Incorporation of Reversible Electroporation Into Electrolysis Accelerates Apoptosis for Rat Liver Tissue

Tissue electrolysis is an alternative modality that uses a low intensity direct electric current passing through at least 2 electrodes within the tissue and resulting electrochemical products including chlorine and hydrogen. These products induce changes in pH around electrodes and cause dehydration resulting from electroosmotic pressure, leading to changes in microenvironment and thus metabolism of the tissues, yielding apoptosis. The procedure requires adequate time for electrochemical reactions to yield products sufficient to induce apoptosis of the tissues. Incorporation of electroporation into electrolysis can decrease the treatment time and enhance the efficiency of electrolytic ablation. Electroporation causes permeabilization in the cell membrane allowing the efflux of potassium ions and extension of the electrochemical area, facilitating the electrolysis process. However, little is known about the combined effects on apoptosis in liver ablation. In this study, we performed an immunohistochemical evaluation of apoptosis for the incorporation of electroporation into electrolysis in liver tissues. To do so, the study was performed with microelectrodes for fixed treatment time while the applied voltage varied to increase the applied total energy for electrolysis. The apoptotic rate for electrolytic ablation increased with enhanced applied energy. The apoptotic rate was 4.31 ± 1.73 times that of control in the synergistic combination compared to 1.49 ± 0.33 times that of the control in electrolytic ablation alone. Additionally, tissue structure was better preserved in synergistic combination ablation compared to electrolysis with an increment of 3.8 mA. Thus, synergistic ablation may accelerate apoptosis and be a promising modality for the treatment of liver tumors.

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Single exponential decay waveform; a synergistic combination of electroporation and electrolysis (E2) for tissue ablation

10.7287/peerj.preprints.2549v1 ◽

2016 ◽

Author(s):

Nina Klein ◽

Enric Guenther ◽

Paul Mikus ◽

Michael K Stehling ◽

Boris Rubinsky

Keyword(s):

Electric Fields ◽

Exponential Decay ◽

Irreversible Electroporation ◽

Tissue Ablation ◽

Electrical Currents ◽

New Device ◽

Reversible Electroporation ◽

Electrolytic Ablation ◽

Synergistic Combination ◽

Single Exponential

Background: Electrolytic ablation and electroporation based ablation are minimally invasive, non-thermal surgical technologies that employ electrical currents and electric fields to ablate undesirable cells in a volume of tissue. In this study we explore the attributes of a new tissue ablation technology that simultaneously delivers a synergistic combination of electroporation and electrolysis (E2). Method: A new device that delivers a controlled dose of electroporation field and electrolysis currents in the form of a single exponential decay waveform (EDW), was applied to the pig liver and the effect of various parameters on the extent of tissue ablation was examined with histology. Results: Histological analysis shows that E2 delivered as EDW can produce tissue ablation in volumes of clinical significance, using electrical and temporal parameters which, if used in electroporation or electrolysis separately, cannot ablate the tissue Discussion: The E2 combination has advantages over the three basic technologies of non-thermal ablation: electrolytic ablation, electrochemical ablation (reversible electroporation with injection of drugs) and irreversible electroporation. E2 ablates clinically relevant volumes of tissue in a shorter period of time than electrolysis and electroporation, without the need to inject drugs as in reversible electroporation or use paralyzing anesthesia as in irreversible electroporation.

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Single exponential decay waveform; a synergistic combination of electroporation and electrolysis (E2) for tissue ablation

PeerJ ◽

10.7717/peerj.3190 ◽

2017 ◽

Vol 5 ◽

pp. e3190 ◽

Cited By ~ 8

Author(s):

Nina Klein ◽

Enric Guenther ◽

Paul Mikus ◽

Michael K. Stehling ◽

Boris Rubinsky

Keyword(s):

Electric Fields ◽

Exponential Decay ◽

Irreversible Electroporation ◽

Tissue Ablation ◽

Electrical Currents ◽

New Device ◽

Reversible Electroporation ◽

Electrolytic Ablation ◽

Synergistic Combination ◽

Single Exponential

Background Electrolytic ablation and electroporation based ablation are minimally invasive, non-thermal surgical technologies that employ electrical currents and electric fields to ablate undesirable cells in a volume of tissue. In this study, we explore the attributes of a new tissue ablation technology that simultaneously delivers a synergistic combination of electroporation and electrolysis (E2). Method A new device that delivers a controlled dose of electroporation field and electrolysis currents in the form of a single exponential decay waveform (EDW) was applied to the pig liver, and the effect of various parameters on the extent of tissue ablation was examined with histology. Results Histological analysis shows that E2 delivered as EDW can produce tissue ablation in volumes of clinical significance, using electrical and temporal parameters which, if used in electroporation or electrolysis separately, cannot ablate the tissue. Discussion The E2 combination has advantages over the three basic technologies of non-thermal ablation: electrolytic ablation, electrochemical ablation (reversible electroporation with injection of drugs) and irreversible electroporation. E2 ablates clinically relevant volumes of tissue in a shorter period of time than electrolysis and electroporation, without the need to inject drugs as in reversible electroporation or use paralyzing anesthesia as in irreversible electroporation.

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Single exponential decay waveform; a synergistic combination of electroporation and electrolysis (E2) for tissue ablation

10.7287/peerj.preprints.2549 ◽

2016 ◽

Author(s):

Nina Klein ◽

Enric Guenther ◽

Paul Mikus ◽

Michael K Stehling ◽

Boris Rubinsky

Keyword(s):

Electric Fields ◽

Exponential Decay ◽

Irreversible Electroporation ◽

Tissue Ablation ◽

Electrical Currents ◽

New Device ◽

Reversible Electroporation ◽

Electrolytic Ablation ◽

Synergistic Combination ◽

Single Exponential

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Obesity and orthodontic treatment: is there any direct relationship?

Dental Press Journal of Orthodontics ◽

10.1590/2177-6709.22.3.021-025.oin ◽

2017 ◽

Vol 22 (3) ◽

pp. 21-25 ◽

Cited By ~ 2

Author(s):

Alberto Consolaro

Keyword(s):

Tooth Movement ◽

Root Resorption ◽

Treatment Time ◽

Orthodontic Tooth Movement ◽

Normal Weight ◽

Scientific Data ◽

Specialized Training ◽

Wide Spread ◽

Obesity And Cancer ◽

Do So

ABSTRACT Obesity is a wide-spread condition directly or indirectly connected with an increase in the prevalence of a variety of human diseases. It affects over 50% of the western overall population. In 2017, a thorough analysis of 204 studies on obesity and cancer revealed that the condition increases the risk of the following types of cancer: stomach, colon, rectal, bile duct, pancreatic, esophagus, breast, endometrial, ovarian, kidney and multiple myeloma. The first study aiming at establishing a connection between obesity and the rate of induced orthodontic tooth movement was conducted by Saloom et al; however, it could not effectively nor significantly reveal any direct influence or effect. Despite being identified during the first week, differences could not be explained and treatment time remained unchanged. In spite of lack of studies in the literature on the connection between obesity and the rate of induced tooth movement, in clinical practice, courses or specialized training, we should not have protocols changed nor adopt any measures or expect significant differences between normal-weight and obese individuals. It should be emphasized that unsuccessful cases or cases of root resorption associated with treatment should not be assigned to obesity, since scientific data is insufficient to do so.

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Modeling of Inactivation of Biofilm Composing Bacteria with Low Intensity Electric Field: Prediction of Lowest Intensity and Mechanism

Pertanika Journal of Science and Technology ◽

10.47836/pjst.29.1.08 ◽

2021 ◽

Vol 29 (1) ◽

Author(s):

Mokhamad Tirono ◽

Suhariningsih

Keyword(s):

Electric Field ◽

Electric Fields ◽

Staphylococcus Epidermidis ◽

Treatment Time ◽

Irreversible Electroporation ◽

Pockels Effect ◽

Low Intensity ◽

Reversible Electroporation ◽

Effect Of Treatment ◽

Number Of Bacteria

Sterilization using high-intensity electric fields is detrimental to health if safety is inadequate, so it is necessary to study the possibility of sterilization using low-intensity electric fields. This study aims to determine the lowest electric field intensity and treatment time to deactivate the bacteria that make up the biofilms and explain the mechanism of inactivation. The study samples were biofilms from the bacteria Pseudomonas aeruginosa and Staphylococcus epidermidis grown on the catheter. The modeling formula was developed from the Pockels effect and the Weibull distribution with the treatment using a square pulse-shaped electric field with a pulse width of 50 μs and an intensity of 2.0-4.0 kV/ cm. The results showed that the threshold for irreversible electroporation of both samples occurred in the treatment using an electric field with an intensity of 3.5 kV/cm and 3.75 kV/ cm, respectively, where the size and type of Gram of bacteria influenced. Moreover, the time of the treatment had an effect when irreversible electroporation occurred. However, when there was reversible electroporation, the effect of treatment time on the reduction in the number of bacteria was not significant. Also, changes in conductivity affected the reduction in the number of bacteria when reversible electroporation occurred.

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Real-Time Impedance Monitoring During Electroporation Processes in Vegetal Tissue Using a High-Performance Generator

Sensors ◽

10.3390/s20113158 ◽

2020 ◽

Vol 20 (11) ◽

pp. 3158 ◽

Cited By ~ 1

Author(s):

Borja López-Alonso ◽

Héctor Sarnago ◽

Óscar Lucía ◽

Pablo Briz ◽

José Miguel Burdío

Keyword(s):

Real Time ◽

High Voltage ◽

High Performance ◽

Low Voltage ◽

Treatment Time ◽

Irreversible Electroporation ◽

The State ◽

Reversible Electroporation ◽

High Voltage Generator ◽

Vegetal Tissue

Classical application of electroporation is carried out by using fixed protocols that do not clearly assure the complete ablation of the desired tissue. Nowadays, new methods that pursue the control of the treatment by studying the change in impedance during the applied pulses as a function of the electric field are being developed. These types of control seek to carry out the treatment in the fastest way, decreasing undesired effects and treatment time while ensuring the proper tumour ablation. The objective of this research is to determine the state of the treatment by continuously monitoring the impedance by using a novel versatile high-voltage generator and sensor system. To study the impedance dynamics in real time, the use of pulses of reduced voltage, below the threshold of reversible electroporation, is tested to characterise the state-of-the-treatment without interfering with it. With this purpose, a generator that provides both low voltage for sense tissue changes and high voltage for irreversible electroporation (IRE) was developed. In conclusion, the characterisation of the effects of electroporation in vegetal tissue, combined with the real-time monitoring of the state-of-the-treatment, will enable the provision of safer and more effective treatments.

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Modulating electrolytic tissue ablation with reversible electroporation pulses

TECHNOLOGY ◽

10.1142/s233954781550003x ◽

2015 ◽

Vol 03 (01) ◽

pp. 45-53 ◽

Cited By ~ 25

Author(s):

Mary Phillips ◽

Narayan Raju ◽

Liel Rubinsky ◽

Boris Rubinsky

Keyword(s):

Cell Membrane ◽

Minimally Invasive ◽

Direct Current ◽

Tissue Damage ◽

Liver Tissue ◽

Tissue Ablation ◽

Target Region ◽

Reversible Electroporation ◽

Electrolytic Ablation

Electrolytic ablation is a minimally invasive tissue ablation technique that operates by delivering low magnitude direct current to the target region over long periods of time, generating electrolytic products that destroy cells. Our study seeks to examine the hypothesis that permeabilizing the cell membrane with reversible electroporation will reduce the electrolytic dose required for tissue ablation, by exposing the interior of the cell to the electrolytic products. The hypothesis is examined by evaluating the extent of tissue damage when electrolytic and reversible electroporation sequences are delivered separately and in combination, it in vivo, to rat liver tissue. The study shows that combining reversible electroporation with electrolysis produces a substantial increase in the extent of tissue ablation compared to that achieved by electrolysis alone.

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Efficient Use of Carbon Fibers as Heating Elements for Curing of Epoxy Matrix Composites

Molecules ◽

10.3390/molecules26165095 ◽

2021 ◽

Vol 26 (16) ◽

pp. 5095

Author(s):

Lykourgos C. Kontaxis ◽

Ioannis E. Chontzoglou ◽

George C. Papanicolaou

Keyword(s):

Electric Current ◽

Carbon Fibers ◽

Epoxy Resins ◽

Matrix Composites ◽

Financial Benefit ◽

Direct Electric Current ◽

Current Passing ◽

Three Point Bending ◽

Electric Current Passing ◽

Bending Mode

The aim of this study is to achieve a fully cured thermoset matrix that is heated by a direct electric current passing through the reinforcement fibers i.e., the Joule heating effect. Two types of fibers were used as heating elements for curing the epoxy resins. Kanthal resistance fibers were used as reference heating elements and subsequently, they were replaced by a Torayca Carbon Tow of the same radius. The specimens were cured by the heat produced by a direct electric current passing through the fibers and achieving temperatures of 50 °C and 70 °C. Specimens cured in a conventional oven were also manufactured, to compare the resistance heating method to the conventional one. Next, all specimens were mechanically characterized in a quasi-static three-point bending mode of loading and experimental results were compared to derive useful conclusions concerning the applicability of the technique to polymer/composite materials mass production. Finally, a preliminary economical study concerning power consumption needed for the application of both the traditional oven curing and the carbon fibers heating elements use for the manufacturing of the same amounts of materials is presented, showing a maximum financial benefit that can be achieved, on the order of 68%.

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Magnetic Resonance-Guided Stereotactic Body Radiotherapy of Liver Tumors: Initial Clinical Experience and Patient-Reported Outcomes

Frontiers in Oncology ◽

10.3389/fonc.2021.610637 ◽

2021 ◽

Vol 11 ◽

Author(s):

Fabian Weykamp ◽

Philipp Hoegen ◽

Sebastian Klüter ◽

C. Katharina Spindeldreier ◽

Laila König ◽

...

Keyword(s):

Magnetic Resonance ◽

Liver Metastases ◽

Local Control ◽

Treatment Time ◽

Liver Tumors ◽

University Hospital ◽

Treatment Quality ◽

Patient Acceptance ◽

Breath Hold ◽

Patient Reported

Purpose/ObjectiveStereotactic body radiation therapy (SBRT) has emerged as a valid treatment alternative for non-resectable liver metastases or hepatocellular carcinomas (HCC). Magnetic resonance (MR) guided SBRT has a high potential of further improving treatment quality, allowing for higher, tumoricidal irradiation doses whilst simultaneously sparing organs at risk. However, data on treatment outcome and patient acceptance is still limited.Material/MethodsWe performed a subgroup analysis of an ongoing prospective observational study comprising patients with liver metastases or HCC. Patients were treated with ablative MR-guided SBRT at the MRIdian Linac in the Department of Radiation Oncology at Heidelberg University Hospital between January 2019 and February 2020. Local control (LC) and overall survival (OS) analysis was performed using the Kaplan–Meier method. An in-house designed patient-reported outcome questionnaire was used to measure patients’ experience with the MR-Linac treatment. Toxicity was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE v. 5.0).ResultsTwenty patients (with n = 18 metastases; n = 2 HCC) received MR-guided SBRT for in total 26 malignant liver lesions. Median biologically effective dose (BED at α/β = 10) was 105.0 Gy (range: 67.2–112.5 Gy) and median planning target volume was 57.20 ml (range: 17.4–445.0 ml). Median treatment time was 39.0 min (range: 26.0–67.0 min). At 1-year, LC was 88.1% and OS was 84.0%. Grade I° gastrointestinal toxicity °occurred in 30.0% and grade II° in 5.0% of the patients with no grade III° or higher toxicity. Overall treatment experience was rated positively, with items scoring MR-Linac staff’s performance and items concerning the breath hold process being among the top positively rated elements. Worst scored items were treatment duration, positioning and low temperature.ConclusionMR-guided SBRT of liver tumors is a well-tolerated and well-accepted treatment modality. Initial results are promising with excellent local control and only mildest toxicity. However, prospective studies are warranted to truly assess the potential of MR-guided liver SBRT and to identify which patients profit most from this new versatile technology.

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Comparison of multileaf collimator and conventional circular collimator systems in Cyberknife stereotactic radiotherapy

Journal of Radiation Research ◽

10.1093/jrr/rrw130 ◽

2017 ◽

Vol 58 (5) ◽

pp. 693-700 ◽

Cited By ~ 9

Author(s):

Taro Murai ◽

Yukiko Hattori ◽

Chikao Sugie ◽

Hiromitsu Iwata ◽

Michio Iwabuchi ◽

...

Keyword(s):

Treatment Time ◽

Liver Tumors ◽

Organs At Risk ◽

Conformity Index ◽

Target Coverage ◽

Multileaf Collimator ◽

Dose Delivery ◽

Suitable Target ◽

The Brain ◽

Better Than

Abstract Multileaf collimator (MLC) technology has been newly introduced with the Cyberknife system. This study investigated the advantages of this system compared with the conventional circular collimator (CC) system. Dosimetric comparisons of MLC and CC plans were carried out. First, to investigate suitable target sizes for the MLC mode, MLC and CC plans were generated using computed tomography (CT) images from 5 patients for 1, 3, 5 and 7 cm diameter targets. Second, MLC and CC plans were compared in 10 patients, each with liver and prostate targets. For brain targets, doses to the brain could be spared in MLC plans better than in CC plans (P ≤ 0.02). The MLC mode also achieved more uniform dose delivery to the targets. The conformity index in MLC plans was stable, irrespective of the target size (P = 0.5). For patients with liver tumors, the MLC mode achieved higher target coverage than the CC mode (P = 0.04). For prostate tumors, doses to the rectum and the conformity index were lowered in MLC plans compared with in CC plans (P ≤ 0.04). In all target plans, treatment times in MLC plans were shorter than those in CC plans (P < 0.001). The newly introduced MLC technology can reduce treatment time and provide favorable or comparable dose distribution for 1–7 cm targets. In particular, the MLC mode has dosimetric advantage for targets near organs at risk. Therefore, the MLC mode is recommended as the first option in stereotactic body radiotherapy.

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