The Induction of Combined Hyperthermal Ablation Effect of Irreversible Electroporation with Polydopamine Nanoparticle-Coated Electrodes.

Irreversible electroporation (IRE) is a prominent non-thermal ablation method widely employed in clinical settings for the focal ablation therapy of solid tumors. Utilizing high-voltage, short-duration electric pulses, IRE induces perforation defects in the cell membrane, leading to apoptotic cell death. Despite the promise of irreversible electroporation (IRE) in clinical applications, it faces challenges concerning the coverage of target tissues for ablation, particularly when compared to other thermal ablation therapies such as radiofrequency ablation, microwave ablation, and cryoablation. This study aims to investigate the induced hyperthermal effect of IRE by applying a polydopamine nanoparticle (Dopa NP) coating on the electrode. We hypothesize that the induced hyperthermal effect enhances the therapeutic efficacy of IRE for cancer ablation. First, we observed the hyperthermal effect of IRE using Dopa NP-coated electrodes in hydrogel phantom models and then moved to in vivo models. In particular, in in vivo animal studies, the IRE treatment of rabbit hepatic lobes with Dopa NP-coated electrodes exhibited a two-fold higher increase in temperature (ΔT) compared to non-coated electrodes. Through a comprehensive analysis, we found that IRE treatment with Dopa NP-coated electrodes displayed the typical histological signatures of hyperthermal ablation, including the disruption of the hepatic cord and lobular structure, as well as the infiltration of erythrocytes. These findings unequivocally highlight the combined efficacy of IRE with Dopa NPs for electroporation and the hyperthermal ablation of target cancer tissues.

The therapeutic efficacy of silver loaded rhenium disulfide nanoparticles as a photothermal agent for cancer eradication.

Cancer is a life-threatening disease when it is diagnosed at a late stage or treatment procedures fail. Inhibiting cancer cells in the tumor environment is a significant challenge for anticancer therapy. The photothermal effects of nanomaterials are being studied as a new cancer treatment. In this work, rhenium disulfide (ReS2) nanosheets were made by liquid exfoliation with gum arabic (GA) and coated with silver nanoparticles (AgNPs) to produce reactive oxygen species that destroy cancer cells. The synthesized AgNP-GA-ReS2 NPs were characterized using UV, DLS, SEM, TEM, and photothermal studies. According to the DLS findings, the NPs were about 216 nm in size and had a zeta potential of 76 mV. The TEM and SEM analyses revealed that the GA-ReS2 formed single-layered nanosheets on which the AgNPs were distributed. The photothermal effects of the AgNP-GA-ReS2 NPs at 50 µg/mL were tested with an 808 nm laser at 1.2 W cm-2, and they reached 55.8 °C after 5 min of laser irradiation. MBA-MB-231 cells were used to test the cytotoxicity of the newly designed AgNP-GA-ReS2 NPs with and without laser irradiation for 5 min. At 50 µg/mL, the AgNP-GA-ReS2 showed cytotoxicity, which was confirmed with calcein and EtBr staining. The DCFH-DA and flow cytometry analyses demonstrated that AgNP-GA-ReS2 nanosheets under NIR irradiation generated ROS with high anticancer activity, in addition to the photothermal effects.

Influence of HCl Concentration on Corrosion Behavior between Au or Cu Bonding Wires and the Bond Pad for Semiconductor Packaging.

Wire bonding, one of the methods for electrically connecting a semiconductor chip with a substrate, involves attaching thin metal wires to pads. It is the oldest electrical connection method that exhibits high compatibility with other processes. The metal wires used for electrical connection in wire bonding are mainly made of Au, Cu, and Ag. After the wire bonding, molding is performed using the epoxy molding compound (EMC). However, EMC inevitably contains ions such as halogen elements. In addition, it absorbs moisture due to its hydrophilicity, creating a corrosive environment with electrolytes. In this study, we evaluated the influence of hydrochloric acid concentration on corrosion behavior between Au or Cu bonding wires and sputtered Al bond pads. The electrochemical factors such as corrosion potential difference (ΔE), galvanic corrosion current density (ig), and anodic and cathodic Tafel slopes were found to influence galvanic corrosion behavior. Galvanic corrosion tendency in first bond and second bond areas of PCB unit specimen was confirmed.

Assessment of Hepatic Lesions After non-Thermal Tumor Ablation by Irreversible Electroporation in a Pig Model.

Irreversible electroporation (IRE) is a non-thermal and minimal invasive modality to ablate pathologic lesions such as hepatic tumors. Histological analysis of the initial lesions after IRE can help predict ablation efficacy. We aimed to investigate the histological characteristics of early hepatic lesions after IRE application using animal models. IRE (1500 V/cm, a pulse length of 100 µs, 60 or 90 pulses) was applied to the liver of miniature pigs. H&E and TUNEL staining were performed and analyzed. Ablated zones of pig liver were discolored and separated from the normal zone after IRE. Histologic characteristics of ablation zones included preserved hepatic lobular architecture with a unique hexagonal-like structure. Apoptotic cells were detected, and sinusoidal dilatation and blood congestion were observed, but hepatic arteries and bile ducts were intact around the ablation zones. The early lesions obtained by delivering monophasic square wave pulses through needle electrodes reflected typical histological changes induced by IRE. Therefore, it was found that the histological assessment of the early hepatic lesion after IRE can be utilized to predict the IRE ablation effect.