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Bioelectrics Publications

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Articles 31 - 60 of 104

Full-Text Articles in Cell and Developmental Biology

Excitation And Injury Of Adult Ventricular Cardiomyocytes By Nano- To Millisecond Electric Shocks, Iurii Semenov, Sergey Grigoryev, Johanna U. Neuber, Christian W. Zemlin, Olga N. Pakhomova, Maura Casciola, Andrei G. Pakhomov Jan 2018

Excitation And Injury Of Adult Ventricular Cardiomyocytes By Nano- To Millisecond Electric Shocks, Iurii Semenov, Sergey Grigoryev, Johanna U. Neuber, Christian W. Zemlin, Olga N. Pakhomova, Maura Casciola, Andrei G. Pakhomov

Bioelectrics Publications

Intense electric shocks of nanosecond (ns) duration can become a new modality for more efficient but safer defibrillation. We extended strength-duration curves for excitation of cardiomyocytes down to 200 ns, and compared electroporative damage by proportionally more intense shocks of different duration. Enzymatically isolated murine, rabbit, and swine adult ventricular cardiomyocytes (VCM) were loaded with a Ca2+ indicator Fluo-4 or Fluo-5N and subjected to shocks of increasing amplitude until a Ca2+ transient was optically detected. Then, the voltage was increased 5-fold, and the electric cell injury was quantified by the uptake of a membrane permeability marker dye, propidium …


Nano-Pulse Stimulation For The Treatment Of Pancreatic Cancer And The Changes In Immune Profile, Sigi Guo, Niculina I. Burcus, James Hornef, Yu Jing, Chunqi Jiang, Richard Heller, Stephen J. Beebe Jan 2018

Nano-Pulse Stimulation For The Treatment Of Pancreatic Cancer And The Changes In Immune Profile, Sigi Guo, Niculina I. Burcus, James Hornef, Yu Jing, Chunqi Jiang, Richard Heller, Stephen J. Beebe

Bioelectrics Publications

A Pancreatic cancer is a notorious malignant neoplasm with an extremely poor prognosis. Current standard of care is rarely effective against late-stage pancreatic cancer. In this study, we assessed nanopulse stimulation (NPS) as a local treatment for pancreatic cancer in a syngeneic mouse Pan02 pancreatic cancer model and characterized corresponding changes in the immune profile. A single NPS treatment either achieved complete tumor regression or prolonged overall survival in animals with partial tumor regression. While this is very encouraging, we also explored if this local ablation effect could also result in immune stimulation, as was observed when NPS led to …


Enhanced Electric Pulse Technology For The Ablation Of Pancreatic Cancer, Siqi Guo, Niculina I. Burcus, Chelsea M. Edelblute, James Hornef, Chunqi Jiang, Karl Schoenbach, Richard Heller, Stephen J. Beebe Jan 2018

Enhanced Electric Pulse Technology For The Ablation Of Pancreatic Cancer, Siqi Guo, Niculina I. Burcus, Chelsea M. Edelblute, James Hornef, Chunqi Jiang, Karl Schoenbach, Richard Heller, Stephen J. Beebe

Bioelectrics Publications

Electric pulse based technology has been developed and studied as a non-thermal ablation method for local control of pancreatic cancer. Irreversible electroporation (IRE) has shown a significant survival benefit for local advanced pancreatic cancer in clinical trials. However, incomplete ablation with local recurrence and major complications limit the potential of this new technology. We have developed an integrated moderate heating electric pulse delivery system which consists of controllable tumor heating, multi-parameter monitoring and electric pulse delivery. The impedance of tumor is greatly decreased after moderate heating at 42°C for 1–2 min, which does not cause any cell death. Moderate heating …


Nanosecond Electric Pulses Differentially Affect Inward And Outward Currents In Patch Clamped Adrenal Chromaffin Cells, Lisha Yang, Gale L. Craviso, P. Thomas Vernier, Indira Chatterjee, Normand Leblanc Jul 2017

Nanosecond Electric Pulses Differentially Affect Inward And Outward Currents In Patch Clamped Adrenal Chromaffin Cells, Lisha Yang, Gale L. Craviso, P. Thomas Vernier, Indira Chatterjee, Normand Leblanc

Bioelectrics Publications

This study examined the effect of 5 ns electric pulses on macroscopic ionic currents in whole-cell voltage-clamped adrenal chromaffin cells. Current-voltage (I-V) relationships first established that the early peak inward current was primarily composed of a fast voltage-dependent Na+ current (INa), whereas the late outward current was composed of at least three ionic currents: a voltage-gated Ca2+ current (ICa), a Ca2+-activated K+ current (IK(Ca)), and a sustained voltage-dependent delayed rectifier K+ current (IKV). A constant-voltage step protocol was next used to monitor peak inward and late …


Anti-Proliferative Role Of Recombinant Lethal Toxin Of Bacillus Anthracis On Primary Mammary Ductal Carcinoma Cells Revealing Its Therapeutic Potential, Rekha Khandia, Bramhadev Pattnaik, Katherikamem Rajukumar, Atul Pateriya, Sandeep Bhatia, Harshad Murugkar, Anil Prakash, Hare Krishna Pradhan, Kildeep Dhama, Ashol Munjal, Sunil K. Joshi Jan 2017

Anti-Proliferative Role Of Recombinant Lethal Toxin Of Bacillus Anthracis On Primary Mammary Ductal Carcinoma Cells Revealing Its Therapeutic Potential, Rekha Khandia, Bramhadev Pattnaik, Katherikamem Rajukumar, Atul Pateriya, Sandeep Bhatia, Harshad Murugkar, Anil Prakash, Hare Krishna Pradhan, Kildeep Dhama, Ashol Munjal, Sunil K. Joshi

Bioelectrics Publications

Bacillus anthracis secretes three secretary proteins; lethal factor (LF), protective antigen (PA) and edema factor (EF). The LF has ability to check proliferation of mammary tumors, chiefly depending on mitogen activated protein kinase (MAPK) signaling pathway. Evaluation of therapeutic potential of recombinant LF (rLF), recombinant PA (rPA) and lethal toxin (rLF + rPA = LeTx) on the primary mammary ductal carcinoma cells revealed significant (p < 0.01) reduction in proliferation of tumor cells with mean inhibition indices of 28.0 ±1.37% and 19.6 ± 1.47% respectively. However, treatment with rPA alone had no significant anti-proliferative effect as evident by low mean inhibition index of 3.4 ± 3.87%. The higher inhibition index observed for rLF alone as compared to LeTx is contrary to the existing knowledge on LF, which explains the requirement of PA dependent endocytosis for its enzymatic activity. Therefore, the plausible existence of PA independent mode of action of LF including direct receptor mediated endocytosis or modulation of signal transduction cascade via unknown means is hypothesized. In silico protein docking analysis of other cellular receptors for any plausibility to play the role of receptor for LF revealed c-Met receptor showing strongest affinity for LF (H bond = 19; Free energy = …


Nanosecond Pulsed Electric Field Induced Changes In Cell Surface Charge Density, Diganta Dutta, Xavier-Lewis Palmer, Anthony Asmar, Michael Stacey, Shizhi Qian Jan 2017

Nanosecond Pulsed Electric Field Induced Changes In Cell Surface Charge Density, Diganta Dutta, Xavier-Lewis Palmer, Anthony Asmar, Michael Stacey, Shizhi Qian

Bioelectrics Publications

This study reports that the surface charge density changes in Jurkat cells with the application of single 60 nanosecond pulse electric fields, using atomic force microscopy. Using an atomic force microscope tip and Jurkat cells on silica in a 0.01 M KCl ionic concentration, we were able to measure the interfacial forces, while also predicting surface charge densities of both Jurkat cell and silica surfaces. The most important finding is that the pulsing conditions varyingly reduced the cells' surface charge density. This offers a novel way in which to examine cellular effects of pulsed electric fields that may lead to …


Cell Electrosensitization Exists Only In Certain Electroporation Buffers, Janja Dermol, Olga N. Pakhomova, Andrei G. Pakhomov, Damijan Miklavčič Jan 2016

Cell Electrosensitization Exists Only In Certain Electroporation Buffers, Janja Dermol, Olga N. Pakhomova, Andrei G. Pakhomov, Damijan Miklavčič

Bioelectrics Publications

Electroporation-induced cell sensitization was described as the occurrence of a delayed hypersensitivity to electric pulses caused by pretreating cells with electric pulses. It was achieved by increasing the duration of the electroporation treatment at the same cumulative energy input. It could be exploited in electroporation-based treatments such as electrochemotherapy and tissue ablation with irreversible electroporation. The mechanisms responsible for cell sensitization, however, have not yet been identified. We investigated cell sensitization dynamics in five different electroporation buffers. We split a pulse train into two trains varying the delay between them and measured the propidium uptake by fluorescence microscopy. By fitting …


Cytosolic Dna Sensor Upregulation Accompanies Dna Electrotransfer In B16.F10 Melanoma Cells, Katarina Znidar, Masa Bosnjak, Maja Cemazar, Loree C. Heller Jan 2016

Cytosolic Dna Sensor Upregulation Accompanies Dna Electrotransfer In B16.F10 Melanoma Cells, Katarina Znidar, Masa Bosnjak, Maja Cemazar, Loree C. Heller

Bioelectrics Publications

In several preclinical tumor models, antitumor effects occur after intratumoral electroporation, also known as electrotransfer, of plasmid DNA devoid of a therapeutic gene. In mouse melanomas, these effects are preceded by significant elevation of several proinflammatory cytokines. These observations implicate the binding and activation of intracellular DNA-specific pattern recognition receptors or DNA sensors in response to DNA electrotransfer. In tumors, IFN β mRNA and protein levels significantly increased. The mRNAs of several DNA sensors were detected, and DAI, DDX60, and p204 tended to be upregulated. These effects were accompanied with reduced tumor growth and increased tumor necrosis. In B16. F10 …


The Cytotoxic Synergy Of Nanosecond Electric Pulses And Low Temperature Leads To Apoptosis, Claudia Muratori, Andrei G. Pakhomov, Elena C. Gianulis, Sarah D. Jensen, Olga N. Pakhomova Jan 2016

The Cytotoxic Synergy Of Nanosecond Electric Pulses And Low Temperature Leads To Apoptosis, Claudia Muratori, Andrei G. Pakhomov, Elena C. Gianulis, Sarah D. Jensen, Olga N. Pakhomova

Bioelectrics Publications

Electroporation by nanosecond electric pulses (nsEP) is an emerging modality for tumor ablation. Here we show the efficient induction of apoptosis even by a non-toxic nsEP exposure when it is followed by a 30-min chilling on ice. This chilling itself had no impact on the survival of U-937 or HPAF-II cells, but caused more than 75% lethality in nsEP-treated cells (300 ns, 1.8-7 kV/cm, 50-700 pulses). The cell death was largely delayed by 5-23 hr and was accompanied by a 5-fold activation of caspase 3/7 (compared to nsEP without chilling) and more than 60% cleavage of poly-ADP ribose polymerase (compared …


Effect Of Twisted Fiber Anisotropy In Cardiac Tissue On Ablation With Pulsed Electric Fields, Fei Xie, Christian W. Zemlin Jan 2016

Effect Of Twisted Fiber Anisotropy In Cardiac Tissue On Ablation With Pulsed Electric Fields, Fei Xie, Christian W. Zemlin

Bioelectrics Publications

Background: Ablation of cardiac tissue with pulsed electric fields is a promising alternative to current thermal ablation methods, and it critically depends on the electric field distribution in the heart.

Methods: We developed a model that incorporates the twisted anisotropy of cardiac tissue and computed the electric field distribution in the tissue. We also performed experiments in rabbit ventricles to validate our model. We find that the model agrees well with the experimentally determined ablation volume if we assume that all tissue that is exposed to a field greater than 3 kV/cm is ablated. In our numerical analysis, we considered …


Radio-Frequency Plasma Polymerized Biodegradable Carrier For In Vivo Release Of Cis-Platinum, Sudhir Bhatt, Fatemeh Valamanesh, Jerome Pulpytel, Rea Lo Dico, Aliby Baiyukha, Iman Al-Dybiat, Marc Pocard, Farzaneh Arefi-Khonsari, Massoud Mirshahi Jan 2016

Radio-Frequency Plasma Polymerized Biodegradable Carrier For In Vivo Release Of Cis-Platinum, Sudhir Bhatt, Fatemeh Valamanesh, Jerome Pulpytel, Rea Lo Dico, Aliby Baiyukha, Iman Al-Dybiat, Marc Pocard, Farzaneh Arefi-Khonsari, Massoud Mirshahi

Bioelectrics Publications

A low pressure plasma process based on plasma deposition has been used to develop a drug delivery strategy. In this study, a drug delivery system based on different layers of plasma co-polymerized Poly ε-caprolactone-Polyethylene glycol (PCL-PEG) co-polymers was deposited on biocompatible substrates. Cis-platinum (118 μgm/cm2) was used as an anti-cancer drug and incorporated for local delivery of the chemotherapeutic agent. The co-polymer layers and their interaction with cancer cells were analyzed by scanning electron microscopy. Our study showed that the plasma-PCL-PEG coated cellophane membranes, in which the drug, was included did not modify the flexibility and appearance of …


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 …


Dose-Dependent Atp Depletion And Cancer Cell Death Following Calcium Electroporation, Relative Effect Of Calcium Concentration And Electric Field Strength, Emilie Louise Hansen, Esin Bengisu Sozer, Stefania Romeo, Stine Krog Frandsen, P. Thomas Vernier, Julie Gehl Jan 2015

Dose-Dependent Atp Depletion And Cancer Cell Death Following Calcium Electroporation, Relative Effect Of Calcium Concentration And Electric Field Strength, Emilie Louise Hansen, Esin Bengisu Sozer, Stefania Romeo, Stine Krog Frandsen, P. Thomas Vernier, Julie Gehl

Bioelectrics Publications

Background: Electroporation, a method for increasing the permeability of membranes to ions and small molecules, is used in the clinic with chemotherapeutic drugs for cancer treatment (electrochemotherapy). Electroporation with calcium causes ATP (adenosine triphosphate) depletion and cancer cell death and could be a novel cancer treatment. This study aims at understanding the relationship between applied electric field, calcium concentration, ATP depletion and efficacy. Methods: In three human cell lines — H69 (small-cell lung cancer), SW780 (bladder cancer), and U937 (leukaemia), viability was determined after treatment with 1, 3, or 5 mM calcium and eight 99 μs pulses with 0.8, 1.0, …


Effects Of Nanosecond Pulse Electric Fields On Cellular Elasticity, Diganta Dutta, Anthony Asmar, Michael W. Stacey Jan 2015

Effects Of Nanosecond Pulse Electric Fields On Cellular Elasticity, Diganta Dutta, Anthony Asmar, Michael W. Stacey

Bioelectrics Publications

We investigated the effects of a single 60 nanosecond pulsed electric field (nsPEF) of low (15 kV/cm) and high (60 kV/cm) field strengths on cellular morphology and membrane elasticity in Jurkat cells using fluorescent microscopy and atomic force microscopy (AFM). We performed force displacement measurements on cells using AFM and calculated the Young's modulus for membrane elasticity. Differential effects were observed depending upon pulsing conditions. We found that a single nsPEF of low field strength did not induce any apparent cytoskeletal breakdown and had minor morphological changes. Interestingly, force measurements and calculation of Young's modulus showed a significant decrease in …


Mechanisms Of Nanosecond Pulsed Electric Field (Nspef)-Induced Cell Death In Cells And Tumors, Stephen J. Beebe Jan 2015

Mechanisms Of Nanosecond Pulsed Electric Field (Nspef)-Induced Cell Death In Cells And Tumors, Stephen J. Beebe

Bioelectrics Publications

The evolution of pulse power technology from high power physics to biology and medicine places nanosecond pulsed electric fields (nsPEFs) in positions for in vitro and in vivo applications as non-ligand agonists that not only bypass plasma membrane receptors for induction of intracellular signaling pathways, but also bypass intracellular oncogenic impasses to induce cell death by regulated mechanisms. Based on work reviewed here, a likely scenario for cell and tumor demise includes nsPEF-induced permeabilization of the plasma membrane, Ca2+ influx, dissipation of the mitochondrial membrane potential, which is likely due to events beyond permeabilization of the inner mitochondrial membrane, cytochrome …


Presence And Localization Of Pro-And Mature Forms Of Biglycan And Decorin In Human Costal Cartilage Derived From Chest Wall Deformities, Anthony Asmar, A. Werner, R. E. Kelly Jr., A. Fecteau, Michael W. Stacey Jan 2015

Presence And Localization Of Pro-And Mature Forms Of Biglycan And Decorin In Human Costal Cartilage Derived From Chest Wall Deformities, Anthony Asmar, A. Werner, R. E. Kelly Jr., A. Fecteau, Michael W. Stacey

Bioelectrics Publications

Costal cartilage is a type of hyaline cartilage that forms rod-like structures that connect the ribs to the sternum. The most common chest wall deformities, pectus excavatum and pectus carinatum involved efective costal cartilage resulting in sternal displacement. Costal cartilage is not widely studied leaving little insight into possible factors involved in the pathogenesis of these pectus deformities. This study focused on the presence and distribution of two important regulators of collagen fibrillogenesis and organization, biglycan and decorin. Immunohistochemical analysis of transverse cross sections of normal and deformed costal cartilage revealed that biglycan and decorin mainly localized in the territorial …


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.


Enhanced Breast Cancer Therapy With Nspefs And Low Concentrations Of Gemcitabine, Shan Wu, Jinsong Guo, Wendong Wei, Jue Zhang, Jing Fang, Stephen J. Beebe Oct 2014

Enhanced Breast Cancer Therapy With Nspefs And Low Concentrations Of Gemcitabine, Shan Wu, Jinsong Guo, Wendong Wei, Jue Zhang, Jing Fang, Stephen J. Beebe

Bioelectrics Publications

Chemotherapy either before or after surgery is a common breast cancer treatment. Long-term, high dose treatments with chemotherapeutic drugs often result in undesirable side effects, frequent recurrences and resistances to therapy. The anti-cancer drug, gemcitabine (GEM) was used in combination with pulse power technology with nanosecond pulsed electric fields (nsPEFs) for treatment of human breast cancer cells in vitro. Two strategies include sensitizing mammary tumor cells with GEM before nsPEF treatment or sensitizing cells with nsPEFs before GEM treatment.Breast cancer cell lines MCF-7 and MDA-MB-231 were treated with 250 65 ns-duration pulses and electric fields of 15, 20 or 25 …


Pkc-Dependent Phosphorylation Of Enos At T495 Regulates Enos Coupling And Endothelial Barrier Function In Response To G(+) -Toxins, Feng Chen, Sanjiv Kumar, Yanfang Yu, Saurabh Aggarwal, Christine Gross, Yusi Wang, Trinad Chakraborty, Alexander D. Verin, John D. Catravas, Rudolf Lucas, Stephen M. Black, David J. R. Fulton Jul 2014

Pkc-Dependent Phosphorylation Of Enos At T495 Regulates Enos Coupling And Endothelial Barrier Function In Response To G(+) -Toxins, Feng Chen, Sanjiv Kumar, Yanfang Yu, Saurabh Aggarwal, Christine Gross, Yusi Wang, Trinad Chakraborty, Alexander D. Verin, John D. Catravas, Rudolf Lucas, Stephen M. Black, David J. R. Fulton

Bioelectrics Publications

Gram positive (G(+)) infections make up similar to 50% of all acute lung injury cases which are characterized by extensive permeability edema secondary to disruption of endothelial cell (EC) barrier integrity. A primary cause of increased permeability are cholesterol-dependent cytolysins (CDCs) of G(+)-bacteria, such as pneumolysin (PLY) and listeriolysin-O (LLO) which create plasma membrane pores, promoting Ca2+-influx and activation of PKC alpha. In human lung microvascular endothelial cells (HLMVEC), pretreatment with the nitric oxide synthase (NOS) inhibitor, ETU reduced the ability of LLO to increase microvascular cell permeability suggesting an endothelial nitric oxide synthase (eNOS)-dependent mechanism. LLO stimulated superoxide production …


Novel Mechanism Of Attenuation Of Lps-Induced Nf-Kappab Activation By The Heat Shock Protein 90 Inhibitor, 17-N-Allylamino-17-Demethoxygeldanamycin, In Human Lung Microvascular Endothelial Cells, Gagan S. Thangjam, Christiana Dimitropoulou, Atul D. Joshi, Nektarios Barabutis, Mary C. Shaw, Yevgeniy Kovalenkov, Christopher M. Wallace, David J. Fulton, Vijay Patel, John D. Catravas May 2014

Novel Mechanism Of Attenuation Of Lps-Induced Nf-Kappab Activation By The Heat Shock Protein 90 Inhibitor, 17-N-Allylamino-17-Demethoxygeldanamycin, In Human Lung Microvascular Endothelial Cells, Gagan S. Thangjam, Christiana Dimitropoulou, Atul D. Joshi, Nektarios Barabutis, Mary C. Shaw, Yevgeniy Kovalenkov, Christopher M. Wallace, David J. Fulton, Vijay Patel, John D. Catravas

Bioelectrics Publications

Heat shock protein (hsp) 90 inhibition attenuates NF-kappaB activation and blocks inflammation. However, the precise mechanism of NF-kappaB regulation by hsp90 in the endothelium is not clear. We investigated the mechanisms of hsp90 inhibition by 17-N-allylamino-17-demethoxygeldanamycin (17-AAG) on NF-kappaB activation by LPS in primary human lung microvascular endothelial cells. Transcriptional activation of NF-kappaB was measured by luciferase reporter assay, gene expression by real-time RT-PCR, DNA binding of transcription factors by chromatin immunoprecipitation assay, protein-protein interaction by coimmunoprecipitation/immunoblotting, histone deacetylase (HDAC)/histone acetyltransferase enzyme activity by fluorometry, and nucleosome eviction by partial microccocal DNase digestion. In human lung microvascular endothelial cells, 17-AAG-induced …


Cellular Regulation Of Extension And Retraction Of Pseudopod-Like Blebs Produced By Nanosecond Pulsed Electric Field, Mikhail A. Rassokhin, Andrei G. Pakhomov Jan 2014

Cellular Regulation Of Extension And Retraction Of Pseudopod-Like Blebs Produced By Nanosecond Pulsed Electric Field, Mikhail A. Rassokhin, Andrei G. Pakhomov

Bioelectrics Publications

Recently we described a new phenomenon of anodotropic pseudopod-like blebbing in U937 cells exposed to nanosecond pulsed electric field (nsPEF). In Ca2+ -free buffer such exposure initiates formation of pseudopod-like blebs (PLBs), protrusive cylindrical cell extensions that are distinct from apoptotic and necrotic blebs. PLBs nucleate predominantly on anode-facing cell pole and extend toward anode during nsPEF exposure. Bleb extension depends on actin polymerization and availability of actin monomers. Inhibition of intracellular Ca2+ , cell contractility, and RhoA produced no effect on PLB initiation. Meanwhile, inhibition of WASP by wiskostatin causes dose-dependent suppression of PLB growth. Soon after …


Dielectric Characterization Of Coastal Cartilage Chondrocytes, Michael W. Stacey, Ahmet C. Sabuncu, Ali Beskok Jan 2014

Dielectric Characterization Of Coastal Cartilage Chondrocytes, Michael W. Stacey, Ahmet C. Sabuncu, Ali Beskok

Bioelectrics Publications

BACKGROUND: Chondrocytes respond to biomechanical and bioelectrochemical stimuli by secreting appropriate extracellular matrix proteins that enable the tissue to withstand the large forces it experiences. Although biomechanical aspects of cartilage are well described, little is known of the bioelectrochemical responses. The focus of this study is to identify bioelectrical characteristics of human costal cartilage cells using dielectric spectroscopy.

METHODS: Dielectric spectroscopy allows non-invasive probing of biological cells. An in house computer program is developed to extract dielectric properties of human costal cartilage cells from raw cell suspension impedance data measured by a microfluidic device. The dielectric properties of chondrocytes are …


Basic Features Of A Cell Electroporation Model: Illustrative Behavior For Two Very Different Pulses, Reuben S. Son, Kyle C. Smith, Thiruvallur R. Gowrishankar, P. Thomas Vernier, James C. Weaver Jan 2014

Basic Features Of A Cell Electroporation Model: Illustrative Behavior For Two Very Different Pulses, Reuben S. Son, Kyle C. Smith, Thiruvallur R. Gowrishankar, P. Thomas Vernier, James C. Weaver

Bioelectrics Publications

Science increasingly involves complex modeling. Here we describe a model for cell electroporation in which membrane properties are dynamically modified by poration. Spatial scales range from cell membrane thickness (5 nm) to a typical mammalian cell radius (10 μm), and can be used with idealized and experimental pulse waveforms. The model consists of traditional passive components and additional active components representing nonequilibrium processes. Model responses include measurable quantities: transmembrane voltage, membrane electrical conductance, and solute transport rates and amounts for the representative "long" and "short" pulses. The long pulse-1.5 kV/cm, 100 μs-evolves two pore subpopulations with a valley at ~5 …


Cancellation Of Cellular Responses To Nanoelectroporation By Reversing The Stimulus Polarity, Andrei G. Pakhomov, Iurii Semenov, Shu Xiao, Olga N. Pakhomova, Betsy Gregory, Karl H. Schoenbach Jan 2014

Cancellation Of Cellular Responses To Nanoelectroporation By Reversing The Stimulus Polarity, Andrei G. Pakhomov, Iurii Semenov, Shu Xiao, Olga N. Pakhomova, Betsy Gregory, Karl H. Schoenbach

Bioelectrics Publications

Nanoelectroporation of biomembranes is an effect of high-voltage, nanosecond-duration electric pulses (nsEP). It occurs both in the plasma membrane and inside the cell, and nanoporated membranes are distinguished by ion-selective and potential-sensitive permeability. Here we report a novel phenomenon of bioeffects cancellation that puts nsEP cardinally apart from the conventional electroporation and electrostimulation by milli- and microsecond pulses. We compared the effects of 60- and 300-ns monopolar, nearly rectangular nsEP on intracellular Ca2+mobilization and cell survival with those of bipolar 60 + 60 and 300 + 300 ns pulses. For diverse endpoints, exposure conditions, pulse numbers (1-60), and …


Heat Shock Protein 90 Inhibitors Prevent Lps-Induced Endothelial Barrier Dysfunction By Disrupting Rhoa Signaling, Atul D. Joshi, Christiana Dimitropoulou, Gagan S. Thangjam, Connie Snead, Sara Feldman, Nektarios Barabutis, David Fulton, Yali Hou, Sanjiv Kumar, Vijay Patel, Boris Gorshkov, Alexander D. Verin, Stephen M. Black, John D. Catravas Jan 2014

Heat Shock Protein 90 Inhibitors Prevent Lps-Induced Endothelial Barrier Dysfunction By Disrupting Rhoa Signaling, Atul D. Joshi, Christiana Dimitropoulou, Gagan S. Thangjam, Connie Snead, Sara Feldman, Nektarios Barabutis, David Fulton, Yali Hou, Sanjiv Kumar, Vijay Patel, Boris Gorshkov, Alexander D. Verin, Stephen M. Black, John D. Catravas

Bioelectrics Publications

Permeability of the endothelial monolayer is increased when exposed to the bacterial endotoxin LPS. Our previous studies have shown that heat shock protein (Hsp) 90 inhibitors protect and restore LPS-mediated hyperpermeability in bovine pulmonary arterial endothelial cells. In this study, we assessed the effect of Hsp90 inhibition against LPS-mediated hyperpermeability in cultured human lung microvascular endothelial cells (HLMVECs) and delineated the underlying molecular mechanisms. We demonstrate that Hsp90 inhibition is critical in the early phase, to prevent LPS-mediated hyperpermeability, and also in the later phase, to restore LPS-mediated hyperpermeability in HLMVECs. Because RhoA is a well known mediator of endothelial …


Electrochemotherapy: From The Drawing Board Into Medical Practice, Damijan Miklavčič, Barbara Mali, Bor Kos, Richard Heller, Gregor Serša Jan 2014

Electrochemotherapy: From The Drawing Board Into Medical Practice, Damijan Miklavčič, Barbara Mali, Bor Kos, Richard Heller, Gregor Serša

Bioelectrics Publications

Electrochemotherapy is a local treatment of cancer employing electric pulses to improve transmembrane transfer of cytotoxic drugs. In this paper we discuss electrochemotherapy from the perspective of biomedical engineering and review the steps needed to move such a treatment from initial prototypes into clinical practice. In the paper also basic theory of electrochemotherapy and preclinical studies in vitro and in vivo are briefly reviewed. Following this we present a short review of recent clinical publications and discuss implementation of electrochemotherapy into standard of care for treatment of skin tumors, and use of electrochemotherapy for other targets such as head and …


Introduction To Fourth Special Issue On Electroporation-Based Technologies And Treatments, Damijan Miklavčič, Lluis M. Mir, P. Thomas Vernier Jan 2014

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

Bioelectrics Publications

This fourth special electroporation-based technologies and treatments issue of the Journal of Membrane Biology contains reports on recent developments in the field of electroporation by participants in the 7th International Workshop and Postgraduate Course on electroporation based technologies and treatments (EBTT 2013) held in Ljubljana, November 17–23, 2013. The 65 participants included faculty members, invited lecturers, special guests, and young scientists, and students from 16 countries. In addition to lectures on the fundamentals, this year’s sessions included talks on microbial inactivation by pulsed electric fields, modeling of intracellular electroporation, electroporation in food processing, and electrotransfer-facilitated DNA vaccination.


Applications For Pulse Power Using Nanosecond Pulsed Electric Fields (Nspefs) In Cell Biology And Cancer Treatment, Stephen J. Beebe Jan 2013

Applications For Pulse Power Using Nanosecond Pulsed Electric Fields (Nspefs) In Cell Biology And Cancer Treatment, Stephen J. Beebe

Bioelectrics Publications

No abstract provided.


Induction Of Cell Death Mechanisms And Apoptosis By Nanosecond Pulsed Electric Fields (Nspefs), Stephen J. Beebe, Nova M. Sain, Wei Ren Jan 2013

Induction Of Cell Death Mechanisms And Apoptosis By Nanosecond Pulsed Electric Fields (Nspefs), Stephen J. Beebe, Nova M. Sain, Wei Ren

Bioelectrics Publications

Pulse power technology using nanosecond pulsed electric fields (nsPEFs) offers a new stimulus to modulate cell functions or induce cell death for cancer cell ablation. New data and a literature review demonstrate fundamental and basic cellular mechanisms when nsPEFs interact with cellular targets. NsPEFs supra-electroporate cells creating large numbers of nanopores in all cell membranes. While nsPEFs have multiple cellular targets, these studies show that nsPEF-induced dissipation of DeltaPsim closely parallels deterioration in cell viability. Increases in intracellular Ca2+ alone were not sufficient for cell death; however, cell death depended of the presence of Ca2+. When both events occur, cell …


Cell Responses Without Receptors And Ligands, Using Nanosecond Pulsed Electric Fields (Nspefs), Stephen J. Beebe Jan 2013

Cell Responses Without Receptors And Ligands, Using Nanosecond Pulsed Electric Fields (Nspefs), Stephen J. Beebe

Bioelectrics Publications

No abstract provided.