Open Access. Powered by Scholars. Published by Universities.®

Biochemistry, Biophysics, and Structural Biology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Bioelectrics Publications

2015

Articles 1 - 6 of 6

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Picosecond To Terahertz Perturbation Of Interfacial Water And Electropermeabilization Of Biological Membranes, P. Thomas Vernier, Zachary A. Levine, Ming-Chak Ho, Shu Xiao, Iurii Semenov, Andrei G. Pakhomov Jan 2015

Picosecond To Terahertz Perturbation Of Interfacial Water And Electropermeabilization Of Biological Membranes, P. Thomas Vernier, Zachary A. Levine, Ming-Chak Ho, Shu Xiao, Iurii Semenov, Andrei G. Pakhomov

Bioelectrics Publications

Non-thermal probing and stimulation with subnanosecond electric pulses and terahertz electromagnetic radiation may lead to new, minimally invasive diagnostic and therapeutic procedures and to methods for remote monitoring and analysis of biological systems, including plants, animals, and humans. To effectively engineer these still-emerging tools, we need an understanding of the biophysical mechanisms underlying the responses that have been reported to these novel stimuli. We show here that subnanosecond (≤500 ps) electric pulses induce action potentials in neurons and cause calcium transients in neuroblastoma-glioma hybrid cells, and we report complementary molecular dynamics simulations of phospholipid bilayers in electric fields in which …

Go to article

Gadolinium Modifies The Cell Membrane To Inhibit Permeabilization By Nanosecond Electric Pulses, Elena C. Gianulis, Andrei G. Pakhomov Jan 2015

Gadolinium Modifies The Cell Membrane To Inhibit Permeabilization By Nanosecond Electric Pulses, Elena C. Gianulis, Andrei G. Pakhomov

Bioelectrics Publications

Lanthanide ions are the only known blockers of permeabilization by electric pulses of nanosecond duration (nsEP), but the underlying mechanisms are unknown. We employed timed applications of Gd3+ before or after nsEP (600-ns, 20 kV/cm) to investigate the mechanism of inhibition, and measured the uptake of the membrane-impermeable YO-PRO-1 (YP) and propidium (Pr) dyes. Gd3+ inhibited dye uptake in a concentration-dependent manner. The inhibition of Pr uptake was always about 2-fold stronger. Gd3+ was effective when added after nsEP, as well as when it was present during nsEP exposure and removed afterward. Pores formed by nsEP in …

Go to article

In Situ Oh Generation From O2- And H2o2 Plays A Critical Role In Plasma Induced Cell Death, Dehui Xu, Dingxing Liu, Biqing Wang, Chen Chen, Zeyu Chen, Dong Li, Yanjie Yang, Hailan Chen, Michael G. Kong Jan 2015

In Situ Oh Generation From O2- And H2o2 Plays A Critical Role In Plasma Induced Cell Death, Dehui Xu, Dingxing Liu, Biqing Wang, Chen Chen, Zeyu Chen, Dong Li, Yanjie Yang, Hailan Chen, Michael G. Kong

Bioelectrics Publications

Reactive oxygen and nitrogen species produced by cold atmospheric plasma (CAP) are considered to be the most important species for biomedical applications, including cancer treatment. However, it is not known which species exert the greatest biological effects, and the nature of their interactions with tumor cells remains ill-defined. These questions were addressed in the present study by exposing human mesenchymal stromal and LP-1 cells to reactive oxygen and nitrogen species produced by CAP and evaluating cell viability. Superoxide anion (O2-) and hydrogen peroxide (H2O2) were the two major species present in plasma, but their …

Go to article

Electroporation Of Mammalian Cells By Nanosecond Electric Field Oscillations And It's Inhibition By The Electric Field Reversal, Elena C. Gianulis, Jimo Lee, Chunqi Jiang, Shu Xiao, Bennet L. Ibey, Andrei G. Pakhomov Jan 2015

Electroporation Of Mammalian Cells By Nanosecond Electric Field Oscillations And It's Inhibition By The Electric Field Reversal, Elena C. Gianulis, Jimo Lee, Chunqi Jiang, Shu Xiao, Bennet L. Ibey, Andrei G. Pakhomov

Bioelectrics Publications

The present study compared electroporation efficiency of bipolar and unipolar nanosecond electric field oscillations (NEFO). Bipolar NEFO was a damped sine wave with 140 ns first phase duration at 50% height; the peak amplitude of phases 2-4 decreased to 35%, 12%, and 7% of the first phase. This waveform was rectified to produce unipolar NEFO by cutting off phases 2 and 4. Membrane permeabilization was quantified in CHO and GH3 cells by uptake of a membrane integrity marker dye YO-PRO-1 (YP) and by the membrane conductance increase measured by patch clamp. For treatments with 1-20 unipolar NEFO, at 9.6-24 …

Go to article

Introduction To Fifth Special Issue On Electroporation-Based Technologies And Treatments, Damijan Miklavčič, Lluis M. Mir, P. Thomas Vernier Jan 2015

Introduction To Fifth Special Issue On Electroporation-Based Technologies And Treatments, Damijan Miklavčič, Lluis M. Mir, P. Thomas Vernier

Bioelectrics Publications

This special issue of the Journal of Membrane Biology contains reports on recent developments in the field of electroporation by participants in the International Workshop and Postgraduate Course on Electroporation-Based Technologies and Treatments held in November 2014 in Ljubljana. This was the eighth session of what is now an annual event, first organized in 2003.

Go to article

Diffuse, Non-Polar Electropermeabilization And Reduced Propidium Uptake Distinguish The Effect Of Nanosecond Electric Pulses, Iurii Semenov, Christian W. Zemlin, Olga N. Pakhomova, Shu Xiao, Andrei G. Pakhomov Jan 2015

Diffuse, Non-Polar Electropermeabilization And Reduced Propidium Uptake Distinguish The Effect Of Nanosecond Electric Pulses, Iurii Semenov, Christian W. Zemlin, Olga N. Pakhomova, Shu Xiao, Andrei G. Pakhomov

Bioelectrics Publications

Ca2+ activation and membrane electroporation by 10-ns and 4-ms electric pulses (nsEP and msEP) were compared in rat embryonic cardiomyocytes. The lowest electric field which triggered Ca2+ transients was expectedly higher for nsEP (36 kV/cm)than forms EP (0.09 kV/cm) but the respective doses were similar (190 and460 mJ/g). At higher intensities, both stimuli triggered prolonged firing in quiescent cells. An increase of basal Ca2+ level by N10 nM in cells with blocked voltage-gated Ca2+ channels and depleted Ca2+ depot occurred at 63 kV/cm (nsEP) or 0.14 kV/cm (msEP) and was regarded as electroporation threshold. These …

Go to article