Agent For Ablation Research Articles

Application Research of Bridge Plug Packer Rubber Tube Ablation Technology in Gas Storage

In the production process of oil and gas fields, for old wells, sealed wells, etc., if the bridge plug or packer is inserted into the well for a long time, the sealing cylinder will harden under the high-temperature and high-pressure environment of the wellbore. The sealing cylinder cannot contract normally and tightly adhere to the inner wall of the casing. During the tool unsealing and lifting process, impurities such as scale and rust on the casing wall will be scraped off and continuously accumulated, ultimately causing the bridge plug or packer to jam and unable to successfully complete the tool unsealing and salvage. During construction, the method of repeatedly moving the pipe column and suspending it is usually used for unblocking, and nitrogen gas lifting and lowering liquid construction is added, but the results are not ideal. During the process of moving the tubing, fatigue damage to the tubing increases the risk of well control and complex wellbore conditions, while significantly prolonging the construction period and increasing construction costs. Therefore, it is urgent to develop a degradation and ablation agent for hardened rubber parts, which can degrade and soften the hardened rubber cylinder, ensuring the smooth operation of tool salvage. Rubber products obtained through normal cross-linking reactions exhibit a regular grid like molecular structure, which can resist the invasion of organic molecules and oxidant molecules. This is also the reason why rubber products are resistant to organic solvents and acid-base corrosion. The experiment proposes to use a combination of "dissolution" and "destruction" methods to soften and melt the excessively cross-linked and hardened rubber cylinder.

Catheter‐Directed Ionic Liquid Embolic Agent for Rapid Portal Vein Embolization, Segmentectomy, and Bile Duct Ablation (Adv. Mater. 29/2024)

Catheter‐Directed Ionic Liquid Embolic Agent for Rapid Portal Vein Embolization, Segmentectomy, and Bile Duct Ablation (Adv. Mater. 29/2024)

Meperidine compared to morphine for rigors associated with monoclonal antibody-related infusion reactions.

Infusion reactions, characterized by symptoms such as rigors, fever, and hypotension, are common adverse events that occur during monoclonal antibody (MAB) therapy. The treatment of rigors often involves opioids, most commonly meperidine, despite limited evidence supporting use in the setting of MAB infusions. This study aims to compare the efficacy and safety of intravenous (IV) meperidine and morphine is treatment of MAB-related rigors, filling a significant gap in the literature. This was a single-center, retrospective cohort study which reviewed patients either inpatient or within outpatient infusion centers from January 2015 to January 2024. Patients receiving IV 2 mg morphine or 25 mg meperidine for MAB-related rigors were included. The primary outcome was defined as the number of opioid doses required for rigors ablation. Secondary outcomes included rates of naloxone administration and documented sedation. A total of 1251 administration events were screened, of which 127 and 26 rigor events were in the meperidine and morphine cohorts, respectively, were included. A majority of both cohorts required only one dose of either agent for rigors ablation with <20% of either cohort requiring 2 or more doses (p = 0.539). Low rates of sedation were observed in both groups. Both meperidine and morphine effectively manage MAB-related rigors within minimal safety concerns. These findings suggest that morphine is a suitable alternative to meperidine for this indication, which may influence future formulary decision, provide alternatives for drug shortage, and optimize supportive care for patients undergoing MAB therapy.

Remimazolam-flumazenil provides fast recovery from general anesthesia compared to propofol during radiofrequency catheter ablation of atrial fibrillation

The optimal anesthetic agent for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) and its impact on the recovery profiles remain uncertain. We compared the recovery and hemodynamic parameters between the remimazolam-flumazenil and propofol groups during RFCA. Patients were randomized into the remimazolam-flumazenil and propofol groups. The primary outcome measure was the time to eye opening following the discontinuation of anesthetic agents. Secondary outcomes included time to extubation, time to discharge from the operating room, intraprocedural hemodynamic variables and postoperative quality outcomes. Fifty-three patients were included in the final analysis (n = 26 in the remimazolam-flumazenil and n = 27 in the propofol group). The time to eye opening was significantly shorter in the remimazolam-flumazenil group compared to the propofol group (median [interquartile range]: 174 [157–216] vs. 353 [230–483] s, P < 0.001). The mean blood pressure and bispectral index were significantly higher in the remimazolam-flumazenil group compared to the propofol group (mean difference [95% CI], 7.2 [1.7–12.7] mmHg and 6 [3–8]; P = 0.011 and < 0.001, respectively), which were within target ranges in both groups. Other secondary outcomes were comparable between the groups. Consequently, remimazolam emerges as a promising anesthetic agent, characterized by rapid recovery and stable hemodynamics, during RFCA of AF.Trial registration: NCT05397886.

Catheter-Directed Ionic Liquid Embolic Agent for Rapid Portal Vein Embolization, Segmentectomy, and Bile Duct Ablation.

Embolic materials currently in use for portal vein embolization (PVE) do not treat the tumor, which poses a risk for tumor progression during the interval between PVE and surgical resection. Here, is developed an ionic-liquid-based embolic material (LEAD) for portal vein embolization, liver ablation, and drug delivery. LEAD is optimized and characterized for diffusivity, X-ray visibility, and cytotoxicity. In the porcine renal embolization model, LEAD delivered from the main renal artery reached vasculature down to 10 microns with uniform tissue ablation and delivery of small and large therapeutics. In non-survival and survival porcine experiments, successful PVE is achieved in minutes, leading to the expected chemical segmentectomy, and delivery of a large protein drug (i.e., Nivolumab) with LEAD. In cholangiocarcinoma mouse tumor models and in ex vivo human tumors, LEAD consistently achieved an effective ablation and wide drug distribution. Furthermore, various strains of drug-resistant patient-derived bacteria showed significant susceptibility to LEAD, suggesting that LEAD may also prevent infectious complications resulting from tissue ablation. With its capabilities to embolize, ablate, and deliver therapeutics, ease of use, and a high safety profile demonstrated in animal studies, LEAD offers a potential alternative to tumor ablation with or without PVE for FLR growth.

Minimally Invasive Delivery of Percutaneous Ablation Agent via Magnetic Colloidal Hydrogel Injection for Treatment of Hepatocellular Carcinoma.

Percutaneous thermotherapy, a minimally invasive operational procedure, is employed in the ablation of deep tumor lesions by means of target-delivering heat. Conventional thermal ablation methods, such as radiofrequency or microwave ablation, to a certain extent, are subjected to extended ablation time as well as biosafety risks of unwanted overheating. Given its effectiveness and safety, percutaneous thermotherapy gains a fresh perspective, thanks to magnetic hyperthermia. In this respect, an injectable- and magnetic-hydrogel-construct-based thermal ablation agent is likely to be a candidate for the aforementioned clinical translation. Adopting a simple and environment-friendly strategy, a magnetic colloidal hydrogel injection is introduced by a binary system comprising super-paramagnetic Fe3O4 nanoparticles and gelatin nanoparticles. The colloidal hydrogel constructs, unlike conventional bulk hydrogel, can be easily extruded through a percutaneous needle and then self-heal in a reversible manner owing to the unique electrostatic cross-linking. The introduction of magnetic building blocks is exhibited with a rapid magnetothermal response to an alternating magnetic field. Such hydrogel injection is capable of generating heat without limitation of deep penetration. The materials achieve outstanding therapeutic results in mouse and rabbit models. These findings constitute a new class of locoregional interventional thermal therapies with minimal collateral damages.

Exosome-Coated Prussian Blue Nanoparticles for Specific Targeting and Treatment of Glioblastoma.

Glioblastoma is one of the most aggressive and invasive types of brain cancer with a 5-year survival rate of 6.8%. With limited options, patients often have poor quality of life and are moved to palliative care after diagnosis. As a result, there is an extreme need for a novel theranostic method that allows for early diagnosis and noninvasive treatment as current peptide-based delivery standards may have off-target effects. Prussian Blue nanoparticles (PBNPs) have recently been investigated as photoacoustic imaging (PAI) and photothermal ablation agents. However, due to their inability to cross the blood-brain barrier (BBB), their use in glioblastoma treatment is limited. By utilizing a hybrid, biomimetic nanoparticle composed of a PBNP interior and a U-87 cancer cell-derived exosome coating (Exo:PB), we show tumor-specific targeting within the brain and selective thermal therapy potential due to the strong photoconversion abilities. Particle characterization was carried out and showed a complete coating around the PBNPs that contains exosome markers. In vitro cellular uptake patterns are similar to native U-87 exosomes and when exposed to an 808 nm laser, show localized cell death within the specified region. After intravenous injection of Exo:PB into subcutaneously implanted glioblastoma mice, they have shown effective targeting and eradication of tumor volume compared to PEG-coated PBNPs (PEG:PB). Through systemic administration of Exo:PB particles into orthotopic glioblastoma-bearing mice, the PBNP signal was detected in the brain tumor region through PAI. It was seen that Exo:PB had preferential tumor accumulation with less off-targeting compared to the RGD:PB control. Ex vivo analysis validated specific targeting with a direct overlay of Exo:PB with the tumor by both H&E staining and Ki67 labeling. Overall, we have developed a novel biomimetic material that can naturally cross the BBB and act as a theranostic agent for systemic targeting of glioblastoma tissue and photothermal therapeutic effect.

Development of peptides for targeting cell ablation agents concurrently to the Sertoli and Leydig cell populations of the testes: An approach to non-surgical sterilization.

The surgical sterilization of cats and dogs has been used to prevent their unwanted breeding for decades. However, this is an expensive and invasive procedure, and often impractical in wider contexts, for example the control of feral populations. A sterilization agent that could be administered in a single injection, would not only eliminate the risks imposed by surgery but also be a much more cost-effective solution to this worldwide problem. In this study, we sought to develop a targeting peptide that would selectively bind to Leydig cells of the testes. Subsequently, after covalently attaching a cell ablation agent, Auristatin, to this peptide we aimed to apply this conjugated product (LH2Auristatin) to adult male mice in vivo, both alone and together with a previously developed Sertoli cell targeting peptide (FSH2Menadione). The application of LH2Auristatin alone resulted in an increase in sperm DNA damage, reduced mean testes weights and mean seminiferous tubule size, along with extensive germ cell apoptosis and a reduction in litter sizes. Together with FSH2Menadione there was also an increase in embryo resorptions. These promising results were observed in around a third of all treated animals. Given this variability, we discuss how these reagents might be modified in order to increase target cell ablation and improve their efficacy as sterilization agents.

Carboxymethyl-sagocellulose-stabilized Fe3O4 nanoparticles with 5-fluorouracil as photothermal agents for tumor ablation

BackgroundThere is a continuous growth of interest in the development of nano-drug delivery systems that could combine therapy and diagnosis of cancer.ResultsNovel multifunctional superparamagnetic iron oxide nanoparticles (SPIONs, chemically Fe3O4) conjugated with carboxymethyl sagocellulose (CMSC), and 5-fluorouracil (Fe3O4-CMSC-5FU) were synthesized. The conjugated nanoparticles have the magnetic properties of the SPIONs, which allows the nanoparticles to be localized at the target area by applying an external magnetic field. SPIONs generate heat upon exposure to laser lights, resulting in a photothermic effect. The drug-loading efficiency of 5-FU into the SPIONs-CMSC conjugated nanoparticles was 70 to 84% w/w which could release the drug at intracellular pH (5.4) of cancer cells and resist drug release at pH 7.2. In vivo studies using mice models confirmed the nanoparticles could efficiently deliver 5-FU only to the cancer cells and the anticancer effect was enhanced by laser-induced hyperthermia.ConclusionsThe combination of targeted delivery of 5-FU with photothermal therapy (PTT) looks promising for selective killing of cancer cells. Furthermore, SPIONs are an excellent contrasting agent for use in computerized tomography (CT) imaging for determining the tumor location and monitoring the progress of the therapy. The focus of this work was the oncological application of multifunctional Fe3O4-CMSC-5FU nanoparticle conjugates, with an emphasis on therapeutic, diagnostic and prognostic purposes.

Liquid exfoliation of molybdenum metallenes for non-inflammatory photothermal therapy of tumors.

Tissue damage and cell death occurring during photothermal therapy (PTT) for tumors can induce an inflammatory response that is detrimental to tumor therapy. Herein, ultrathin Mo metallene nanosheets with a thickness of <5 nm prepared by liquid phase exfoliation were explored as functional hyperthermia agents for non-inflammatory ablation of tumors. The obtained Mo metallene nanosheets exhibited good photothermal conversion properties and significant reactive oxygen species (ROS) scavenging ability, thus achieving superior cancer cell ablation and anti-inflammatory effects in vitro. For in vivo experiments, 4T1 tumors were ablated while the inflammation-related cytokine levels did not obviously increase, demonstrating that the inflammatory response induced by PTT was inhibited by the anti-inflammatory properties of Mo metallene nanosheets. Moreover, Mo metallene nanosheets depicted good dispersibility and biocompatibility, beneficial for biomedical applications. This work introduces Mo metallenes as promising hyperthermia agents for non-inflammatory PTT of tumors.

Development of injectable colloidal solution forming an in situ hydrogel for tumor ablation.

Ablation cancer therapy using percutaneous intra-tumoral injection of ethanol is a promising method for targeted and effective locoregional cancer therapy. Magnetic gelatin microsphere (MGM) colloidal ethanol solution is developed as a potential injectable tumor ablation agent. The MGM was fabricated by electrostatic interactions among gelatin, acrylic acid, and acrylic acid-coated iron oxide nanoparticles. The fabricated MGM was dispersed in ethanol solution to form injectable MGM colloidal ethanol solution. The MGM colloidal ethanol solution can be easily infused and undergo in situ gelation via solvent exchange from ethanol to water in an artificial tissue. Furthermore, the MGM colloidal ethanol solution allowed doxorubicin (Dox) chemo-agent loading and its sustained release upon the formation of a drug depot by in situ gelation in artificial tissues. Our in vitro study demonstrated that locally delivered ethanol and Dox with MGM colloidal ethanol solution promoted the anti-cancer therapeutic efficacy with a significantly suppressed cancer cell recovery rate. Overall, our developed injectable MGM colloidal ethanol solution that can be transformed to a hydrogel drug depot at the injection site holds clinical potential for a new class of chemo-ablation agents.

Nuclear PARP1‐Targeted Photosensitizer as a Dual‐Mode DNA‐Damaging Agent and Immune Activator for Tumor Ablation (Adv. Healthcare Mater. 31/2023)

Nuclear PARP1‐Targeted Photosensitizer as a Dual‐Mode DNA‐Damaging Agent and Immune Activator for Tumor Ablation (Adv. Healthcare Mater. 31/2023)

Nuclear PARP1-Targeted Photosensitizer as a Dual-Mode DNA-Damaging Agent and Immune Activator for Tumor Ablation.

Photodynamic therapy is a promising cancer therapeutic method that can damage DNA via photoinduced reactive oxygen species production. However, tumor cells can initiate DNA repair pathways to resist oxidative damage. In this study, a nuclear-targeted photosensitizer PARP-PS with a poly (ADP-ribose) polymerase 1 (PARP1) inhibitory effect is developed based on the reported PARP1 inhibitor, rucaparib. As a dual-mode DNA-damaging agent, PARP-PS damages DNA upon photoirradiation and enhances oxidative DNA damage by blocking the DNA repair pathway via PARP1 inhibition and degradation. Both in vitro and in vivo investigations demonstrate that PARP-PS exhibits high antitumor activity with few side effects in breast cancer. In addition, PARP-PS can act as an immunogenic cell death inducer to activate immune responses characterized by the promotion of cytotoxic T lymphocyte activation and tumor infiltration. Therefore, PARP-PS is a potential multimodal antitumor agent with synergistic phototherapeutic, chemotherapeutic, and immunotherapeutic effects.

Ideal Anesthetic Agent for Cardiac Electrophysiology Study and Catheter Ablation – A Pilot Study

Objectives: Patients suffering from supraventricular tachycardia (SVT) require diagnostic or therapeutic intervention in a cardiac electrophysiology (EP) laboratory. Some anesthetic medications may adversely affect cardiac EP and conduction, altering the ability to induce the arrhythmia, and may have a negative impact on the ablation treatment. This prospective, randomized, pilot study was conducted in the cardiac EP laboratory of a tertiary care hospital with the aim to identify the ideal anesthetic agent for cardiac EP study and catheter ablation of SVT. The primary objective was to compare the effects of anesthetic agents on cardiac electrophysiological parameters and arrhythmia inducibility. The secondary objective was to compare the patient, anesthesiologist, and cardiologist satisfaction scores with respect to the anesthetic agent used. Materials and Methods: Thirty adult patients with SVT for EP study and radiofrequency catheter ablation were administered either of the anesthetic agents: midazolam, fentanyl, propofol, ketamine, or sevoflurane titrated to produce conscious sedation corresponding to bispectral index (BIS) values between 71 and 90. Electrophysiological parameters were recorded before and after administering the anesthetic agent. Results: Arrhythmia could be induced in all patients. Although electrophysiological parameters remained stable with ketamine administration; higher values of the Richmond Agitation Sedation Scale score and BIS were recorded. Propofol and sevoflurane administration was associated with deviation in electrophysiological parameters more than fentanyl and midazolam. The highest values of patient, anesthesiologist, and cardiologist satisfaction scores were obtained in the fentanyl group and the lowest in the ketamine group (P &lt; 0.002). Conclusion: In doses used to provide conscious sedation, fentanyl provided ideal conditions, and midazolam, propofol, sevoflurane, and ketamine provided satisfactory conditions for conducting EP study and catheter ablation for supraventricular tachyarrhythmias. The potential of propofol to impede cardiac conduction needs to be explored further.

Chlorin e6-modified iron oxide nanoparticles for photothermal-photodynamic ablation of glioblastoma cells.

Introduction: The effective treatment of glioblastoma still remains a great challenge. We herein report the development of chlorin e6 (Ce6)-conjugated iron oxide (Fe3O4-Ce6) nanoparticles for ablation of glioblastoma cells via combining photothermal therapy (PTT) with photodynamic therapy (PDT). Methods: Ce6 was conjugated to the synthesized Fe3O4 nanoparticles to form Fe3O4-Ce6 nanoparticles displaying the optical property of Ce6. Results and discussion: Under 808nm laser irradiation, Fe3O4-Ce6 nanoparticles generated heat and the temperature increase did not have obvious changes after five cycles of laser irradiation, suggesting their good photothermal effect and photothermal stability. In addition, 660nm laser irradiation of Fe3O4-Ce6 nanoparticles produced singlet oxygen (1O2) to mediate PDT. The Fe3O4-Ce6 nanoparticles without laser irradiation showed a low cytotoxicity, but they would obviously kill C6 cancer cells after laser irradiation via the combinational effect of PTT and PDT. Fe3O4-Ce6 nanoparticles thus could be used as a nanotherapeutic agent for combinational ablation of glioblastoma cells.

Side Chain Engineering of Amphiphilic Conjugated Polymer Nanoparticles for Biofilm Ablation

AbstractBiofilm recalcitrance, which enables bacteria to survive deep within the body under antimicrobial treatment, leading to persistent infections by reducing the penetration of antimicrobials, remains a major challenge in the antibacterial field. Conjugated polymer‐based nanoparticles with near‐infrared (NIR) photo responsiveness have emerged as a promising class of photothermal agents for biofilm ablation. However, the development of CPNs has been limited due to dissociation of the nanoparticles synthesized through nanoprecipitation. In this study, surface‐functionalized amphiphilic conjugated polymer‐based nanoparticles with photothermal conversion capacity for pH‐responsive targeting of bacteria are developed. The pH‐sensitive properties of the nanoparticles promote their adhesion to negatively charged bacterial surfaces, resulting in accumulation in biofilms. This accumulation enhances the ablation efficiency of biofilms under the synergistic photothermal effect. The method of constructing functional amphiphilic conjugated polymer‐based nanoparticles is simple to operate and can be used universally, providing a potential design option for biocompatible light‐responsive nanoparticles for in vivo applications.

Dual-Oxygenation/Dual-Fenton Synergistic Photothermal/Chemodynamic/Starvation Therapy for Tumor Treatment.

Due to the complexity of tumor pathogenesis and the heterogeneity of the tumor microenvironment (TME), it is difficult to obtain satisfactory efficacy with a single therapy. In this study, a hyaluronic acid (HA)-modified ruthenium nanoaggregate (RuNA) and glucose oxidase (GOD) -loaded manganese dioxide (MnO2) nanoflowers (MRG@HA) have been prepared. RuNA and MnO2 nanoflowers can generate O2 in TME, alleviating tumor tissue hypoxia. RuNA is a good photothermal agent for high-temperature ablation of solid tumors under infrared laser irradiation. GOD consumes glucose in the presence of O2 and converts it into glucuronic acid and hydrogen peroxide, reducing tumor nutrient supply while promoting Fenton-like reactions of MnO2 nanoflowers and RuNA to produce cytotoxic hydroxyl radicals. MRG@HA can also actively target tumor cells through the affinity of HA and CD44 receptor to improve the antitumor effect. In vitro and in vivo studies have confirmed the synergistic effect of MRG@HA with tumor photothermal/chemodynamic/starvation therapy, showing its great potential for clinical application in tumor therapy.

An Ionic Liquid Ablation Agent for Local Ablation and Immune Activation in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma rapidly acquires resistance to chemotherapy, remaining a fatal disease. Immunotherapy is one of the breakthroughs in cancer treatment, which includes immune checkpoint inhibitors, chimeric antigen receptor T-cell immunotherapy, and neoantigen vaccines. However, immunotherapy has not achieved satisfactory results in the treatment of pancreatic cancer. Immunogenic death comprises proinflammatory cell death, which provides a way to enhance tumor immunogenicity and promote an immune response in solid tumors. Herein, an ionic liquid ablation agent (LAA), synthesized from choline and geranic acid, which triggers necrosis-induced immunotherapy by remodeling an immunosuppressive "cold" tumor to an immune activated "hot" tumor is described. The results indicate that LAA-treated tumor cells can enhance immunogenicity, inducing dendritic cell maturation, macrophage M1 polarization, and cytotoxic T lymphocyte infiltration. The results of the present study provide a novel strategy for solid tumor immunotherapy.

Liquid exfoliation of stanene as degradable nanoagents for NIR-II photothermal therapy

Stanene, the two-dimensional form of elemental tin (Sn), is easily oxidized in the ambient environment, significantly hindering its applications in biomedical fields. However, the degradation mechanism of stanene remains unclear. Herein, combined DFT calculations and proof-of-concept experiments were conducted to elucidate the underlying degradation mechanism of stanene. The results reveal that the degradation of stanene in an oxygenated water environment is a water-accelerated oxidation process. H2O molecules could not only facilitate the electron transfer from stanene to O2 because of the polarization effect of H2O, but also directly react with the defect sites of stanene due to enhanced absorption energy. Moreover, several protective strategies like alcohol protection were proposed to avoid or mitigate the oxidation of stanene for further applications. Finally, stanene was explored as the second near-infrared (NIR-II) photonic agents for ablation of 4T1 tumor, depicting a tumor-growth inhibition ratio up to 96.7%, much better than that of the first near-infrared (NIR-I) group (65.5%). This work reveals the degradation mechanism of stanene and demonstrates its biomedical applications in the NIR-II region.

Diagnostic and therapeutic roles of iron oxide nanoparticles in biomedicine.

Nanotechnology changed our understanding of physics and chemics and influenced the biomedical field. Iron oxide nanoparticles (IONs) are one of the first emerging biomedical applications of nanotechnology. The IONs are composed of iron oxide core exhibiting magnetism and coated with biocompatible molecules. The small size, strong magnetism, and biocompatibility of IONs facilitate the application of IONs in the medical imaging field. We listed several clinical available IONs including Resovist (Bayer Schering Pharma, Berlin, Germany) and Feridex intravenous (I.V.)/Endorem as magnetic resonance (MR) contrast agents for liver tumor detection. We also illustrated GastroMARK as a gastrointestinal contrast agent for MR imaging. Recently, IONs named Feraheme for treating iron-deficiency anemia have been approved by the Food and Drug Administration. Moreover, tumor ablation by IONs named NanoTherm has also been discussed. In addition to the clinical application, several potential biomedical applications of IONs including cancer-targeting capability by conjugating IONs with cancer-specific ligands, cell trafficking tools, or tumor ablation agents have also been discussed. With the growing awareness of nanotechnology, further application of IONs is still on the horizon that would shed light on biomedicine.