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... • If there are nodules located elsewhere, only these nodules will be eligible for treatment by ECT. [32] Hematology If platelets <70000/μL then hematological opinion regarding the risk of bleeding versus the benefit of the therapy. The clinician can then make an informed decision. ...
... If the nodules of the patient are all deep (more than 1 cm below the skin) nodules, the patient is not eligible for treatment by ECT. [32] Biochemistry If using intravenous bleomycin then creatinine should be <150 μmol/l to ensure adequate renal clearance. [32] Operating Modality Anesthesia Lay a rectangular infiltration of local anesthetic (lidocaine, 2%, with adrenaline 0.5%) around the area to be treated, by injecting along four lines so that the nodule is 'fenced in' by local anesthetic, so that pain transmission is completely blocked. ...
... [32] Biochemistry If using intravenous bleomycin then creatinine should be <150 μmol/l to ensure adequate renal clearance. [32] Operating Modality Anesthesia Lay a rectangular infiltration of local anesthetic (lidocaine, 2%, with adrenaline 0.5%) around the area to be treated, by injecting along four lines so that the nodule is 'fenced in' by local anesthetic, so that pain transmission is completely blocked. [33] Small cutaneous tumors may be anesthetized by local infiltration of lidocaine just below the tumor, however, still covering the area of electroporation. ...
... Cette approche consiste à rajouter au modèle électrique de la cellule un modèle de transport des molécules à l'extérieur et dans la cellule qui tient compte du degré de perméabilité de la membrane cellulaire. Cette perméabilité est augmentée par l'application du champ électrique mais le temps caractéristique de l'état de haute perméabilité est plus long que la durée de l'état de haute conductivité, ce qui permet d'expliquer à la fois le caractère transitoire de l'état conducteur des membranes (quelques microsecondes selon les travaux de Zimmermann et al. [9]) et la longue durée de l'état perméable des membranes, plusieurs minutes comme observé par L.M. Mir [71]. Cette partie est précisément décrite en Section 4.2 du Chapitre I. ...
... In the 70's, it has been observed that electric shock may change transiently the membrane porosity, allowing the entrance of usually non-permeant molecules into the cytoplasm. This phenomenon, called electroporation or electropermeabilization has then been studied for cancer treatments, by coupling a cytotoxic drug -such as bleomycin or cisplatin -with high voltage pulses [71]. Electrochemotherapy is now used in more than 40 Cancer Institutes in Europe for cutaneaous tumors and several clinical studies are driven for deep located tumors. ...
... • The modeling is based on the existence of pores, while such pores have never been observed in experiments. • The model identifies the high conducting state of the membrane and the electropermeabilization, while it has been reported by Benz et al. [9] that the conducting state lasts a few microseconds after the pulse for planar bilayer, while the permeable state of the membrane lasts several minutes according to Mir et al [71]. For all these reasons, we choose to develop new models of electropermeabilization, which avoid these drawbacks. ...
This thesis consists of a synthetized presentation of my research in order to get the French diploma
“Habilitation à diriger des recherches”.
It is organized into four chapters that constitute the four main topics I focused on since I got my
permanent position at Inria, in September 2008. These research axes have been developed within the
framework of the Inria team MC2, leaded by T. Colin. This thesis is the result of collaborations with
colleagues of Bordeaux and elsewhere (Karlsruhe, Lyon, Rennes, Villejuif) as well as with Phd students and
postdoctoral fellows I co-supervised. Therefore I choose to use we to present the results.
Chapter 1 is devoted to cell electropermeabilization modeling. Electropermeabilization (also called
electroporation) is a significant increase in the electrical conductivity and permeability of cell membrane
that occurs when pulses of large amplitude (a few hundred volts per centimeter) are applied to the cells:
due to the electric field, the cell membrane is permeabilized, and then nonpermeant molecules can easily
enter the cell cytoplasm by transport (active and passive) through the electropermeabilized membranes. If
the pulses are too long, too numerous or if their amplitude is too high, the cell membrane is irreversibly
destroyed and the cells are killed. However, if the pulse duration is sufficiently short (a few milliseconds or
a few microseconds, depending on the pulse amplitude), the cell membrane reseals within several tens of
minutes: such a reversible electroporation preserves the cell viability and is used in electrochemotherapy to
vectorize the drugs into cancer cells. In Chapter 1, I present the modeling we derived in tight collaboration
with biologists, namely the L.M. Mir’s group at the IGR, which is one of the world’s leader in this field, as
well as the numerical schemes and the comparisons of the numerical simulations with the experimental data.
Interestingly, our modeling that uncouples electric and permeable behaviours of the cell membrane makes it
possible to explain the strange observation of cell desensitization, that has been reported very recently by A.
Silve et al. [100]. This desensitization consists of a less degree of cell permeabilization after a few successive
electric pulses than for the same number of pulses but with a delay between each electric pulse delivery. This
phenomenon is counter-intuitive and was not predictable by the previous models of the literature.
Chapter II is devoted to cell migration modeling and more precisely to the endothelial cell migration on
micropatterned polymers. The goal is to provide models based on the experimental data in order to describe
the cell migration on micropatterned polymers. The long–term goal is to provide tools for the optimization
of such a migration, which is crucial in tissue engineering. We develop a continuous model of Patlak-KellerSegel
type, which makes it possible to provide qualitative results in accordance with the experiments, and
we analyse the mathematical properties of this model. Then, we provide an agent-based model, based on
a classical mechanics approach. Strikingly, this very simple model has been quantitatively fitted with the
experimental data provided by our colleagues of the biological institute IECB, in terms of cell orientation
and cell migration. I conclude the chapter by on-going works on the invadopodia modeling, in collaboration
with T. Suzuki from Osaka University and M. Ohta from Tokyo University of Sciences. Chapter III is devoted to a very recent activity I started in 2013 on tumor growth models, therefore
this chapter is based on only one submitted preprint. I present the results on ductal carcinoma growth
modeling. Originally confined to the milk duct, these breast cancers may become invasive and agressive after
the degradation of the duct membrane, and the main features of our model is to describe the membrane
degradation thanks to a non-linear Kedem–Katchalsky condition that describes the jump of pressure across
the duct membrane. More precisely, the membrane permeability is given as a non-linear function of specific
enzymes (MMPs) that degrade the membrane. We also provide some possible explanation of heterogeneity
of tumor growth by modeling the influence of the micro-environment and the emergence of specific cell types.
I eventually conclude by Chapter IV, which consists of a few advances in asymptotics analysis for domains
that are singular or asymptotically singular, in the following of my PhD thesis. The results can be split into
two parts: first I present approximate transmission conditions through a periodically rough thin layer, and
how we characterize the influence of such a layer on the polarization tensor in the sense of Capdeboscq and
Voeglius [19]. Then I focus on the numerical treatment of the eddy current problem in domains with corner
singularity.
Each chapter is organized into a description of the results, a few perspectives for forthcoming research
and a list of the published papers related to the topic of the chapter. Before presenting the results we
obtained, I give in the next part a brief summary in French
... As electroporation creates a direct passage through the membrane barrier, non-permeant drugs in particular gain easier access to the cytosol by electroporation (15). One such drug is the hydrophilic, charged cytotoxic agent bleomycin (6,16). ...
... When cells or tissue are exposed to direct current for a brief period of time (ls to ms) electroporation can occur. The externally applied electric field induces transmembrane potential changes that result in dielectric breakdown of the membrane once a certain (23,24,(26)(27)(28)32,98) threshold is surpassed (3,15,18). The membrane is temporarily destabilized (1,2) and it is generally accepted that some sort of permeation structure or ''pore'' is created (4). ...
... The membrane is temporarily destabilized (1,2) and it is generally accepted that some sort of permeation structure or ''pore'' is created (4). Through these permeation structures, molecules (in the range up to 30,000 Da MW(3)) that normally are nonpermeant can freely enter the cell by diffusion (15). Larger charged molecules, like DNA, can also enter the cells through these large permeation structures, but this needs to be aided by an electrophoretic effect of the pulses on the DNA (13,19). ...
Over the last decade a new cancer treatment modality, electrochemotherapy, has emerged. By using short, intense electric pulses that surpass the capacitance of the cell membrane, permeabilization can occur (electroporation). Thus, molecules that are otherwise non-permeant can gain direct access to the cytosol of cells in the treated area.A highly toxic molecule that does not usually pass the membrane barrier is the hydrophilic drug bleomycin. Once inside the cell, bleomycin acts as an enzyme creating single- and double-strand DMA-breaks. The cytotoxicity of bleomycin can be augmented several 100-fold by electroporation. Drug delivery by electroporation has been in experimental use for cancer treatment since 1991.This article reviews 11 studies of electrochemotherapy of malignant cutaneous or subcutaneous lesions, e.g., metastases from melanoma, breast or head- and neck cancer. These studies encompass 96 patients with altogether 411 malignant tumours. Electroporation was performed using plate or needle electrodes under local or general anaesthesia. Bleomycin was administered intratumourally or intravenously prior to delivery of electric pulses. The rates of complete response (CR) after once-only treatments were between 9 and 100% depending on the technique used. The treatment was well tolerated and could be performed on an out-patient basis.
... Another context in which IRE has been studied is in the delayed cell damage in high voltage accidents [2,66] and the post-electric-shock arrhythmias during defibrillation [67]. Lee showed that electrical injury is attributed to thermal damage as well as IRE in superposition. ...
... Electroporation is a technique that uses micro to milliseconds electric pulses to create pores in the cell membrane, thus allowing molecules that, due to their physical and/or chemical properties, would normally not be able to cross the cell membrane, to enter the cell [26][27][28][29][30]. The opening of pores in the cell membrane allows the chemotherapeutic agent to enter the cell at greater, more effective concentration and exert its cytotoxic action by killing the target cell [67,68,157]. However, if cells are unable to seal the pores formed because the electric field is maintained for longer times (i.e. when using a high number of pulses) cell death due to the loss of homeostatic mechanisms occurs. ...
Irreversible electroporation (IRE) is a minimally invasive and non-thermal technique in which an ultra-short pulse with high electric field has been found to be successful for ablation of certain tumor and cancer cells. As a mimic of biomembranes of cells, lipid membranes of giant unilamellar vesicles (GUVs), composed of dioleoylphosphatidylglycerol (DOPG) and dioleoylphosphatidylcholine (DOPC), with diameters equal or greater than 10 μm is currently used. In this regard, at first a microcontroller-based IRE technique is developed indigenously where a special purpose power supply is used to construct high voltage generator and a MOSFET (N-Channel Power MOSFET, SCILLC) based switching circuit is designed for generating square pulses with very high energy as required for electroporation. Then investigated the electro- deformation and pore formation of GUVs at constant tension induced by IRE signal. It is also observed the membrane fusion of GUVs induced by the IRE signal. The constant tension is induced on the GUVs at electric field strength 340V/cm with pulse width 200 µs. The pore formation in GUVs is increased with the increase of constant tension which supported the results of the mechanical tension-induced pore formation. The pore formation in the lipid membranes is explained by the classical theory of pore formation. These results provide important information for the mechanism of IRE-induced pore formation in biomembranes and lipid membranes. Therefore, optimization of various parameters of IRE technique is necessary for the study of pore formation in lipid membranes of GUVs.
... Research reveals that application of ultra-short high voltage pulses can also cause irreversible damage. Since the 1970s, the technique has found a wide range of applications in biology and medicine including gene transfection, gene therapy, vaccine delivery against viruses and electrochemotherapy of cancer [6][7][8][9][10][11][12][13][14][15] . ...
... It is an established method for delivery of drugs and DNA into biological cells both in vitro and in vivo including electrochemotherapy of tumors 6 and gene electro-transfer [16][17] . Advanced research in electroporation involved molecular transport experiments 18 and aims to understand the effects of electroporation using high intensity and very short duration electric pulses on cells and tissues [19][20][21][22] . ...
Electroporation or electropermeabilization is a biophysical process involving enhanced permeability of biological cell membrane due to the application of an electric field of very short duration. Since its inception in the early 1970’s, the technique has been utilized widely in biomedical research and applications including gene transfection and electrochemotherapy of cancer. Past theoretical models of cell electroporation considered approximations which made the predicted results very different from the experimental descriptions of poration, especially for electrochemotherapy applications. Present work is a theoretical formulation and numerical implementation of small molecule (Doxorubicin) uptake during electroporation of a mammalian cell with cholesterol-containing membrane. Here, we explore the effects of changes in membrane cholesterol content on electroporation pore dynamics and uptake of small molecules. © 2018 Indian Journal of Biochemistry & Biophysics. All rights reserved.
... When an electric field is applied to a cell or cell system, a uniform transmembrane potential (TMP) is induced on exposed cells. If the induced TMP is large enough, i.e., above the threshold value ,the cell membrane becomes permeabilized in a reversible process called electro permeabilization, thus allowing entrance of molecules that otherwise cannot easily cross the cell membrane [1]- [3]. Further increase of the electric field causes irreversible membrane permeabilization and cell death. ...
... The specific capacitance of the outer membrane was 3.29 microfarad. The capacitance of the nuclear membrane was assumed to be half that of the outer membrane because two lipid membranes comprise the nuclear envelope, whereas the outer membrane consists of only one [1]. Input voltages of magnitudes between 1.0 and 5V and 0.5 ms duration were used in the numerical study of electroporation. ...
report the computational simulation study for the characterization of multilayer dense osteoblast intra organelle membrane potential in different microelectrode. The response of a cell model at various frequencies and the effect of cell parameters, such as cell membrane resistance and capacitance, were studied. We show that at low frequencies—the intra organelle can be electro porated while at high frequencies, the induced potential can be much lower than that at low frequencies at same applied voltage for dense osteo cells .we also find out that the induced TMP of osteoblast cell depends not only on its radius and geometry of the microelectrode but also the resistances and capacitances of suspending medium, which effects the dielectric property of osteoblast cell. Keywordscell, Osteoblast cells, Simulation, Electroporation, cytoplasm, Nucleolus, Frequency Response, Intra-organelle potential.
... In fact this sensitivity to applied external electric field leads to a significant increase of transmembrane voltage [9,18]. Electroporation phenomena that is very important in medicine and biology is one of the results of permeability changing as well as the voltage of a membrane which is induced by an applied external electric field [1,5,8,19202122. In other hands the effects of electric fields on the cells and soft tissue is unclear yet293031. ...
... In other hands the effects of electric fields on the cells and soft tissue is unclear yet293031. Understanding the response of cells to DC and AC electric fields can help scientists and physicians to recognize normal cells and diseased [7,20] . Recently a lot of theoretical and experimental work has been done by scientist in this field. ...
Abstract
It is known that the electric field incurs effects on the living cells. Predicting the response of single cell or multilayer cells to induced alternative or static eclectic field has permanently been a challenge. In the present study a first order single cell with acute angle under the influence of external electric field is considered. The cell division stage or the special condition of reshaping is modelled with a cone being connected. In the case of cell divisions, anaphase, it can be considered with two cones that connected nose-to-nose. Each cone consists of two regions. The first is the membrane modelled with a superficial layer, and the second is cytoplasm at the core. A Laplace equation is written for this model and the distribution of its electric field is a sharp point in the single cell for which an acute angle model is calculated.
... In tissue electroporation, electrodes are inserted around the targeted tissue and electrical pulses are applied to permeabilize the cell membrane to macromolecules such as gene constructs in genetic engineering or cancer treatment drugs [1, 2]. For a specific set of voltage parameters (e.g. ...
... For a specific set of voltage parameters (e.g. pulse number, frequency, duration), the effect that the electric field has depends on the voltage gradients that develop across the individual cell [2]. Currently, there is no information during the application of the pulses regarding the extent and degree of electroporation. ...
INTRODUCTION In tissue electroporation, electrodes are inserted around the targeted tissue and electrical pulses are applied to permeabilize the cell membrane to macromolecules such as gene constructs in genetic engineering or cancer treatment drugs [1, 2]. For a specific set of voltage parameters (e.g. pulse number, frequency, duration), the effect that the electric field has depends on the voltage gradients that develop across the individual cell [2]. Currently, there is no information during the application of the pulses regarding the extent and degree of electroporation. Therefore, only the long-term consequences of the treatment can be determined, such as the cure or lack of cure of the cancer patient or the expression or the lack of expression of a gene. In this paper we demonstrate through experimental data and numerical models that electrical impedance tomography (EIT) can produce an image of the electroporated area. EXPERIMENTAL METHOD Biological tissues contain extracellular and intracellular electrolytes that are good conductors of electricity. During electroporation the cell membranes, which are electrically insulating, become permeable to chemical species including electrolytes. Our hypothesis is that if the cell membrane becomes increasingly permeable to ions during electroporation, the electrical impedance of a cell should change measurably. To quantify the impedance change of tissue during electroporation, we conducted experiments on excised rat liver slices approximately 2.5x2.0x0.25cm in size. For each experiment, a slice was placed onto a glass microscope slide surrounded by electrodes. The configuration consists of two separate sets of electrodes: one to administer the electroporation pulses and the other for detection. Experiments were conducted within 90 minutes from the time of death of the animal with the tissue stored in 0.9% NaCl at room temperature. The electroporation system is designed to supply eight 10ms squarewave pulses up to 500V/cm across the width of the tissue. This study provides data on the electrical impedance of liver before, during and after electroporation.
... LECTROCHEMOTHERAPY (ECT) is a local antitumor treatment that combines the administration of chemotherapeutic drugs with the local application of electric field pulses in order to transiently depolarize the cell membrane, making it permeable, and thus facilitate the delivery of non-permeant or low permeant drugs into cancer cells [1]- [3]. Among chemotherapeutic agents, bleomycin and cisplatin are the best potential candidates for ECT in cancer patients [4]. Once passed the cellular membrane and inside the cells, bleomycin induces single and double strand DNA breaks that lead to cell death [5]. ...
This paper presents a 40 GHz microwave biosensor used to monitor and characterize single cells (THP-1) subjected to electrochemotherapy and obtain an electronic signature of the treatment efficiency. This biosensor proposes a non-destructive and label-free technique that first allows, with the rapid measurement of single untreated cells in their culture medium, the extraction of two frequency-dependent dielectric parameters, the capacitance (C (f)) and the conductance (G (f)). Second, this technique can powerfully reveal the effects of a chemical membrane permeabilizing treatment (Saponin). At last, it permits us to detect, and predict, the potentiation of a molecule classically used in chemotherapy (Bleomycin) when combined with the application of electric pulses (principle of electrochemotherapy). Treatment-affected cells show a decrease in the capacitive and conductive contrasts, indicating damages at the cellular levels. Along with these results, classical biological tests are conducted. Statistical analysis points out a high correlation rate (R
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>
>0.97), which clearly reveals the reliability and efficacy of our technique and makes it an attractive technique for biology related researches and personalized medicine.
... In this research, we subjected yeast cells containing no prions and strong or weak prion variants to the pulsed electric field (PEF) of varied strength. PEF is proven to be an effective technique in drug delivery during electrochemotherapy [16][17][18], various microorganism transformation [19][20][21], electrofusion [22][23][24], as well as biocontrol of microorganisms in food protection and biotechnology [25][26][27]. It can provide a rapid and nonselective method for the elimination of various types of yeast. ...
Prions are misfolded, self-replicating, and transmissible proteins capable of causing different conditions that affect the brain and nervous system in humans and animals. Yeasts are the perfect model to study prion formation, dissemination, and the structure of protein aggregates. Yeast prions are related to stress resistance, cell fitness, and viability. Applying a pulsed electric field (PEF) as a factor capable of disintegrating the amyloid aggregates arises from the fact that the amyloid aggregates form via noncovalent bonds and stabilize via electrostatic interactions. In this research, we applied 2–26 kV/cm PEF delivered in sequences of 5 pulses of 1 ms duration to the Saccharomyces cerevisiae cell without prions and containing strong and weak variants of the [PSI+] prion (prion form of Sup35 translation termination factor). We determined that prions significantly increase cell survivability and resistance to PEF treatment. The application of PEF to the purified Sup35NM fibrils showed that the electric field causes significant reductions in the length of fibrils and the full disintegration of fibrils to Sup35 oligomers can be achieved in higher fields.
... A considerable increase in the cell membrane permeability to ions, molecules, and even macromolecules occurs during the period after the pores formation until their closure (Chen et al., 2006;Kandušer et al., 2006;Puc et al., 2003). Electroporation allows the incorporation of molecules inside the cells, which makes it an effective technique to introduce drugs and genes into living cells, especially in biotechnology and medicine fields (Kotnik et al., 2015;Mir, 2001). Electroporation was employed to develop genetic engineering techniques for LAB vector construction and has gained great interest in research development. ...
Lactic acid bacteria (LAB) have a long history of applications in the food industry for fermentation and preservation. This feature is due to their metabolic products that can improve the nutritional and sensory characteristics of foods as well as their antimicrobial compounds that contribute to extend the shelf life of food products. Some emerging technologies including pulsed electric fields (PEF), power ultrasound (US), high-pressure processing (HPP), ultraviolet (UV), and microwave (MW) have attracted great attention for their implementation in the food industry as mild processing technologies. They have the advantage of efficiently inactivating the microorganisms, along with maintaining the fresh attributes of the food products. When applied at a sub-lethal level, these technologies present the potential to enhance several processes, such as improved microbial growth and fermentation conditions, as well as modified metabolic properties of LAB. This review covers the characteristics of LAB and their applications in the food industry. It discusses the impacts of emerging technologies on these microorganisms, with a special focus on microbial inactivation, growth stimulation, and improvement of the beneficial features of LAB by emerging technologies.
... It uses electroporation, a physical drug delivery system, to deliver non-permeant or poorly permeant chemotherapeutic agents into the cells. 1 Among several clinically approved drugs that have been tested in preclinical studies, bleomycin and cisplatin have been demonstrated to be the most suitable drugs for clinical use of electrochemotherapy. [2][3][4][5] Exposure of cells to electric pulses increases cytotoxicity of bleomycin (8000 fold) and cisplatin (80 fold). 2,3 In vivo application of electric pulses to the tumours significantly potentiates antitumour effectiveness of bleomycin or cisplatin, given either intravenously 3,6 or intratumourally. ...
8047
Background: By applying brief, electric pulses, cell membranes can be transiently permeabilised (electroporation). This can be applied focally to tumors, enhancing the uptake of certain chemotherapeutic agents dramatically (electrochemotherapy). Methods: From 2003 to 2005, patients with cancer of any histological diagnosis and symptomatic metastases to skin or subcutis were accrued in four cancer centers. Patients had been offered standard treatment options previously. Primary endpoint was response. One treatment was performed in either general anesthesia or local anesthesia, depending on anatomical site, size and number of tumors. The Cliniporator (IGEA, Italy) was used to deliver electric pulses, with 3 different electrode types: 1) Plate electrodes, 2) Linear array needle electrodes 3) Hexagonal needle electrodes. Eight pulses of 100 μs were applied using 1) 1300 V/cm, 2 and 3) 1000 V/cm. Either intravenous bleomycin 15000 IU/M-2, or intratumoral injections of either bleomycin or cisplatinum, were administered prior to application of electric pulses to the tumors. Responses were documented through direct tumor measurement and digital photography. Results: 41 patients, with altogether 171 cutaneous metastases of malignant melanoma (98 nodules, 57 %), carcinoma or sarcoma were treated. Overall, 145 (84.8%) of the treated nodules responded (CR or PR), with CR in 126 of the nodules (73.7%). Negative response was observed in very low percentage of the treated nodules being either NC (10.5%) or PD (4.7%). Treatment of melanoma and non-melanoma nodules was equally successful. Treatment time per session (one or more nodules) was median 25 min (range 6–60). Intravenous and intratumoral administration of bleomycin, or cisplatinum yielded similar results. No significant toxicity was found, and 96% of patients reported they would agree to another treatment if indicated. Conclusions: Electrochemotherapy is an efficient, safe and simple palliative treatment of cutaneous and subcutaneous metastases of cancers of various histologies. Patient acceptance of treatment was excellent and 73.7% of nodules were in CR after one single treatment.
No significant financial relationships to disclose.
... Through the administration of properly tuned electric pulses, EP leads to reversible (as in ECT) or irreversible (as in IRE) cell membrane permeabilization. While in ECT, EP increases the uptake and activity of concomitant chemotherapy, in IRE it is applied as a standalone therapy which provokes irrecoverable cell imbalance [1][2][3][4][5][6]. ECT has been first standardized in 2006 and the currently adopted protocols in clinical practice include pre-determined standardized parameters [1,7]. ...
Tumor electroporation (EP) refers to the permeabilization of the cell membrane by means of short electric pulses thus allowing the potentiation of chemotherapeutic drugs. Standard plate adhesion 2D cell cultures can simulate the in vivo environment only partially due to lack of cell–cell interaction and extracellular matrix (ECM). In this study, we assessed a novel 3D scaffold for cell cultures based on hyaluronic acid and ionic-complementary self-assembling peptides (SAPs), by studying the growth patterns of two different breast carcinoma cell lines (HCC1569 and MDA-MB231). This 3D scaffold modulates cell shape and induces extracellular matrix deposit around cells. In the MDA-MB 231 cell line, it allows three-dimensional growth of structures known as spheroids, while in HCC1569 it achieves a cell organization similar to that observed in vivo. Interestingly, we were able to visualize the electroporation effect on the cells seeded in the new scaffold by means of standard propidium iodide assay and fluorescence microscopy. Thanks to the presence of cell–cell and cell–ECM interactions, the new 3D scaffold may represent a more reliable support for EP studies than 2D cancer cell cultures and may be used to test new EP-delivered drugs and novel EP protocols.
... There are some factors that affect the electroporation process such as electric field magnitude, pulse frequency, period, duration, pulse shape, number of electric pulses, and electric field distribution [11]. The electric field distribution and magnitude inside the tissue depend on electric pulse parameters and tissue properties, such as tissue electrical conductivity [12]. ...
An estimate of patient dose, patient size should be used to normalise the output dose of CT machine in the terms of volume CT dose index, CTDIvol. There are two metrics to characterise the patient size, i.e. the effective diameter (Deff) and the water-equivalent diameter (Dw). These two metrics could be estimated by patient age. However, to date, relationships between the age and head patient size (Deff and Dw) have not been established for the paediatric patients. The aim of this study was to establish the relationships between the age and head patient size (Deff and the Dw) as the basis for calculating the size-specific dose estimated (SSDE) for paediatric head CT examination. The data were retrospectively collected from serial images of the CT head in the DICOM file from one hundred and thirteen paediatric patients aged 0-17 years (63 male and 50 female patients) underwent head CT examinations. The patient's sizes (Deff and Dw) were calculated from the patient's images using the IndoseCT version 15a software. The Deff and Dw values were correlated with age of patients using regression analysis. It was found that patient size (Deff and Dw) correlated well with the age of the patient with R 2 more than 0.8. The size of the Dw is bigger than the Deff. The Deff values for male patients are 12.38 to 16.21 cm, and Dw values are 11.96 to 18.16 cm, respectively. For female patients, the values of Deff from 11.54 to 16.87 cm, and Dw range is from 11.60 to 17.86 cm, respectively.
... Electroporation was first (15). Medical use of reversible electroporation started 30 years ago with electrochemotherapy, which increases cell permeability to chemotherapeutics (16). Irreversible electroporation is the presumed mechanism behind direct current ablation, used in the 1980s (17) for arrhythmias before being supplanted by thermal ablation to circumvent issues such as barotrauma and inhomogeneous lesion formation. ...
... The effectiveness of this combined treatment led to the initiation of clinical trials for melanoma, basal cell carcinoma, neck squamous cell carcinoma, adenocarcinomas(65,66,(69)(70)(71)(72)(73)(74)(75)(76)(77)(78)(79). However, it should be stressed that our results demonstrate far better effect than those carried out with ECT in preclinical studies.Circumstantial evidence for the involvement of immunological and/or inflammatory mechanisms following high voltage ECT was also reported. ...
Book location: Jewish National & University Library, Jerusalem, Israel, SYSNO 2330852.
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Abstract.
Low electric field enhanced cancer therapy (LEFCT) is a novel method for
treating solid invasive metastasizing tumors in vivo by exposing them to the
action of low pulsed electric fields alone or in the presence of chemotherapeutic
agents in the extracellular compartment. In the latter case the method was
termed low electric field enhanced cancer chemotherapy (LEFCT-EC). This
approach is based on the previous findings in our laboratory that exposure of
cells in vitro to low unipolar pulses of electric fields in the range of 5 to 80 V/cm,
induces efficient uptake of macromolecules possessing molecular weights
between one and 2000 kDa via electric field induced endocytotic pathways. The
present study developed and pioneered the use of this method in-vivo on mouse
tumor models. It was explored whether the exposure of tumors to low pulsed
electric fields and chemotherapeutic agents, potentiated the anti tumor
effectiveness of the latter. The efficacy of LEFCT was tested against two mouse
malignant tumors consisting of melanoma (B16-F10.9) and breast carcinoma
(DA3). Electric stimulation (40 V/cm) was applied to 60-70 mm3 subcutaneous
tumors by percutaneously placed electrodes after intratumoral injection of
chemotherapy.
B16-F10.9 melanoma. Significant tumor size reduction, prolongation of
survival and cure of some of the animals were achieved using LEFCT with
cisplatin and taxol, (13.5% and 26% cure rate, respectively). C57BL/6 mice cured
by the low electric field enhanced chemotherapy with cisplatin and taxol, and
challenged with a tumorigenic dose of B16-F10.9 cells, lived significantly longer
(p<0.000004) than first time inoculated mice, and 23.5% of LEFCT with taxol
cured challenged mice did not develop tumors at all. The mean survival time of
challenged mice, previously cured either by LEFCT with cisplatin or by LEFCT
with taxol was 49±6 and 73±11 days, respectively, whereas first-time inoculated
normal mice had mean survival time 31±1 days. Spleen cells from the cured mice
that were inoculated together with B16-F10.9 cells inhibited the primary tumor
growth in normal mice. The expression of m-RNA of IL2, IL4 and IFN-gamma by
splenocytes of low electric field treated mice was higher than in the normal and
untreated tumor bearing mice. Histological analysis of tumor sections of LEFCTEC
treated mice revealed multiple necrotic areas, apoptosis and massive
infiltrates of T-lymphocytes and macrophages. Low voltage electrochemotherapy
with taxol was shown to be more effective, than surgical tumor ectomy with taxol.
These findings indicate that LEFCT-EC is an effective treatment of animals
bearing metastatic melanoma.
DA3 breast carcinoma. Application of low electric field alone (LEF)
resulted in a destruction of the primary tumor, prolongation of survival and a cure
rate of 30% of the treated mice. Treatments with low electric field combined with
bleomycin, but not taxol, were more effective than LEF alone. The cured BALB/c
mice were more resistant to challenge with a tumorigenic dose of DA3 cells than
first time inoculated mice (mean survival time of 47±2 days vs. 38±2 days,
respectively, p=0.01). Inoculation with DA3 cells simultaneously with splenocytes
from mice cured by LEF or LEF-chemotherapy, inhibited growth of the primary
tumor and increased the survival of inoculated animals, as comparable to those,
which received DA3 cells with splenocytes from normal mice. FACS analysis of
splenocytes showed that the proportion of CD3, CD4, CD8 and CD19 cells
decreased in the tumor bearing mice, while nearly normal values were regained
in the LEF/LEF-chemotherapy treated animals. Histological examination of the
lungs of mice with DA3 tumors revealed diffused metastases in untreated mice,
while metastatic foci in the lungs of LEF or LEF-chemotherapy treated mice had
a capsule composed of connective tissue fibers and an immune cell infiltrate. RTPCR
analysis of spleen cells revealed high m-RNA expression of IL2 and IL6 in
all tumor bearing mice, as compared to normal mice. Yet in the LEFchemotherapy
group the level of both cytokines was lower than in either LEF or
chemotherapy groups.
These findings indicate that low voltage pulsed electric field can efficiently
destroy the primary tumors of chemotherapy resistant malignancies, such as
DA3, and induce an immune response that might arrest the development of
metastatic lesions. When viewed as a whole, the results indicate that low electric
field enhanced cancer therapy can directly destroy the primary tumors, and
facilitates the destruction of residual metastatic disease, probably by eliciting an
anti-tumor immune/inflammatory response.
Thus, low electric field cancer therapy (LEFCT) with or without
chemotherapy is a promising treatment for solid tumors, instead of or
complementary to surgery, in the case of inoperable tumors or when organ
preservation is a major consideration.
... For direct administration into the tumour, the dose of injected drug is smaller than the normal intravenous dose unless the tumour volume is very large. As a result, if the tumour is very large or a large number of tumours are going to be electroporated, intravenous administration seems to be more convenient than intratumoural injection [14,83]. In previous studies, intravenous bleomycin was mostly given at a dose of 10 or 15 mg/m 2 (10-20 mg/m 2 of body surface), and when administered as an intratumoural injection, the dose was usually dependent on tumour volume and varied between 0.5 and 4 mg/cm 3 (of tumour size) [14]. ...
Electrochemotherapy is becoming a promising technique for the management of malignancies of skin and non-skin origin. The current review aims to clarify current knowledge on administration of elec-trochemotherapy for the treatment of various skin tumours. A systematic literature search was performed, up to the end of 2016, on studies in which the application of electrochemotherapy for management of primary and metastatic cutaneous malignant tumours was assessed. Having selected appropriate studies, pooled estimates of mean objective (com-plete) responses, with 95% confidence intervals (CIs), were calculated to assess treatment efficacy. Finally, the main emerging themes from the papers were discussed in more detail. From 465 records identified through database searching, a total of 128 studies were screened, of which 70 were included for review. After a pooled analysis, the estimate for mean objective response following electrochemotherapy was 84.02% (95% CI: 80.08-87.61). Furthermore, the pooled estimate of objective treatment response of evaluated studies was 83.91% (95% CI: 79.15-88.17%) for bleomycin and 80.82% (95% CI: 66.00-92.36%) for cisplatin. Electrochemotherapy is a feasible, inexpensive, fast and easy technique to perform local treatment, regardless of tumour type, with a low level of adverse effects and patient discomfort. This method can be applied alone for patients with primary cutaneous lesions, or local or locoregional metastases, or as an additional treatment modality in patients with distant metastases.
... Following this, a series of electrical pulses into the solid tumor are applied. This enhances the uptake of chemotherapeutic agents into cells and hence increases the cytotoxic effect to the cells (Mir et al., 1991;Jaroszeski et al., 2000;Mir, 2001). ...
Purpose:
Electrochemotherapy (ECT) is a therapeutic approach based on the local application of electrical pulses that permeabilize cell membranes to enhance the uptake of low-permeant chemotherapeutic agents, thus increasing their cytotoxic effects.
Materials and methods:
Twenty-one patients with SCC of the lower lip were treated according to the European Standard Operating Procedures of Electrochemotherapy. Bleomycin (15,000 IU/m2 body surface area) was administered intravenously over a 1-min period. Eight electrical pulses (amplitude, 1000 V/cm; duration, 100 μs) were generated and delivered at a repetition frequency of 5 kHz. Changes in tumor volume were used to assess treatment response.
Results:
Objective response (OR), complete response (CR), and partial response (PR) rates of 100%, 71.4%, and 28.6% respectively were demonstrated following a single session of ECT. ECT was well tolerated, and no adverse events occurred.
Conclusions:
Intravenous bleomycin-based ECT is a safe and effective therapy for SCC of the lower lip. ECT improves the quality-of-life of patients by preserving the function and the aesthetic appearance of the affected area. ECT provides a therapeutic option for elderly and frail patients who, due to their state of health, are not suitable for, or refuse surgical interventions.
... Electrochemotherapy, an emerging technique, for treating cancers involves applying high intensity, short duration pulses to enhance the drug uptake through the normally impermeable or less permeable cell membranes [1][2][3]. Electric field intensity and distribution is critical to open up pores and enhance the drug uptake. Typically, 4mm or 7 mm gap electrodes are used to treat the tumors [4][5][6]. ...
Presented in this paper is a useful model to evaluate the effect of tissue inhomogeneity in terms of electric field distribution when electroporation is applied to permeabilize cells for enhanced uptake of chemodrugs. The electric field is evaluated by means of Finite Element Analysis and is compared with the distribution found in a phantom model. The phantoms are built using potato that becomes dark if electroporated, and a Tissue-Mimic-Material, where the resistivity can be suitably designed. For this purpose, a pair of needles, with 2 cm gap was used to apply electric field. Both the numerical model and the phantom include a parallelepiped of homogeneous material with needles and a hole with diameter 7 mm, filled with materials with different resistivities. The hole in the middle, between the needles, simulates the inhomogeneity. This model can show the variation in the electric field when tissue inhomogeneities occur. The results illustrate the variations in the electric fields at different regions, which has promising clinical practice.
... Często spodziewane efekty uboczne cytostatyków są na tyle silne, że stanowią wyraźne przeciwskazanie do leczenia chorych w stadium uogólnionej choroby nowotworowej. Wśród metod dostarczenia cytostatyków badane są między innymi metody fi zyczne, w tym elektroporacja błon komórkowych [1]. ...
Modern trends in cancer treatment are focused on developing targeted therapies. Currently, studies based, both in creating nanoparticles which are ability to connect only to tumor cells and methods of their application. Electrochemotherapy (ECT) based on the phenomenon of reversible electroporation, i.e. a temporary increase in the cell membrane permeability due to the interaction of adequately modulated electric field. It is highly effective, especially in the palliative treatment of tumors located in skin and subcutaneous tissue. Recent publications give possibility either to use this method in such applications, as well as to work on its development. The future of electroporation is to use it for the treatment of non-resectable tumors of internal organs (liver, pancreas) as well as a method for gene transfer. (Farm Współ 2016; 9: 88-92)
... All rights reserved. [27] surface ECG electrodes and auricolar access for drug injections. B) Mediastinal access to left ventricle and placement of linear suction cup device (generous gift from Prof. Fred Wittkmapf, University Medical Center, Utrecht, Netherlands, and Dr. Kars Neven, Alfried Krupp Krankenhaus, Essen, Germany) on the pig epicardium. ...
Atrial fibrillation (AF) is one of the most important problems in modern cardiology. Thermal ablation therapies, especially radiofrequency ablation (RF), are currently “gold standard” to treat symptomatic AF by localized tissue necrosis. Despite the improvements in reestablishing sinus rhythm using available methods, both success rate and safety are limited by the thermal nature of procedures. Thus, while keeping the technique in clinical practice, safer and more versatile methods of removing abnormal tissue are being investigated. This review focuses on irreversible electroporation (IRE), a non-thermal ablation method, that is based on the unrecoverable permeabilization of cell membranes caused by short pulses of high voltage/current. While still in its preclinical steps for what concerns interventional cardiac electrophysiology, multiple studies have shown the efficacy of this method on animal models. The observed remodeling process shows this technique as tissue specific, triggering apoptosis rather than necrosis, and safer for the structures adjacent the myocardium. So far, proposed IRE methodologies are heterogeneous. The number of devices (both generators and applicators), techniques and therapeutic goals impair the comparability of performed studies. More questions regarding systemic safety and optimal processes for AF treatment remain to be answered.
... Furthermore, Köritzer et al. [8] investigated the anti-cancer properties of different dosages of CAP against TMZ-sensitive and TMZ-resistant cells and found that CAP treatment leads to a restored sensitivity of TMZ-resistant glioma cells to TMZ. ECT applies stronger electric fields to local tumor tissue after systemically or locally administered chemotherapy (bleomycin) [39], [40]. The triple combination with CAP (plasma-ECT) proved the most effective treatment with significant more survival days and less pronounced tumor growth by the CAP-bleomycin combination [4]. ...
Cold atmospheric plasma (CAP) interacting with tumor cells and finally leading to selective cell death has opened new horizons in cancer therapy. Despite significant progress in modern cancer treatment using immunologic and targeted therapies melanoma and glioblastoma presenting as brain metastases or primary tumor with poor prognosis are still a therapeutic challenge. The aim of the current study was to evaluate the potential of CAP (indirect treatment) in combination with the chemotherapeutics bleomycin, paclitaxel and dacarbazine to inhibit proliferation on human melanoma and glioblastoma cells in vitro. Cell lines of mouse melanoma (B16) were exposed for 1, 4, 12, 24 and 48 h, and of human melanoma (A375) and glioblastoma (A172) for 24 h to bleomycin, dacarbazine and paclitaxel together with plasma activated PBS. Directly after exposure cell proliferation after single (CAP, chemotherapeutic) or combined (CAP plus chemotherapeutic) treatment was assessed by cytotoxicity assay. Indirect CAP treatment of cell lines of glioblastoma and melanoma was followed by a strong reduction of proliferation most prominent after 24 h and 48 h exposure. With all drugs maximal reduction was achieved when drug-CAP combinations were used. Combination with CAP treating B16 melanoma cells reached 98% (48 h, combined with paclitaxel), A375 melanoma cells 82% (24 h, combined with bleomycin) and glioblastoma cells 96% (24 h, combined with paclitaxel). The combination of chemotherapy with CAP as indirect treatment may be beneficial in therapy of melanoma and glioblastoma by enhanced tumor reduction and less drug toxicity of chemotherapeutics.
... Despite the lack of precise understanding of the permeabilisation phenomenon, PEF treatment was already successfully implemented in various applied fields in both the medical area [28] and in the food industry [29][30][31][32]. It can be used to deliver non-permeant cytotoxic molecules for anti-cancerous treatment [33][34][35][36] or nucleic acids for simple transfection [37][38][39], for gene therapy and gene vaccines [39,40]. PEF treatment is also successful for extraction of compounds from various multicellular organisms such as grapes, sugar beets or other higher plants [29,32,41]. ...
Pulsed Electric Field (PEF) treatment was used as pre-treatment on the microalgae strain Auxenochlorella protothecoides (A.p.) prior to organic solvent extraction of lipids. Experiments were performed on fresh biomass from mixotrophic or autotrophic culture which both had an evaluated lipid content of 30–35% of cell dry weight. Lipid yield was determined gravimetrically and compared to the reference lipid content assessed by bead-milling and subsequent Soxhlet extraction. The biomass was concentrated at 10% w/w solids prior to PEF-treatment and further dewatered afterwards to approximately 25% w/w before extraction. PEF-treatment with an energy input of 1.5 MJ per kilogram of dry matter induced electropermeabilisation of the microalgae cells detected by the increase of the conductivity of the microalgae supernatant. This greatly increased the lipid yield upon subsequent monophasic solvent extraction. A mixture of Water/Ethanol/Hexane 1:18:7.3 vol/vol/vol enabled to recover 92%, and 72%, of the evaluated lipid content of mixotrophically, and autotrophically respectively, grown A.p., after 2 h of extraction. Recovery increased to 97%, and 90% respectively, after 20 h of extraction. The same extraction system on untreated biomass yielded maximum 10% of lipid content. The highest yields were obtained with 80 mL of solvent for 1 g dry biomass but solvent volume could be reduced by a factor two in case of mixotrophically grown microalgae. However, the solvent:biomass ratio still remains high, and includes a water-miscible solvent, ethanol. Total lipid extraction was confirmed by nile red staining of residual biomass combined with fluorescence microscopy imaging and flow cytometry. Gas chromatography analyses of extracted lipids after transesterification revealed that PEF- treatment did not alter their fatty acid composition. Overall PEF-treatment shows promising features for upscaling especially in a biorefinery concept since it avoids potentially harmful temperature increase and small debris problematic for further processing.
... We can use this ablation technique without triggering the entire body. The factors that affect the RE and IRE of the cells include electric field magnitude (voltage) and frequency as well as the period, duration, shape, and number of electric pulses [6]. The IRE pulses can be divided into two groups, including high-frequency/low-voltage and lowfrequency/high-voltage. ...
Introduction: Irreversible electroporation (IRE) is a process in which the membrane of the cancer cells are irreversibly damaged with the use of high-intensity electric pulses, which in turn leads to cell death. The IRE is a non-thermal way to ablate the cancer cells. This process relies on the distribution of the electric field, which affects the pulse amplitude, width, and electrical conductivity of the tissues. The present study aimed to investigate the relationship of the pulse width and intensity with the conductivity changes during the IRE using simulation.
Materials and Methods: For the purpose of the study, the COMSOL 5 software was utilized to predict the conductivity changes during the IRE. We used 4,000 bipolar and monopolar pulses with the frequency of 5 kHz and 1 Hz, width of 100 µs, and electric fields of low and high intensity. Subsequently, we built three-dimensional numerical models for the liver tissue.
Results: The results of our study revealed that the conductivity of tissue increased during the application of electrical pulses. Additionally, the conductivity changes increased with the elevation of the electric field intensity.
Conclusion: As the finding of this study indicated, the IRE with high-frequency and low electric field intensity could change the tissue conductivity. Therefore, the IRE was recommended to be applied with high frequency and low voltage.
... The combination of electroporation and chemotherapy is termed electrochemotherapy. By the use of electric fields, i.e. electroporation, the cell membrane is depolarized, making it permeable for molecules, which normally do not easily pass across the cell membrane [2][3][4][5]. Electroporation is used in vitro and in vivo in a number of settings, but clinically electrochemotherapy is mainly used in treatment of cutaneous and subcutaneous metastases [6]. ...
From the ICHNO congress in Barcelona March 2017
... Research on transportation of plasmid DNA through the plasma membrane under weak electric field entails complex phenomena with the cell membrane [11]. Recently, the electroporation laid foundation for the electrochemotherapy (ECT), improving the efficiency of cancer treatment [12,13]. Spectacular successes have been remarked especially in the therapy of melanoma. ...
Background: Recent developments in photomedicine and not promising prognosis of various types of cancer, have lead scientists to focus on PDT application in various types of cancer. This method offers an alternative treatment to conventional therapies, and it’s becoming increasingly accepted as a therapeutic modality in oncology. Additionally the combination of PDT with other anticancer treatment can enhance its efficiency.
Aim: The aim of our study was to examine the effect of PDT modified by 2-methoxyestradiol (2-Me) in human ovarian cells carcinoma (OvBH-1) with p53 overexpression and human breast adenocarcinoma cells (MCF-7). Additionally, there was evaluated the potential of electroporation (EP) in combination with photodynamic procedure.
Material and methods: Human ovarian clear carcinoma, breast carcinoma and melanoma cell line were used. Two photosensitizers were used: Photofrin and cyanine IR-786. The total light dose was 21.6 J/sq.cm obtained after 6 min of irradiation. The cells were treated with standard PDT, in combination with 2-Me or with electroporation. The dose of light was dependent on dye types. The photodynamic effect was examined by MTT and SRB assay. Apoptosis was estimated by TUNEL assay. The changes in cellular cytoskeleton were evaluated by CLSM method.
Results: The photocytotoxicity, apoptosis and changes in cytoskeleton were observed in ovarian and breast cells after PDT with 2-methoxyestradiol. The electroporation enhanced photodynamic reaction in all treated cells.
Conclusions: There was proved that the combination of PDT with 2-Me or EP allow for reduction of photosensitizers dose and can increase the effectiveness of the anticancer method.
... When a cell is exposed to an external electrical field for a short duration, transient thinning of the phospholipid bilayer with the formation of occurs nano-pores allowing passage of extracellular substances ( Figure 1). The 8 first practical demonstration of this phenomenon was the technique of DNA transfection of bacteria by applying a current from a laboratory generator. 9 The development and production of square wave generators, that allowed precision of treatment delivery in terms of the number of pulses and their characteristics facilitated electropermeabilization of a large population of cells without lethal cytotoxicity. ...
Background: Electrochemotherapy is a relatively new technique in the treatment of skin metastases that are not amenable to conventional therapy. Its use in breast cancer is now established in many European centers.
Methods: Published literature of electrochemotherapy in terms of its scientific basis, current clinical practice of breast cancer treatment providers, as well as the future directions for the technology has been reviewed.
Results: Collective global experience of the last 10 years has demonstrated Electrochemotherapy is a safe, well-tolerated and effective treatment of cutaneous breast cancer metastases and good outcome characteristics have been identified. However, successful treatment requires appropriate patient selection.
Conclusions: Electrochemotherapy is now established as a standard of care for cutaneous metastases. Its future use may extend to gene therapy and the treatment of visceral tumors.
... The application of electric pulses to the tumor tissue induces the formation of pores across the plasma membrane. The pores allow poorly permeant drugs to enter cells (Mir et al., 2001) enhancing in this way their efficacy. ...
Background:
The aim of this study was to investigate whether electrochemotherapy is a clinically and cost-effective treatment option against skin tumors.
Materials and methods:
We performed an analysis of the current literature based on database searches in PubMed/MEDLINE and we included articles till July 2012. Terms used for the search were 'electrochemotherapy', 'skin cancer', 'recurrence', and 'cutaneous and subcutaneous tumors'. Only papers published in English were included. In addition, we performed an analysis of the cost effectiveness of the method.
Results:
The combination of physics and chemistry is the foundation for electrochemotherapy and its efficacy, independent of the tumor histology. Clinical data showed that ECT is well tolerated and can be used in difficult cases without other available treatment options. The analysis also showed that the treatment is feasible and cost-effective.
Conclusions:
Electrochemotherapy is a clinically efficient, safe and cost-effective treatment and clinicians should not hesitate to use it as an alternative therapeutic modality or as palliative treatment.
... It involves the permeabilization of the cell membrane following the application of a short microsecond voltage, and facilitates targeted chemotherapy absorption, an approach that is referred to as electrochemotherapy (ECT). Bleomycin absorption can be enhanced up to 1000-fold [2], with a greatly reduced overall dosage required as a result. Clinical outcomes have been published for cutaneous disease in terms of tumor reduction, with an overall objective response rate of between 80 % and 90 % [3 -6] and associated quality of life improvement. ...
Background and study aims:
Targeted delivery of specific chemotherapeutic drugs into tumors can be achieved by delivering electrical pulses directly to the tumor tissue. This causes a transient formation of pores in the cell membrane that enables passive diffusion of normally impermeant drugs. A novel device has been developed to enable the endoscopic delivery of this tumor permeabilizing treatment. The aim of the preclinical studies described here was to investigate the efficacy and safety of this nonthermal ablation system in the treatment of gastrointestinal cancer models.
Methods:
Murine, porcine, and canine gastrointestinal tumors and tissues were used to assess the efficacy and safety of electroporation delivered through the special device in combination with bleomycin. Tumor cell death, volume, and overall survival were recorded.
Results:
Murine tumors treated with electrochemotherapy showed excellent responses, with cell death being induced rapidly, mainly via an apoptotic-type mechanism. Use of the system in canine gastrointestinal cancers demonstrated successful local endoluminal tumor resolution, with no safety or adverse effects noted.
Conclusions:
Electroporation via the new device in combination with bleomycin offers a nonthermal tumor ablative approach, and presents clinicians with a new option for the management of gastrointestinal cancers.
... Electroporation is typically performed by exposing cells to an electric field of sufficient strength to transiently permeabilize the cell membrane , then allowing it to reseal after the field is removed. Emerging applications of electroporation can be found in cancer treatment, gene therapy, transdermal drug delivery and stem cell research (Mir 2000; Gehl 2003). Electroporation has been commonly used on the macroscale to transfect millions of cells at once. ...
We present a hydrodynamically controlled, single-cell-rotation method to demonstrate electroporation-mediated molecular delivery in a microfluidic channel. Using a two-inlet geometry to control the carrier-flow profile, cell flow path and angular velocities can be controlled. When the flow-rate ratio between the fluid sheath and cell streams is balanced, fluidic shear occurs near the walls of the channel due to differential flow velocities between the streamlines. Single-cell angular velocities can then be explicitly controlled by using higher flow-rate ratios between the streams. Using sheathing streams with sufficiently high flow-rate ratios between the sheath and sample streams, cells are pinched against the sidewalls of the channel, which results in large degrees of cell rotation. We applied this technique to single-cell electroporation to increase the delivery of small molecules into the cell. Cell orientation was controlled along the length of the microchannel to continuously expose new cell membrane surface area to an applied electric field. Thus, the cell membrane becomes circumferentially permeabilized, resulting in a more efficient and uniform transport of micro- and macromolecules into rotating cells compared to the non-rotating one. Hydrodynamic control of cell rotation offers a new means to enhance intracellular delivery efficiency in single-cell electroporation.
... It uses electroporation, a physical drug delivery system, to deliver non-permeant or poorly permeant chemotherapeutic agents into the cells. 1 Among several clinically approved drugs that have been tested in preclinical studies, bleomycin and cisplatin have been demonstrated to be the most suitable drugs for clinical use of electrochemotherapy. [2][3][4][5] Exposure of cells to electric pulses increases cytotoxicity of bleomycin (8000 fold) and cisplatin (80 fold). 2,3 In vivo application of electric pulses to the tumours significantly potentiates antitumour effectiveness of bleomycin or cisplatin, given either intravenously 3,6 or intratumourally. ...
... If the TMP breaches a critical threshold, transient nanoscale pores form in the plasma membrane, which allow large molecules to traverse across the lipid bilayer 13 . This phenomenon, known as reversible electroporation 14 , is a well-established method used in aiding drug delivery, or for delivery of genetic material 15,16 . Beyond another critical TMP threshold, typically 1 V, irreparable damage occurs, preventing the resealing of these pores, which leads to cell death. ...
Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors.
... Unfortunately, this method induced type 2 immunity more than type 1, which is required against M. tuberculosis. Electrical pulse is another attempt to increase cell uptake for plasmid DNA (Mir, 2001). However, it is still unknown whether this method can actually increase immune protection. ...
During recent years, extensive development has been made to improving vaccines for tuberculosis.
This is due to the presence of genome sequences of diverse mycobacterial species and Mycobacteroum
tuberculosis (M. tb) isolates which has led to advances in the characterization of genes and antigens of M.
tb and better realization of protective immune responses to the disease in both animals and humans. This
review summarizes vaccine types, reasons for variable efficacy of BCG, latest advances in tuberculosis
vaccine development and major vaccine design strategies.
Keywords: Tuberculosis, vaccines, bacille Calmette-Guerin (BCG), Region of
... In this editorial, we highlight recent efforts to address some of the current challenges associated with treating deep-seated tumors using electroporation-based therapies, how several of the papers in this special issue address those challenges, and point readers to several excellent review articles in the field for further background information [2][3][4][5][6]. This special issue is a result of a special session, which was organized by COST TD1104 Action EP4Bio2Med (www.electroporation.net) at the MBEC2014 6 th European Conference of the International Federation for Medical and Biological Engineering held in Dubrovnik, Croatia from September 7-11, 2014. ...
... Les figures 2.8 et 2.9 montrent une hausse importante de la conductivité surfacique S m lorsque le voltage appliqué dépasse une valeur seuil. Cependant, du fait de la membrane épaissie, les intensités de leurs champs perméabilisants sont bien plus élevées que celles d'ordinaire rencontrées dans les expériences [54,55,39]. Les valeurs obtenues avec notre méthode de résolution sont plus proches de la réalité (figure 2.11). ...
Cell permeabilization by intense electric pulses, called electropermeabilization, is a biological phenomenon involved in recent anticancer therapies. It allows, for example, to increase the efficacy of chemotherapies still reducing their side effects, to improve gene transfer, or to proceed tumor ablation. However, mechanisms of electropermeabilization are not clearly explained yet, and the mostly adopted hypothesis of the formation of pores at the membrane surface is in contradiction with several experimental results.This thesis modeling work is based on a different approach than existing electroporation models. Instead of deriving equations on membranes properties from hypothesis at the molecular scale, we prefer to write ad hoc laws to describe them, based on available experimental data only. Moreover, to be as close as possible to these data, and to ease the forthcoming work of parameter calibration, we added to our model equations of transport and diffusion of molecules in the cell. Another important feature of our model is that we differentiate the conductive state of membranes from their permeable state.Numerical methods, as well as a 3D parallel C++ code were written and validated in order to solve the partial differential equations of our models. The modeling work was validated by showing qualitative match between our simulations and the behaviours that are observed in vitro
... Angiosarcomas are rare malignant tumors which arise from endothelial cells lining vascular channels. Breast angiosarcomas can be either observed as primary neoplasms or, more commonly, in upper limb lymphedema as a result of breast conservative surgery and radiotherapy for breast carcinoma [1][2][3][4][5][6][7][8][9][10] .Radiation-induced angiosarcoma (RIA) was first reported in the literature in 1929 11 , and is a common form of angiosarcoma. The diagnostic criteria for RIA include: a previous history of radiotherapy, peak incidence between 5 and 10 years, development of sarcoma within a previous irradiated field, histology confirmation .RIAs are characterized by their aggressive nature and most of them are high-grade tumors. ...
Angiosarcomas are highly malignant endothelial cell tumors with poor prognosis. These can be due to breast cancer itself or to subsequent therapeutic modalities. No evidence-based guidelines exist concerning the ideal treatment of angiosarcomas.
We report the case of a 76-year-old woman who developed an exuberant and aggressive post radiation angiosarcoma of the breast and discuss different aspects of therapy for this disease. A total left mastectomy was performed, followed by a right mastectomy. The lesions into the chest wall, and multiple abdominal skin nodules were treated with local Electrochemotherapy (ECT) with intravenous bleomicin.
No evidence-based guidelines exist concerning the ideal treatment of angiosarcomas. Electrochemotherapy (ECT) is an efficient palliative treatment of cutaneous and subcutaneous tumor nodules. It consists of the combination of a cytotoxic drug and electroporation, using appropriate electrical parameters; destabilization of the membrane is reversible, ensuring a high survival of permeabilized cells and the delivery of non-permeant molecules inside the cell.
Due to the rarity of the disease, prospective studies concerning adjuvant or neoadjuvant therapy are limited and no evidence-based guidelines exist. The response to chemotherapy seems to be poor. Treatment with ECT in addition to systemic chemotherapy achieves a complete response in all the lesions and improving patient body image perception.
Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
... The purpose of this note is to analyse an electroporation (Weaver and Chimadzhev 1996, Gaynor and Bodger 2006, Vernier et al 2006, Pliquett et al 2007, Chen et al 2008, Granot et al 2009, Levine and Vernier 2010method which avoids the need to insert electrodes into tumour regions, as is current practice in cancer treatment (Hoffmann et al 1999, Mir 2000, Gothelf et al 2003, Sersa et al 2008). The required high electric fields are provided by external electrodes, and amplified within the patient's body by elongated micro-conductors. ...
Electroporation in cancer therapy in which elongated micron-sized conductors are used to enhance an externally applied electric field is investigated. Such field enhancement was previously used in carbon and boron nitride nanotube electropermeabilization. It is envisaged that the micro-conductors would be injected together with therapeutic drugs into tumorous regions, and a pulsed or alternating external field would be applied. Amplification of this external electric field at the pointed ends of the elongated micro-conductors would then give (locally) a field sufficiently large to cause electroporation. The torque of the electric field on the polarized micro-conductors will tend to align them with the field, giving the configuration of maximum field enhancement at their ends. Brownian (thermal) motion will disrupt this alignment. We give an analysis of field enhancement, torque, and thermal motion for micro-conductors of prolate spheroidal shape, and estimate the range of their size for use in human tissue.
... It therefore allows electroporation of differentiated cells, which better resemble in-vivo cell phenotype. Is precisely in-vivo tissue electroporation, which is nowadays applied in the clinical treatment of different diseases (Mir 2001;Bodles-Brakhop et al. 2009;Matthiessen et al. 2011;, the perfect example when cells are not in suspension during the application of electric fields and supports the fact that electroporation of adherent cells describes a better model to study different aspects that could be translated in the improvement of the response to therapeutic treatments. Additionally, other factors involved in the efficiency of electroporation, such as surface-to-volume ratio and cytoskeleton, may differ in adherent and suspended cells. ...
In this study, a new microelectrode assembly based on spiral geometry applicable to in situ electroporation of adherent cell monolayers on standard multiwell plates is presented. Furthermore, the structure is specially conceived to perform electrical impedance spectroscopy (EIS) measurements during electroporation. Its performance for cell membrane permeabilization is tested with a fluorescent probe. Gene electrotransfer is also assayed using a plasmid DNA encoding GFP in four different cell lines (CHO, HEK293, 3T3-L1 and FTO2B). Additionally, siRNA α-GFP electrotransfection is tested in GFP gene-expressing CHO cells. Our data show considerable differences between permeabilization and gene transfer results and cell line dependence on gene expression rates. Successful siRNA electro-mediated delivery is also achieved. We demonstrate the applicability of our device for electroporation-mediated gene transfer of adherent cells in standard laboratory conditions. Finally, electrical impedance measurements during electroporation of CHO and 3T3-L1 cells are also given.
... If the cell cannot recover and it does not survive electroporation we call it irreversible [6]. Electroporation is widely used in different areas—gene transfer [7] [8] [9], cancer treatment [10] [11] [12], biotechnology [13] [14] and food processing [15] [16] [17]. ...
High voltage electric pulses cause electroporation of the cell membrane. Consequently, flow of the molecules across the membrane increases. In our study we investigated possibility to predict the percentage of the electroporated cells in inhomogeneous electric field on the basis of the experimental results obtained when cells were exposed to homogeneous electric field. We compared and evaluated different mathematical models previously suggested by other authors for interpolation of the results (symmetric sigmoid, asymmetric sigmoid, hyperbolic tangent and Gompertz curve). We investigated density of the cells and observed that it has the most significant effect on the electroporation of the cells while all four of the mathematical models yielded similar results. We were able to predict electroporation of cells exposed to inhomogeneous electric field based on mathematical modeling and using mathematical formulations of electroporation probability obtained experimentally using exposure to homogeneous field of the same density of cells. Models describing cell electroporation probability can be useful for development and presentation of treatment planning for electrochemotherapy and non-thermal irreversible electroporation.
... In medicine, electroporation is used with the method called electrochemotherapy in clinical practice for improved drug delivery for cancer treatment, and in preclinical (Serša et al. 1995;Serša et al. 1998;Serša et al. 2003;Heller et al. 1999;Mir and Orlowski 1999;Mir 2000). From the point of view of medical applications, it is more convenient to use a high-repetition pulse frequency rather than 1 Hz pulse repetition, which is currently used in clinical trials. ...
Background:
In recent years, superficial chest wall recurrence from breast cancer can be effectively treated by means of electrochemotherapy, with the majority of patients achieving response to treatment. Nevertheless, tumor spread along superficial lymphatic vessels makes this peculiar type of tumor recurrence prone to involve large skin areas and difficult to treat. In these cases, electroporation with standard, small size needle electrodes can be time-consuming and produce an inhomogeneous coverage of the target area, ultimately resulting in patient under treatment.
Materials and methods:
Authors designed and developed a prototype of a flexible grid electrode aimed at the treatment of large skin surfaces and manufactured a connection box to link the pulse applicator to a voltage pulse generator. Laboratory tests on potato tissue were performed in order to evaluate the electroporation effect, which was evaluated by observing color change of treated tissue.
Results:
A device has been designed in order to treat chest wall recurrences from breast cancer. According to preliminary tests, the new flexible support of the electrode allows the adaptability to the surface to be treated. Moreover, the designed devices can be useful to treat a larger surface in 2-5 minutes.
Conclusions:
Authors developed the prototype of a new pulse applicator aimed at the treatment of widespread superficial tumors. This flexible grid needle electrode was successfully tested on potato tissue and produced an electroporation effect. From a clinical point of view, the development of this device may shorten electrochemotherapy procedure thus allowing clinicians to administer electric pulses at the time of maximum tumor exposure to drugs. Moreover, since the treatment time is 2-5 min long, it could also reduce the time of anesthesia, thus improving patient recovery.
The impact of external medium conductivity on the efficiency of the reversible permeabilisation caused by pulsed electric fields was investigated. Pulses of 12 ns, 102 ns or 100 μs were investigated. Whenever permeabilisation could be detected after the delivery of one single pulse, media of lower conductivity induced more efficient reversible permeabilisation and thus independently of the medium composition. Effect of medium conductivity can however be hidden by some saturation effects, for example when pulses are cumulated (use of trains of 8 pulses) or when the detection method is not sensitive enough. This explains the contradicting results that can be found in the literature. The new data are complementary to those of one of our previous study in which an opposite effect of the conductivity was highlighted. It stresses that the conductivity of the medium influences the reversible permeabilization by several ways. Moreover, these results clearly indicate that electropermeabilisation does not linearly depend on the energy delivered to the cells.
Electrochemotherapy involves the application of chemotherapy followed by local electrical pulse around the tumor to increase drug delivery into tumor cells. Electroporation is used to increase drug absorbance only for medications whose transport is prevented by plasma membrane. Among all available medicines, bleomycin and cisplatin have been widely studied in pre-clinical and clinical trials. In-vitro observations revealed an increase in cytotoxicity of these drugs after the application of electrical pulses. In-vivo studies have suggested tumor electroporation after local or systemic chemotherapy therapy (electrochemotherapy) as an effective antitumor treatment. This method has also been successfully used in treating primary tumors of cats, dogs, and horses. Pre-clinical research on several types of tumor has clarified the parameters resulting to the effective, local control of tumors. In human clinical trials, electrochemotherapy has been an efficient method for treating advanced diseases with accessible malignant tumors of various types.
Electroporation - the use of electric pulses to increase cell membrane permeability - has also been used on skin for enhanced transdermal molecular delivery or to deliver molecules into viable skin cells. We theoretically described skin electropermeabilization and the amount of heating in and around an electrically created pore in the stratum corneum (SC), using finite element modeling. Theoretical results obtained with the model show no significant further thermal expansion of the aqueous pore for electrode design and pulse protocols we used for gene electrotransfer in vivo (already published results), as well as no thermal damage to the tissue. With some modifications to the protocol, electroporation could be used to a) create pores in the SC through which to transport the DNA, and then b) introduce the DNA into viable skin cells.
This paper presents a study about electrical resistance, which using fixed electrode geometry could be correlated to the tissue resistivity, of different histological types of human soft tissue sarcomas measured during electroporation. The same voltage pulse sequence was applied to the tumor mass shortly after surgical resection by means of a voltage pulse generator currently used in clinical practice for electrochemotherapy that uses reversible electroporation. The voltage pulses were applied by means of a standard hexagonal electrode composed by seven, 20-mm-long equispaced needles. Irrespective of tumor size, the electrode applies electric pulses to the same volume of tissue. The resistance value was computed from the voltage and current recorded by the pulse generator, and it was correlated with the histological characteristics of the tumor tissue which was assessed by a dedicated pathologist. Some differences in resistance values, which could be correlated to a difference in tissue resistivity, were noticed according to sarcoma histotype. Lipomatous tumors (i.e., those rich in adipose tissue) displayed the highest resistance values (up to 1700 Ω), whereas in the other soft tissue sarcomas, such as those originating from muscle, nerve sheath, or fibrous tissue, the electrical resistance measured was between 40 and 110 Ω. A variability in resistance was found also within the same histotype. Among lipomatous tumors, the presence of myxoid tissue between adipocytes reduced the electrical resistance (e.g., 50-100 Ω). This work represents the first step in order to explore the difference in tissue electrical properties of STS. These results may be used to verify whether tuning electric field intensity according to the specific STS histotype could improve tissue electroporation and ultimately treatment efficacy.
To achieve the maximal introduction of plasmid DNA into cells and, at the same time, to prevent undesirable cell deaths, electrotransfection conditions should be determined for every single cell type individually. In the present study, we determined the optimal electrotransfection parameters for in vitro transfection of B16F1, SA1, LPB, SCK, L929 and CHO cells. Some of these varying parameters were electric field strength, number of applied pulses and their duration, osmolarity of electroporation buffer, plasmid DNA concentration and temperature at which the electroporation was carried out. The maximal transfection rates at optimal electrotransfection parameters in B16F1, SA1, LPB, SCK, L929 and CHO were 85%, 40%, 60%, 1%, 40% and 65%, respectively. The obtained results confirmed that the electroporation is a useful procedure for an in vitro transfection of the majority of mammalian cells. The method, if optimized, may generate reproducibly high proportion of transfected cells among the cell types that are sensitive to electric field action. Thus, the determined parameters could serve for the subsequent implementations of this method.
The use of Irreversible Electroporation (IRE) for cancer treatment has increased sharply over the past decade. As a non-thermal therapy, IRE offers several potential benefits over other focal therapies which include: (1) short treatment delivery time, (2) reduced collateral thermal injury, and (3) the ability to treat tumors adjacent to major blood vessels. These advantages have stimulated widespread interest in basic through clinical studies of IRE. For instance, many in vitro and in vivo studies now identify treatment planning protocols (IRE threshold, pulse parameters, etc.), electrode delivery (electrode design, placement, intra-operative imaging methods, etc.), injury evaluation (methods and timing), and treatment efficacy in different cancer models. Therefore, this work reviews the in vitro, translational, and clinical studies of IRE cancer therapy based on major experimental studies particularly within the past decade. Further, this work provides organized data and facts to assist further research, optimization, and clinical applications of IRE.
Nonablative laser are one of the categories of devices in the field of nonablative methods. Sparing the
epidermis is the common mechanism of action of nonablative methods. The high complication rate of side
effects and the prolonged recovery time, encouraged the researchers to produce devices more safe than the
ancient ablative lasers.
Fibropapillomatosis continues to be an important cause of morbidity and mortality in sea turtles, particularly in Chelonia mydas. Turtles with this debilitating herpesvirus disease usually present with multiple, large, and ulcerated cutaneous masses that compromise both locomotion and feeding. There are very few available therapeutic strategies, with surgical excision being the most common. However, this surgical excision is associated with a high rate of local disease recurrence and secondary infections. Electrochemotherapy has been used for the treatment of epithelial neoplasm in several animal species. This technique is based on a combination of chemotherapy, usually with bleomycin or cisplatin, and electroporation. It consists of a series of short, high-voltage electric pulses that lead to increased membrane permeability and more efficient transport of antineoplastic drugs through the cellular membrane. Here, two C. mydas fibropapillomas were treated with a standard electrochemotherapy protocol using intralesional bleomycin sulfate injections followed by the application of electric pulses. Two sessions were performed, with a 33-day interval between sessions. Complete regression of lesions occurred without side effects or complications in each animal. There was no sign of local recurrence, even 1 yr after the end of treatment. Electrochemotherapy may be an effective therapeutic alternative for sea turtles with fibropapillomas.
Thirty years after the publication of the first report on gene electrotransfer in cultured cells by the delivery of delivering electric pulses, this technology is starting to be applied to humans. In 2008, at the time of the publication of the first edition of this book, reversible cell electroporation for gene transfer and gene therapy (nucleic acids electrotransfer) was at a cross roads in its development. In 5 years, basic and applied developments have brought gene electrotransfer into a new status. Present knowledge on the effects of cell exposure to appropriate electric field pulses, particularly at the level of the cell membrane, is reported here, as an introduction to the large range of applications described in this book. The importance of the models of electric field distribution in tissues and of the correct choice of electrodes and applied voltages is highlighted, as well as the large range of new specialized electrodes, developed also in the frame of the other electroporation-based treatments (electrochemotherapy). Indeed, electric pulses are now routinely applied for localized drug delivery in the treatment of solid tumors by electrochemotherapy. The mechanisms involved in DNA electrotransfer, which include cell electropermeabilization and DNA electrophoresis, are also surveyed: noticeably, the first molecular description of the crossing of a lipid membrane by a nucleic acid was reported in 2012. The progress in the understanding of cell electroporation as well as developments of technological aspects, in silico, in vitro and in vivo, have contributed to bring gene electrotransfer development to the clinical stage. However, spreading of the technology will require not only more clinical trials but also further homogenization of the protocols and the preparation and validation of Standard Operating Procedures.
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