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- ItemConcept for improved handling ensures effective contactless plasma treatment of patients with kINPen® MED(Basel : MDPI, 2020) Hahn, Veronika; Grollmisch, Daniel; Bendt, Hannes; Woedtke, Thomas von; Nestler, Bodo; Weltmann, Klaus-Dieter; Gerling, TorstenThe nursing of patients with wounds is an essential part of medical healthcare. In this context, cold atmospheric-pressure plasma sources can be applied for skin decontamination and stimulation of wound healing. One of these plasma devices is the commercially available kINPen® MED (neoplas tools GmbH), a cold atmospheric-pressure plasma jet which is approved as a medical device, class-IIa. For the plasma treatment, a sterile disposable spacer is recommended to ensure a constant and effective distance between plasma and skin. The disadvantage of this spacer is its form and size which means that the effective axis/area is not visible for the attending doctor or qualified personnel and consequently it is a more or less intuitive treatment. In addition, the suggested perpendicular treatment is not applicable for the attending specialist due to lack of space or patient/wound positioning. A concept of a sensory unit was developed to measure the treatment distance and to visualize the effective treatment area for different angles. To determine the effective area for the plasma treatment, some exemplary methods were performed. Thus, the antimicrobial (Staphylococcus aureus DSM799/ATCC6538) efficacy, reactive oxygen species (ROS) distribution and (vacuum) ultraviolet ((V)UV) irradiation were determined depending on the treatment angle. Finally, a simplified first approach to visualize the effective treatment area at an optimal distance was designed and constructed to train attending specialists for optimal wound area coverage. © 2020 by the authors.
- ItemPeroxynitrous Acid Generated In Situ from Acidified H2O2 and NaNO2. A Suitable Novel Antimicrobial Agent?(Basel : MDPI, 2021) Balazinski, Martina; Schmidt-Bleker, Ansgar; Winter, Jörn; Woedtke, Thomas vonPeroxynitrite (ONOO−) and peroxynitrous acid (ONOOH) are known as short acting reactive species with nitrating and oxidative properties, which are associated with their antimicrobial effect. However, to the best of our knowledge, ONOOH/ONOO- are not yet used as antimicro-bial actives in practical applications. The aim is to elucidate if ONOOH generated in situ from acidified hydrogen peroxide (H2O2 ) and sodium nitrite (NaNO2 ) may serve as an antimicrobial active in disinfectants. Therefore, the dose-response relationship and mutagenicity are investigated. Antimicrobial efficacy was investigated by suspension tests and mutagenicity by the Ames test. Tests were conducted with E. coli. For investigating the dose-response relationship, pH values and concentrations of H2O2 and NaNO2 were varied. The antimicrobial efficacy is correlated to the dose of ONOOH, which is determined by numerical computations. The relationship can be described by the efficacy parameter W, corresponding to the amount of educts consumed during exposure time. Sufficient inactivation was observed whenever W ≥ 1 mM, yielding a criterion for inactivation of E. coli by acidified H2O2 and NaNO2 . No mutagenicity of ONOOH was noticed. While further investigations are necessary, results indicate that safe and effective usage of ONOOH generated from acidified H2O2 and NaNO2 as a novel active in disinfectants is conceivable. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- ItemCold argon plasma as adjuvant tumour therapy on progressive head and neck cancer: A preclinical study(Basel : MDPI, 2019) Hasse, Sybille; Seebauer, Christian; Wende, Kristian; Schmidt, Anke; Metelmann, Hans-Robert; Woedtke, Thomas von; Bekeschus, SanderInvestigating cold argon plasma (CAP) for medical applications is a rapidly growing, innovative field of research. The controllable supply of reactive oxygen and nitrogen species through CAP has the potential for utilization in tumour treatment. Maxillofacial surgery is limited if tumours grow on vital structures such as the arteria carotis. Here CAP could be considered as an option for adjuvant intraoperative tumour therapy especially in the case of squamous cell carcinoma of the head and neck. Further preclinical research is necessary to investigate the efficacy of this technology for future clinical applications in cancer treatment. Initially, a variety of in vitro assays was performed on two cell lines that served as surrogate for the squamous cell carcinoma (SCC) and healthy tissue, respectively. Cell viability, motility and the activation of apoptosis in SCC cells (HNO97) was compared with those in normal HaCaT keratinocytes. In addition, induction of apoptosis in ex vivo CAP treated human tissue biopsies of patients with tumours of the head and neck was monitored and compared to healthy control tissue of the same patient. In response to CAP treatment, normal HaCaT keratinocytes differed significantly from their malignant counterpart HNO97 cells in cell motility only whereas cell viability remained similar. Moreover, CAP treatment of tumour tissue induced more apoptotic cells than in healthy tissue that was accompanied by elevated extracellular cytochrome c levels. This study promotes a future role of CAP as an adjuvant intraoperative tumour therapy option in the treatment of head and neck cancer. Moreover, patient-derived tissue explants complement in vitro examinations in a meaningful way to reflect an antitumoral role of CAP. © 2019 by the authors.