Filters

2020 - 20223

More filters

2021 - 20233
Reset filters

Settings

End date: 2024 × Start date: 2020 × DDC: 530 × Subject: cold physical plasma × WGL Institute: INP ×

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Radiation Driven Chemistry in Biomolecules—is (V)UV Involved in the Bioactivity of Argon Jet Plasmas?
    (Lausanne : Frontiers Media, 2021) Bruno, G.; Wenske, S.; Mahdikia, H.; Gerling, T.; von Woedtke, T.; Wende, K.
    Cold physical plasmas, especially noble gas driven plasma jets, emit considerable amounts of ultraviolet radiation (UV). Given that a noble gas channel is present, even the energetic vacuum UV can reach the treated target. The relevance of UV radiation for antimicrobial effects is generally accepted. It remains to be clarified if this radiation is relevant for other biomedical application of plasmas, e.g., in wound care or cancer remediation. In this work, the role of (vacuum) ultraviolet radiation generated by the argon plasma jet kINPen for cysteine modifications was investigated in aqueous solutions and porcine skin. To differentiate the effects of photons of different wavelength and complete plasma discharge, a micro chamber equipped with a MgF2, Suprasil, or Borosilicate glass window was used. In liquid phase, plasma-derived VUV radiation was effective and led to the formation of cysteine oxidation products and molecule breakdown products, yielding sulfite, sulfate, and hydrogen sulfide. At the boundary layer, the impact of VUV photons led to water molecule photolysis and formation of hydroxyl radicals and hydrogen peroxide. In addition, photolytic cleavage of the weak carbon-sulfur bond initiated the formation of sulfur oxy ions. In the intact skin model, protein thiol modification was rare even if a VUV transparent MgF2 window was used. Presumably, the plasma-derived VUV radiation played a limited role since reactions at the boundary layer are less frequent and the dense biomolecules layers block it effectively, inhibiting significant penetration. This result further emphasizes the safety of physical plasmas in biomedical applications.
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Plasma, cancer, immunity
    (Bristol : IOP Publ., 2022) Bekeschus, Sander; Clemen, Ramona
    Albeit heavily investigated for several decades already, the importance of the immune system in targeting cancer has received wide clinical attention only in recent years. This is partly because of long-standing rather traditional concepts on tumor biology on the one hand and the complexity of the immune system and its processes on the other. The viewpoint of evaluating existing and emerging approaches in oncology based on toxicity to tumors and the ability to engage antitumor-immunity is gaining ground across several disciplines. Along those lines, cold physical plasma was suggested as potential anticancer tool more than a decade ago, but solid evidence of the immune system playing a role in plasma cancer treatment only emerged in recent years. Moreover, plasma may support cancer immunotherapies in the future. Cancer immunotherapies are systemic treatments with biologicals that were reported to synergize with existing local physical modalities before, such as radiotherapy and photodynamic therapy. This review outlines key concepts in oncology, immunology, and tumor therapy, links them to plasma research, and discusses immuno-oncological consequences. Finally, promising future clinical applications are summarized. Synoptically, first scientific evidence supports an immuno-oncological dimension of plasma cancer treatment in selected instances, but robust clinical evidence is still lacking. More basic and clinical research is needed to determine the immuno-molecular mechanisms and detailed plasma application modalities to facilitate real patient benefit in the long term.