown to be applicable for inducing platelet aggregation, an effect which is triggered by internal calcium release. Applications for nanosecond pulse effects cover a wide range: from a rather simple use as preventing biofouling in cooling water systems, to advanced medical applications, such as gene therapy and tumor treatment. Results of this continuing research are leading to the development of wound healing and skin cancer treatments, which are discussed in some detail.

Original languageEnglish
Pages (from-to)1088-1107
Number of pages20
JournalIEEE Transactions on Dielectrics and Electrical Insulation
Volume14
Issue number5
DOIs
StatePublished - Oct 2007

Keywords

  • Apoptosis
  • Bioelectrics
  • Nanosecond pulsed electric fields
  • Platelet aggregation
  • Pulse power
  • Subcellular effects
  • Tumor treatment
  • Wound healing

Fingerprint

Dive into the research topics of 'Bioelectric effects of intense nanosecond pulses'. Together they form a unique fingerprint.

Cite this