Electroporation-Induced Cell Modifications Detected with THz Time-Domain Spectroscopy
- 275 Downloads
Electroporation (electropermeabilization) increases the electrical conductivity of biological cell membranes and lowers transport barriers for normally impermeant materials. Molecular simulations suggest that electroporation begins with the reorganization of water and lipid head group dipoles in the phospholipid bilayer interface, driven by an externally applied electric field, and the evolution of the resulting defects into water-filled, lipid pores. The interior of the electroporated membrane thus contains water, which should provide a signature for detection of the electropermeabilized state. In this feasibility study, we use THz time-domain spectroscopy, a powerful tool for investigating biomolecular systems and their interactions with water, to detect electroporation in human cells subjected to permeabilizing pulsed electric fields (PEFs). The time-domain response of electroporated human monocytes was acquired with a commercial THz, time-domain spectrometer. For each sample, frequency spectra were calculated, and the absorption coefficient and refractive index were extracted in the frequency range between 0.2 and 1.5 THz. This analysis reveals a higher absorption of THz radiation by PEF-exposed cells, with respect to sham-exposed ones, consistent with the intrusion of water into the cell through the permeabilized membrane that is presumed to be associated with electroporation.
KeywordsElectroporation THz time-domain spectroscopy Human monocytes MM-6 cells Pulsed electric fields Water content
The support and advice of Dr. Antonio Pepe (CNR-IREA, Napoli) in the analysis of THz time-domain spectroscopy data is gratefully acknowledged.
- 2.Marty M, Sersa G, Garbay JR, Gehl J, Collins CG, Snoj M, et al. Electrochemotherapy—an easy, highly effective and safe treatment of cutaneous and subcutaneousmetastases: results of ESOPE (European Standard Operating Procedures of Electrochemotherapy) study. European journal of cancer 4, 3 (2006).CrossRefGoogle Scholar
- 3.Golberg A, Sack M, Teissie J, Pataro G, Pliquett U, Saulis G, et al. Energy-efficient biomass processing with pulsed electric fields for bioeconomy and sustainable development. Biotechnology for Biofuels 9, (2016).Google Scholar
- 9.Hansen EL, Sozer EB, Romeo S, Frandsen SK, Vernier PT, Gehl J Dose-Dependent ATP Depletion and Cancer Cell Death following Calcium Electroporation, Relative Effect of Calcium Concentration and Electric Field Strength (vol 10, e0122973, 2015). PloS one 10, (2015).Google Scholar
- 14.Azan A, Untereiner V, Gobinet C, Sockalingum GD, Breton M, Piot O, et al. Demonstration of the Protein Involvement in Cell Electropermeabilization using Confocal Raman Microspectroscopy. Sci Rep-Uk 7, (2017).Google Scholar
- 22.Kinosita K, Tsong TY Hemolysis of Human Erythrocytes by a Transient Electric-Field. P Natl Acad Sci USA 74, 1923 (1977).Google Scholar