Electrochemical Ablation Research Articles

Percutaneous Electrochemical Debridement of the Plantaris Tendon.

Plantaris tendon disorders are a well-known source of midportion Achilles tendinopathy. Plantaris tendon thickening and fibrous tissue formation between the tendons are the histologic abnormalities that are typically observed. Surgical approaches (scraping of the Achilles medial and ventral paratendinous tissues and excision of the plantaris tendon) have already shown good clinical outcomes; despite this, the cost-benefit ratio of these interventions may be unfavorable, and their accessibility is limited. Percutaneous needle electrolysis is a minimally invasive ablative technique increasingly being considered for the treatment of tendinopathies and associated conditions. Herein we introduce a novel procedure to treat plantaris tendon-related midportion Achilles tendinopathy. The procedure starts with the ultrasound-guided insertion of an uncoated needle (diameter, 0.30-0.40 mm; length, 30 mm) between the plantaris and Achilles tendons. Subsequently, galvanic current (intensity, 2 mA) is locally transferred, which induces instant nonthermal electrochemical ablation of the intertendinous tissues in close proximity to the needle, finally debriding the plantaris tendon. To further promote its release, the second part of the procedure involves partial tenotomy of the lateral peripheral aspects of the plantaris tendon. Usually, the session does not exceed 30 min. Percutaneous needle electrolysis may be considered as a valid alternative to surgery. The outpatient procedure presented herein is, in fact, safe and quick to perform. In addition, long suspension of working or sporting activities after treatment is not required. Future investigations are needed to ascertain the short- and long-term therapeutic outcomes of plantaris tendon-related midportion Achilles tendinopathy treatment, in particular by comparing them with those obtained with other mini-invasive interventions.

Micro-Extinction Spectroscopy (MExS): a versatile optical characterization technique

Micro-Extinction Spectroscopy (MExS), a flexible, optical, and spatial-scanning hyperspectral technique, has been developed and is described with examples. Software and hardware capabilities are described in detail, including transmission, reflectance, and scattering measurements. Each capability is demonstrated through a case study of nanomaterial characterization, i.e., transmission of transition metal dichalcogenides revealing transition energy and efficiency, reflectance of transition metal dichalcogenides grown on nontransparent substrates identifying the presence of monolayer following electrochemical ablation, and scattering to study single plasmonic nanoparticles and obtain values for the refractive index sensitivity and sensing figure of merit of over a hundred single particles with various shapes and sizes. With the growing integration of nanotechnology in many areas, MExS can be a powerful tool to both characterize and test nanomaterials.

Abstract 195: Electrochemical treatment produces pH changes in the tumor microenvironment that are toxic to cancer cells

Abstract Background: Locoregional therapy is playing an increasingly central role in the management of hepatocellular carcinoma (HCC), where ablation is distinguished among these techniques by its capacity to effect cure. Electrochemical treatment (EChT), a technique that facilitates necrosis via the application of direct current at low voltages shows promise; however, widespread use has been limited as studies of the underlying biology and the mechanism of action have been limited. Methods: A novel assay for the study of EChT mechanism was designed, wherein HCC cells (2.5e5 cells/mL) were embedded in low-melting temperature agarose (1.5%). EChT was performed on these assays between nitinol cathodes (d = 0.5 mm) and platinum anodes (d = 0.5 mm) in a variety of geometries. Buffering capacity of the encapsulation assay was varied via the addition of HEPES buffer at final concentrations of 10mM, 50mM, or 200mM. Either during or immediately following EChT, the following measurements were recorded: cell viability, pH, ROS burden, transmembrane potential, and temperature. Results: Following EChT, acidic pH was appreciated surrounding the anodes and basic pH surrounding the cathodes in regions where cell death was observed by fluorescence microscopy. Upon increasing the buffering capacity of the assay, the total area of cell death decreased (p < 10-6). There was not sufficient heat generation nor transmembrane potential to account for the observed cell death. A pH-threshold was identified, where a pH > 10.8 or < 4.4 was found to cause cell necrosis in the three different buffer conditions studied. By varying the number of electrodes, their spacing, and length of ablation, it was possible to shape the zone of cell death observed to an arbitrary geometry. Conclusions: The mechanism of EChT-induced cancer cell death is through the spread of acidic and basic species generated by hydrolysis of water upon electron transfer at the electrodes. The diffusion of these species leads to cell death in a predictable, pH dependent manner. These results suggest that an electrochemical ablation device could treat complex HCC tumor geometries with appropriate electrode placement and charge delivery. Citation Format: Nicholas Perkons, Elliot Stein, Chike Nwaezeapu, Joseph Wildenberg, Daniel Ackerman, Gregory Nadolski, Stephen Hunt, Terence Gade. Electrochemical treatment produces pH changes in the tumor microenvironment that are toxic to cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 195.

(Invited) Anomalous Corrosion of Bulk 2D Materials Leading to Stable Monolayers

In this talk, I will elucidate on a recently discovered, unprecedented, substrate assisted, anomalous corrosion or self-limiting electrochemical ablation (EA) process that transforms bulk layers of various two- dimensional (2D) transition metal dichalcogenides (TMDCs) into their corresponding monolayers quickly and at room temperature when subjected to a high anodic potential. In particular I will explain what role does the substrate, pH, electrolyte solution, applied anodic potential, temperature and finally, in specific cases, self-assemble monolayers (SAMs) play in determining the corrosion rates for the bulk and monolayer which ultimately leads to successful conversion of multilayer TMDCs into their corresponding monolayer. I will also talk about thin film transistors (TFTs) based on these monolayers which demonstrate current ON-OFF ratios in excess of 107 along with ON currents in the range of ~100µA/µm which is on-par with any state-of-the-art TFT technology.

3:00 PM Abstract No. 342 Rapid coaxial probe electrochemical (CoPE) ablation device iteration using computer-aided design (CAD) and 3D printing

3:00 PM Abstract No. 342 Rapid coaxial probe electrochemical (CoPE) ablation device iteration using computer-aided design (CAD) and 3D printing

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

BackgroundElectrolytic 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).MethodA 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.ResultsHistological 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.DiscussionThe 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.

Preparation of carbon dots/TiO2 electrodes and their photoelectrochemical activities for water splitting

Carbon dots with various functional groups can be employed as the potential sensitizer. In this study, carbon dots are obtained by electrochemical ablation of graphite rods in alkaline electrolyte. The better preparation condition is the applied potential of 40 V and the ablation time of 5 h. TiO2 nanotube arrays and TiO2 nanoparticles photoelectrodes are sensitized by the as-prepared carbon dots through using impregnation method. Carbon dots/TiO2 nanotube arrays electrodes exhibit greater photoelectrochemical hydrogen production activities than carbon dots/TiO2 nanoparticles electrodes. It is because more carbon dots can be well combined with TiO2 nanotube arrays. Based on the IPCE values in visible light region, the role of carbon dots on TiO2 nanotube arrays electrode depends on the up-converted PL behaviors from their surface states and the alkaline electrolyte. The results provide insight into carbon dots that serve as sensitizer of TiO2 photoelectrode in water splitting system of alkaline solution.

Abstract No. 243 - Preliminary characterization of a novel coaxial electrochemical ablation device

Abstract No. 243 - Preliminary characterization of a novel coaxial electrochemical ablation device

A Self-Limiting Electro-Ablation Technique for the Top-Down Synthesis of Large-Area Monolayer Flakes of 2D Materials.

We report the discovery of an electrochemical process that converts two dimensional layered materials of arbitrary thicknesses into monolayers. The lateral dimensions of the monolayers obtained by the process within a few seconds time at room temperature were as large as 0.5 mm. The temporal and spatial dynamics of this physical phenomenon, studied on MoS2 flakes using ex-situ AFM imaging, Raman mapping, and photoluminescence measurements trace the origin of monolayer formation to a substrate-assisted self-limiting electrochemical ablation process. Electronic structure and atomistic calculations point to the interplay between three essential factors in the process: (1) strong covalent interaction of monolayer MoS2 with the substrate; (2) electric-field induced differences in Gibbs free energy of exfoliation; (3) dispersion of MoS2 in aqueous solution of hydrogen peroxide. This process was successful in obtaining monolayers of other 2D transition metal dichalcogenides, like WS2 and MoTe2 as well.

Treatment of proximal hamstring tendinopathy-related sciatic nerve entrapment: presentation of an ultrasound-guided "Intratissue Percutaneous Electrolysis" application.

Proximal Hamstring Tendinopathy-related Sciatic Nerve Entrapment (PHTrSNE) is a neuropathy caused by fibrosis interposed between the semimembranosus tendon and the sciatic nerve, at the level of the ischial tuberosity. Ultrasound-guided Intratissue Percutaneous Electrolysis (US-guided EPI) involves galvanic current transfer within the treatment target tissue (fibrosis) via a needle 0.30 to 0.33 mm in diameter. The galvanic current in a saline solution instantly develops the chemical process of electrolysis, which in turn induces electrochemical ablation of fibrosis. In this article, the interventional procedure is presented in detail, and both the strengths and limits of the technique are discussed. US-guided EPI eliminates the fibrotic accumulation that causes PHTrSNE, without the semimembranosus tendon or the sciatic nerve being directly involved during the procedure. The technique is however of limited use in cases of compression neuropathy. US-guided EPI is a technique that is quick to perform, minimally invasive and does not force the patient to suspend their activities (work or sports) to make the treatment effective. This, coupled to the fact that the technique is generally well-tolerated by patients, supports use of US-guided EPI in the treatment of PHTrSNE.

Magnetic Resonance–Monitored Coaxial Electrochemical Ablation—Preliminary Evaluation of Technical Feasibility

PurposeTo evaluate the technical feasibility of a coaxial electrode configuration to rapidly create a mechanically defined electrochemical ablation zone monitored by magnetic resonance (MR) imaging in real time. Materials and MethodsA direct current generator supplied the nitinol cathode cage and central platinum anode for coaxial electrochemical ablation. Safety and efficacy were evaluated by measuring local pH, temperature, and current scatter in saline solutions. Ablation zone diameters of 3–6 cm (n = 72) were created on ex vivo bovine liver and verified by gross pathology. Feasibility of MR monitoring was evaluated using 8 swine livers to create ablations of 3 cm (n = 12), 4 cm (n = 4), and 5 cm (n = 4) verified by histology. ResultsLocal pH was 3.2 at the anode and 13.8 at the cathode. Current scatter was negligible. Ablation progress increased relative to local ion concentration, and MR signal changes corresponded to histologic findings. In the ex vivo model, the times to achieve complete ablation were 15 minutes, 20 minutes, 35 minutes, and 40 minutes for diameters of 3 cm, 4 cm, 5 cm, and 6 cm, respectively. Ablation times for the in situ model were 15 minutes, 35 minutes, and 50 minutes for 3 cm, 4 cm, and 5 cm, respectively. ConclusionsThe coaxial configuration mechanically defined the electrochemical ablation zone with times similar to comparably sized thermal ablations. MR compatibility allowed for real-time monitoring of ablation progress.

3:39 PM, Abstract No. 147 - Size and shape adjustable coaxial electrochemical ablation - in vitro and ex vivo evaluation of a novel experimental technique

3:39 PM, Abstract No. 147 - Size and shape adjustable coaxial electrochemical ablation - in vitro and ex vivo evaluation of a novel experimental technique

Common Origin of Green Luminescence in Carbon Nanodots and Graphene Quantum Dots

Carbon nanodots (C-dots) synthesized by electrochemical ablation and small molecule carbonization, as well as graphene quantum dots (GQDs) fabricated by solvothermally cutting graphene oxide, are three kinds of typical green fluorescence carbon nanomaterials. Insight into the photoluminescence origin in these fluorescent carbon nanomaterials is one of the important matters of current debates. Here, a common origin of green luminescence in these C-dots and GQDs is unraveled by ultrafast spectroscopy. According to the change of surface functional groups during surface chemical reduction experiments, which are also accompanied by obvious emission-type transform, these common green luminescence emission centers that emerge in these C-dots and GQDs synthesized by bottom-up and top-down methods are unambiguously assigned to special edge states consisting of several carbon atoms on the edge of carbon backbone and functional groups with C═O (carbonyl and carboxyl groups). Our findings further suggest that the competition among various emission centers (bright edge states) and traps dominates the optical properties of these fluorescent carbon nanomaterials.

Carbon quantum dots with photo-generated proton property as efficient visible light controlled acid catalyst

Developing light-driven acid catalyst will be very meaningful for the controlled-acid catalytic processes towards a green chemical industry. Here, based on scanning electrochemical microscopy (SECM) and ΔpH testing, we demonstrate that the 5-10 nm carbon quantum dots (CQDs) synthesized by electrochemical ablation of graphite have strong light-induced proton properties under visible light in solution, which can be used as an acid catalyst. The 5-10 nm CQDs' catalytic activity is strongly dependent on the illumination intensity and the temperature of the reaction system. As an effective visible light driven and controlled acid-catalyst, 5-10 nm CQDs can catalyze a series of organic reactions (esterification, Beckmann rearrangement and aldol condensation) with high conversion (34.7-46.2%, respectively) in water solution under visible light, while the 1-4 nm CQDs and 10-2000 nm graphite do not have such excellent catalytic activity. The use of 5-10 nm CQDs as a light responsive and controllable photocatalyst is truly a novel application of carbon-based nanomaterials, which may significantly push research in the current catalytic industry, environmental pollution and energy issues.

Activation of local and systemic anti-tumor immune responses by ablation of solid tumors with intratumoral electrochemical or alpha radiation treatments.

Cancer, the most devastating chronic disease affecting humankind, is treated primarily by surgery, chemotherapy, and radiation therapy. Surgery and radiotherapy are mainly used for debulking the primary tumor, while chemotherapy is the most efficient anti-metastatic treatment. To control better metastatic cancer, the host immune system should be stimulated. Yet, successful specific stimulation of the immune system against tumors was seldom achieved even in antigenic tumors. Our working hypothesis is that aggressive in situ tumor ablation can release tumor antigens and danger signals, which will enhance anti-tumor T cell responses resulting in the destruction of residual malignant cells in primary tumors and distant metastases. We developed two efficient in situ ablation treatments for solid cancer, which can be used to destroy the primary tumors and stimulate anti-tumor immune responses. The first treatment, electrochemical ablation, is applied through intratumoral electrodes, which deliver unipolar-pulsed electric currents. The second treatment, diffusing alpha-emitters radiation therapy (DaRT), is based on intratumoral (224)Ra-loaded wire(s) that release by recoil its daughter atoms. These short-lived alpha-emitting atoms spread in the tumor and spray it with lethal alpha particles. It was confirmed that these treatments effectively destroy various malignant animal and human primary solid tumors. As a consequence of such tumor ablation, tumor-derived antigenic material was released and provoked systemic T cell-dependent anti-tumor immunological reactions. These reactions conferred protection against a secondary tumor challenge and destroyed remaining malignant cells in the primary tumor as well as in distant metastases. Such anti-tumor immune responses could be further amplified by the immune adjuvant, CpG. Electrochemical ablation or DaRT together with chemotherapy and immunostimulatory agents can serve as treatment protocols for solid metastatic tumors and can be applied instead of or in combination with surgery.

EFFECTIVENESS OF ULTRASOUND-GUIDED PERCUTANEOUS ELECTROLYSIS INTRATENDON (EPI) IN THE TREATMENT OF INSERTIONAL PATELLAR TENDINOPATHY IN SOCCER PLAYERS

IntroductionPatellar tendinopathy or ‘jumper's knee’ is considered more of a degenerative (tendinosis) than a non-inflammatory process (tendinitis). Recent histopathological studies have shown the absence of inflammatory cells in this type...

Graphitic carbon quantum dots as a fluorescent sensing platform for highly efficient detection of Fe3+ ions

Reported here is a green synthesis of graphitic carbon quantum dots (GCQDs) as a fluorescent sensing platform for the highly sensitive and selective detection of Fe3+ ions. Through the electrochemical ablation of graphite electrodes in ultrapure water, uniform GCQDs with graphitic crystallinity and oxygen containing groups on their surfaces have been successfully prepared. The absence of acid, alkali, salt and organic compounds in the starting materials effectively avoids complex purification procedures and environmental contamination, leading to a green and sustainable synthesis of GCQDs. The oxygen functional groups (e.g., hydroxyl, carboxyl) contribute to the water solubility and strong interaction with metal ions, which enable the GCQDs to serve as a fluorescent probe for the highly sensitive and selective detection of Fe3+ ions with a detection limit as low as 2 nM. The high sensitivity of our GCQDs could be attributed to the formation of complexes between Fe3+ ions and the phenolic hydroxyls of GCQDs. The fluorescence lifetime of GCQDs in the presence and absence of Fe3+ was tested by time-correlated single-photon counting (TCSPC), which confirmed a dynamic fluorescence quenching mechanism.

A Review on Less-common Nanostructures

Less-comon nanostructures (nanoforms) such as “nanodumbbells”, “nanorices”, “nanolines”, “nanotowers”, “nanoshuttles”, “nanobowlings”, “nanowheels”, “nanofans”, “nanopencils”, “nanotrees”, “nanoarrows”, “nanonails”, “nanobottles”, or “nanovolcanoes”, among many others, have been reviewed. A considerable part of these nanoforms corresponds to gold, zinc oxide, and several binary inorganic compounds that are widely used in electronics. Synthesis methods for obtaining less-common nanoforms include wet-chemistry and electrochemical techniques, laser ablation, ultrasonic treatment, electron and ion beam irradiation, arc discharge, lithography, CVD and related routes, among others.

SCHU-49: Electrochemical Ablation of the Prostate: A Feasibility Study for the Treatment of Prostate Cancer and Benign Prostatic Hyperplasia

SCHU-49: Electrochemical Ablation of the Prostate: A Feasibility Study for the Treatment of Prostate Cancer and Benign Prostatic Hyperplasia

Selective electrochemical tumour ablation (SECTA): treatment of multiple skin metastases compared with surgery

Selective electrochemical tumour ablation (SECTA): treatment of multiple skin metastases compared with surgery