Determining tissue conductivity in tissue ablation by nanosecond pulsed electric fields

Edwin A Oshin; Siqi Guo; Chunqi Jiang

doi:10.1016/j.bioelechem.2021.107949

Determining tissue conductivity in tissue ablation by nanosecond pulsed electric fields

Bioelectrochemistry. 2022 Feb:143:107949. doi: 10.1016/j.bioelechem.2021.107949. Epub 2021 Sep 20.

Authors

Edwin A Oshin¹, Siqi Guo², Chunqi Jiang³

Affiliations

¹ Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA; Department of Electrical and Computer Engineering, Old, Dominion University, Norfolk, VA, USA.
² Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA.
³ Frank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA; Department of Electrical and Computer Engineering, Old, Dominion University, Norfolk, VA, USA. Electronic address: cjiang@odu.edu.

Abstract

Nanosecond pulsed electric field (nsPEF) causes the permeabilization of the cell membrane and has been used to non-thermally treat cancerous tissues. As increased permeabilization in membranes were reported to be accompanied by impedance changes, the ablation effect of nsPEF on tissues can be monitored via the changes in tissue conductivity. In this study, effects of nsPEF on biological tissues were evaluated by determining the conductivities of potato and 4 T1-luc breast tumor tissues ex vivo from a murine model subjected to multiple 100-ns, 1-10 kV pulses. Using a four-needle electrode system with a calibrated electrode constant of 1.1 ± 0.1 cm, the conductivities of tissues was determined from both the network-analyzer measurement, before and after treatment, and voltage-current measurement in real-time. The conductivity of the potato tissue was measured for a frequency range of 0.1-3 MHz, and it increased with increasing pulse number and voltage amplitude. The conductivity of the tumor tissue was also observed to increase with pulse number and pulse voltage over a similar frequency range. In addition, the linear correlation between the ablation area in a treated potato tissue and the conductivity change in the tissue suggests that conductivity analysis of biological tissue under treatment could be a fast and sensitive approach to evaluate the effectiveness of a nsPEF treatment.

Keywords: Bioimpedance; Cancer therapy; Electropermeabilization; Electroporation; Impedance measurement.

MeSH terms

Electroporation*

Grants and funding

R21 CA229939/CA/NCI NIH HHS/United States