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Now showing 1 - 10 of 27
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    The kINPen—a review on physics and chemistry of the atmospheric pressure plasma jet and its applications
    (Bristol : IOP Publ., 2018-5-16) Reuter, Stephan; von Woedtke, Thomas; Weltmann, Klaus-Dieter
    The kINPen® plasma jet was developed from laboratory prototype to commercially available non-equilibrium cold plasma jet for various applications in materials research, surface treatment and medicine. It has proven to be a valuable plasma source for industry as well as research and commercial use in plasma medicine, leading to very successful therapeutic results and its certification as a medical device. This topical review presents the different kINPen plasma sources available. Diagnostic techniques applied to the kINPen are introduced. The review summarizes the extensive studies of the physics and plasma chemistry of the kINPen performed by research groups across the world, and closes with a brief overview of the main application fields.
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    Foundations of plasmas for medical applications
    (Bristol : IOP Publ., 2022) von Woedtke, T.; Laroussi, M.; Gherardi, M.
    Plasma medicine refers to the application of nonequilibrium plasmas at approximately body temperature, for therapeutic purposes. Nonequilibrium plasmas are weakly ionized gases which contain charged and neutral species and electric fields, and emit radiation, particularly in the visible and ultraviolet range. Medically-relevant cold atmospheric pressure plasma (CAP) sources and devices are usually dielectric barrier discharges and nonequilibrium atmospheric pressure plasma jets. Plasma diagnostic methods and modelling approaches are used to characterize the densities and fluxes of active plasma species and their interaction with surrounding matter. In addition to the direct application of plasma onto living tissue, the treatment of liquids like water or physiological saline by a CAP source is performed in order to study specific biological activities. A basic understanding of the interaction between plasma and liquids and bio-interfaces is essential to follow biological plasma effects. Charged species, metastable species, and other atomic and molecular reactive species first produced in the main plasma ignition are transported to the discharge afterglow to finally be exposed to the biological targets. Contact with these liquid-dominated bio-interfaces generates other secondary reactive oxygen and nitrogen species (ROS, RNS). Both ROS and RNS possess strong oxidative properties and can trigger redox-related signalling pathways in cells and tissue, leading to various impacts of therapeutic relevance. Dependent on the intensity of plasma exposure, redox balance in cells can be influenced in a way that oxidative eustress leads to stimulation of cellular processes or oxidative distress leads to cell death. Currently, clinical CAP application is realized mainly in wound healing. The use of plasma in cancer treatment (i.e. plasma oncology) is a currently emerging field of research. Future perspectives and challenges in plasma medicine are mainly directed towards the control and optimization of CAP devices, to broaden and establish its medical applications, and to open up new plasma-based therapies in medicine.
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    Biological Risk Assessment of Three Dental Composite Materials following Gas Plasma Exposure
    (Basel : MDPI, 2022) Bekeschus, Sander; Miebach, Lea; Pommerening, Jonas; Clemen, Ramona; Witzke, Katharina
    Gas plasma is an approved technology that generates a plethora of reactive oxygen species, which are actively applied for chronic wound healing. Its particular antimicrobial action has spurred interest in other medical fields, such as periodontitis in dentistry. Recent work has indicated the possibility of performing gas plasma-mediated biofilm removal on teeth. Teeth frequently contain restoration materials for filling cavities, e.g., resin-based composites. However, it is unknown if such materials are altered upon gas plasma exposure. To this end, we generated a new in-house workflow for three commonly used resin-based composites following gas plasma treatment and incubated the material with human HaCaT keratinocytes in vitro. Cytotoxicity was investigated by metabolic activity analysis, flow cytometry, and quantitative high-content fluorescence imaging. The inflammatory consequences were assessed using quantitative analysis of 13 different chemokines and cytokines in the culture supernatants. Hydrogen peroxide served as the control condition. A modest but significant cytotoxic effect was observed in the metabolic activity and viability after plasma treatment for all three composites. This was only partially treatment time-dependent and the composites alone affected the cells to some extent, as evident by differential secretion profiles of VEGF, for example. Gas plasma composite modification markedly elevated the secretion of IL6, IL8, IL18, and CCL2, with the latter showing the highest correlation with treatment time (Pearson’s r > 0.95). Cell culture media incubated with gas plasma-treated composite chips and added to cells thereafter could not replicate the effects, pointing to the potential that surface modifications elicited the findings. In conclusion, our data suggest that gas plasma treatment modifies composite material surfaces to a certain extent, leading to measurable but overall modest biological effects.
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    Plasma medical oncology: Immunological interpretation of head and neck squamous cell carcinoma
    (Hoboken, NJ : Wiley Interscience, 2020) Witzke, Katharina; Seebauer, Christian; Jesse, Katja; Kwiatek, Elisa; Berner, Julia; Semmler, Marie‐Luise; Boeckmann, Lars; Emmert, Steffen; Weltmann, Klaus‐Dieter; Metelmann, Hans‐Robert; Bekeschus, Sander
    The prognosis of patients suffering from advanced-stage head and neck squamous cell carcinoma (HNSCC) remains poor. Medical gas plasma therapy receives growing attention as a novel anticancer modality. Our recent prospective observational study on HNSCC patients suffering from contaminated tumor ulcerations without lasting remission after first-line anticancer therapy showed remarkable efficacy of gas plasma treatment, with the ulcerated tumor surface decreasing by up to 80%. However, tumor growth relapsed, and this biphasic response may be a consequence of immunological and molecular changes in the tumor microenvironment that could be caused by (a) immunosuppression, (b) tumor cell adaption, (c) loss of microbe-induced immunostimulation, and/or (d) stromal cell adaption. These considerations may be vital for the design of clinical plasma trials in the future.
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    Risk Evaluation of EMT and Inflammation in Metastatic Pancreatic Cancer Cells Following Plasma Treatment
    (Lausanne : Frontiers Media, 2020) Freund, Eric; Spadola, Chiara; Schmidt, Anke; Privat-Maldonado, Angela; Bogaerts, Annemie; Woedtke, Thomas von; Weltmann, Klaus-Dieter; Heidecke, Claus-Dieter; Partecke, Lars-Ivo; Käding, André; Bekeschus, Sander
    The requirements for new technologies to serve as anticancer agents go far beyond their toxicity potential. Novel applications also need to be safe on a molecular and patient level. In a broader sense, this also relates to cancer metastasis and inflammation. In a previous study, the toxicity of an atmospheric pressure argon plasma jet in four human pancreatic cancer cell lines was confirmed and plasma treatment did not promote metastasis in vitro and in ovo. Here, these results are extended by additional types of analysis and new models to validate and define on a molecular level the changes related to metastatic processes in pancreatic cancer cells following plasma treatment in vitro and in ovo. In solid tumors that were grown on the chorion-allantois membrane of fertilized chicken eggs (TUM-CAM), plasma treatment induced modest to profound apoptosis in the tissues. This, however, was not associated with a change in the expression levels of adhesion molecules, as shown using immunofluorescence of ultrathin tissue sections. Culturing of the cells detached from these solid tumors for 6d revealed a similar or smaller total growth area and expression of ZEB1, a transcription factor associated with cancer metastasis, in the plasma-treated pancreatic cancer tissues. Analysis of in vitro and in ovo supernatants of 13 different cytokines and chemokines revealed cell line-specific effects of the plasma treatment but a noticeable increase of, e.g., growth-promoting interleukin 10 was not observed. Moreover, markers of epithelial-to-mesenchymal transition (EMT), a metastasis-promoting cellular program, were investigated. Plasma-treated pancreatic cancer cells did not present an EMT-profile. Finally, a realistic 3D tumor spheroid co-culture model with pancreatic stellate cells was employed, and the invasive properties in a gel-like cellular matrix were investigated. Tumor outgrowth and spread was similar or decreased in the plasma conditions. Altogether, these results provide valuable insights into the effect of plasma treatment on metastasis-related properties of cancer cells and did not suggest EMT-promoting effects of this novel cancer therapy. © Copyright © 2020 Freund, Spadola, Schmidt, Privat-Maldonado, Bogaerts, von Woedtke, Weltmann, Heidecke, Partecke, Käding and Bekeschus.
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    Low-Dose Oxidant Toxicity and Oxidative Stress in Human Papillary Thyroid Carcinoma Cells K1
    (Basel : MDPI, 2022) Lens, Hannah Hamada Mendonça; Lopes, Natália Medeiros Dias; Pasqual-Melo, Gabriella; Marinello, Poliana Camila; Miebach, Lea; Cecchini, Rubens; Bekeschus, Sander; Cecchini, Alessandra Lourenço
    Medical gas plasmas are of emerging interest in pre-clinical oncological research. Similar to an array of first-line chemotherapeutics and physics-based therapies already approved for clinical application, plasmas target the tumor redox state by generating a variety of highly reactive species eligible for local tumor treatments. Considering internal tumors with limited accessibility, medical gas plasmas help to enrich liquids with stable, low-dose oxidants ideal for intratumoral injection and lavage. Pre-clinical investigation of such liquids in numerous tumor entities and models in vitro and in vivo provided evidence of their clinical relevance, broadening the range of patients that could benefit from medical gas plasma therapy in the future. Likewise, the application of such liquids might be promising for recurrent BRAF(V600E) papillary thyroid carcinomas, resistant to adjuvant administration of radioiodine. From a redox biology point of view, studying redox-based approaches in thyroid carcinomas is particularly interesting, as they evolve in a highly oxidative environment requiring the capability to cope with large amounts of ROS/RNS. Knowledge on their behavior under different redox conditions is scarce. The present study aimed to clarify resistance, proliferative activity, and the oxidative stress response of human papillary thyroid cancer cells K1 after exposure to plasma-oxidized DMEM (oxDMEM). Cellular responses were also evaluated when treated with different dosages of hydrogen peroxide and the RNS donor sodium nitroprusside (SNP). Our findings outline plasma-oxidized liquids as a promising approach targeting BRAF(V600E) papillary thyroid carcinomas and extend current knowledge on the susceptibility of cells to undergo ROS/RNS-induced cell death.
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    Pancreatic Cancer Cells Undergo Immunogenic Cell Death upon Exposure to Gas Plasma-Oxidized Ringers Lactate
    (Basel : MDPI, 2023) Miebach, Lea; Mohamed, Hager; Wende, Kristian; Miller, Vandana; Bekeschus, Sander
    Survival rates among patients with pancreatic cancer, the most lethal gastrointestinal cancer, have not improved compared to other malignancies. Early tumor dissemination and a supportive, cancer-promoting tumor microenvironment (TME) limit therapeutic options and consequently impede tumor remission, outlining an acute need for effective treatments. Gas plasma-oxidized liquid treatment showed promising preclinical results in other gastrointestinal and gynecological tumors by targeting the tumor redox state. Here, carrier solutions are enriched with reactive oxygen (ROS) and nitrogen (RNS) species that can cause oxidative distress in tumor cells, leading to a broad range of anti-tumor effects. Unfortunately, clinical relevance is often limited, as many studies have forgone the use of medical-grade solutions. This study investigated the efficacy of gas plasma-oxidized Ringer’s lactate (oxRilac), a physiological solution often used in clinical practice, on two pancreatic cancer cell lines to induce tumor toxicity and provoke immunogenicity. Tumor toxicity of the oxRilac solutions was further confirmed in three-dimensional tumor spheroids monitored over 72 h and in ovo using stereomicroscope imaging of excised GFP-expressing tumors. We demonstrated that cell death signaling was induced in a dose-dependent fashion in both cell lines and was paralleled by the increased surface expression of key markers of immunogenic cell death (ICD). Nuclear magnetic resonance (NMR) spectroscopy analysis suggested putative reaction pathways that may cause the non-ROS related effects. In summary, our study suggests gas plasma-deposited ROS in clinically relevant liquids as an additive option for treating pancreatic cancers via immune-stimulating and cytotoxic effects.
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    Gas plasma irradiation of breast cancers promotes immunogenicity, tumor reduction, and an abscopal effect in vivo
    (Abingdon : Taylor & Franics, 2021) Mahdikia, Hamed; Saadati, Fariba; Freund, Eric; Gaipl, Udo S.; Majidzadeh-A, Keivan; Shokri, Babak; Bekeschus, Sander
    While many new and emerging therapeutic concepts have appeared throughout the last decades, cancer still is fatal in many patients. At the same time, the importance of immunology in oncotherapy is increasingly recognized, not only since the advent of checkpoint therapy. Among the many types of tumors, also breast cancer has an immunological dimension that might be exploited best by increasing the immunogenicity of the tumors in the microenvironment. To this end, we tested a novel therapeutic concept, gas plasma irradiation, for its ability to promote the immunogenicity and increase the toxicity of breast cancer cells in vitro and in vivo. Mechanistically, this emerging medical technology is employing a plethora of reactive oxygen species being deposited on the target cells and tissues. Using 2D cultures and 3D tumor spheroids, we found gas plasma-irradiation to drive apoptosis and immunogenic cancer cell death (ICD) in vitro, as evidenced by an increased expression of calreticulin, heat-shock proteins 70 and 90, and MHC-I. In 4T1 breast cancer-bearing mice, the gas plasma irradiation markedly decreased tumor burden and increased survival. Interestingly, non-treated tumors injected in the opposite flank of mice exposed to our novel treatment also exhibited reduced growth, arguing for an abscopal effect. This was concomitant with an increase of apoptosis and tumor-infiltrating CD4+ and CD8+ T-cells as well as dendritic cells in the tissues. In summary, we found gas plasma-irradiated murine breast cancers to induce toxicity and augmented immunogenicity, leading to reduced tumor growth at a site remote to the treatment area.
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    Nitric oxide density distributions in the effluent of an RF argon APPJ: Effect of gas flow rate and substrate
    (Bristol : IOP, 2014) Iseni, S.; Zhang, S.; Van Gessel, A.F.H.; Hofmann, S.; Van Ham, B.T.J.; Reuter, S.; Weltmann, K.-D.; Bruggeman, P.J.
    The effluent of an RF argon atmospheric pressure plasma jet, the so-called kinpen, is investigated with focus on the nitric-oxide (NO) distribution for laminar and turbulent flow regimes. An additional dry air gas curtain is applied around the plasma effluent to prevent interaction with the ambient humid air. By means of laser-induced fluorescence (LIF) the absolute spatially resolved NO density is measured as well as the rotational temperature and the air concentration. While in the laminar case, the transport of NO is attributed to thermal diffusion; in the turbulent case, turbulent mixing is responsible for air diffusion. Additionally, measurements with a molecular beam mass-spectrometer (MBMS) absolutely calibrated for NO are performed and compared with the LIF measurements. Discrepancies are explained by the contribution of the NO2 and N2O to the MBMS NO signal. Finally, the effect of a conductive substrate in front of the plasma jet on the spatial distribution of NO and air diffusion is also investigated.
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    Influence of aerosol injection on the liquid chemistry induced by an RF argon plasma jet
    (Bristol : IOP Publ., 2021) Sremački, Ivana; Bruno, Giuliana; Jablonowski, Helena; Leys, Christophe; Nikiforov, Anton; Wende, Kristian
    A radio-frequency driven plasma jet in annular geometry coupled with an aerosol injection into the effluent is proposed for the controllable reactive oxygen species (ROS)/reactive nitrogen species (RNS) production and delivery on biological targets in the context of plasma medicine, e.g. wound care. The role of the aqueous aerosol in modulating the reactive species production is investigated by combining physical and chemical analytics. Optical emission spectroscopy, electron paramagnetic resonance spectroscopy, and a biochemical model based on cysteine as a tracer molecule have been applied, revealing that aerosol injection shifts the production of ROS from atomic and singlet oxygen toward hydroxyl radicals, which are generated in the droplets. Species generation occurred mainly at the droplets boundary layer during their transport through the effluent, leading to a limited cysteine turnover upon introduction into the aerosol solution. The subsequent delivery of unmodified cysteine molecules at a target suggested the application of the plasma source for the topical delivery of drugs, expanding the potential applicability and effectiveness. The presence of RNS was negligible regardless of aerosol injection and only traces of the downstream products nitrate and nitrate were detected. In summary, the aerosol injection into the effluent opens new avenues to control UV radiation and reactive species output for the biomedical applications of non-thermal plasma sources, reaching out toward the regulation, safety, and efficacy of targeted applications.