Search Results
Medical Gas Plasma Jet Technology Targets Murine Melanoma in an Immunogenic Fashion
Medical technologies from physics are imperative in the diagnosis and therapy of many types of diseases. In 2013, a novel cold physical plasma treatment concept was accredited for clinical therapy. This gas plasma jet technology generates large amounts of different reactive oxygen and nitrogen species (ROS). Using a melanoma model, gas plasma technology is tested as a novel anticancer agent. Plasma technology derived ROS diminish tumor growth in vitro and in vivo. Varying the feed gas mixture modifies the composition of ROS. Conditions rich in atomic oxygen correlate with killing activity and elevate intratumoral immune-infiltrates of CD8+ cytotoxic T-cells and dendritic cells. T-cells from secondary lymphoid organs of these mice stimulated with B16 melanoma cells ex vivo show higher activation levels as well. This correlates with immunogenic cancer cell death and higher calreticulin and heat-shock protein 90 expressions induced by gas plasma treatment in melanoma cells. To test the immunogenicity of gas plasma treated melanoma cells, 50% of mice vaccinated with these cells are protected from tumor growth compared to 1/6 and 5/6 mice negative control (mitomycin C) and positive control (mitoxantrone), respectively. Gas plasma jet technology is concluded to provide immunoprotection against malignant melanoma both in vitro and in vivo.
Activation of murine immune cells upon co-culture with plasma-treated B16F10 melanoma cells
Recent advances in melanoma therapy increased median survival in patients. However, death rates are still high, motivating the need of novel avenues in melanoma treatment. Cold physical plasma expels a cocktail of reactive species that have been suggested for cancer treatment. High species concentrations can be used to exploit apoptotic redox signaling pathways in tumor cells. Moreover, an immune-stimulatory role of plasma treatment, as well as plasma-killed tumor cells, was recently proposed, but studies using primary immune cells are scarce. To this end, we investigated the role of plasma-treated murine B16F10 melanoma cells in modulating murine immune cells' activation and marker profile. Melanoma cells exposed to plasma showed reduced metabolic and migratory activity, and an increased release of danger signals (ATP, CXCL1). This led to an altered cytokine profile with interleukin-1β (IL-1β) and CCL4 being significantly increased in plasma-treated mono- and co-cultures with immune cells. In T cells, plasma-treated melanoma cells induced extracellular signal-regulated Kinase (ERK) phosphorylation and increased CD28 expression, suggesting their activation. In monocytes, CD115 expression was elevated as a marker for activation. In summary, here we provide proof of concept that plasma-killed tumor cells are recognized immunologically, and that plasma exerts stimulating effects on immune cells alone. © 2019 by the authors.
Medical Gas Plasma Treatment in Head and Neck Cancer—Challenges and Opportunities
Despite progress in oncotherapy, cancer is still among the deadliest diseases in the Western world, emphasizing the demand for novel treatment avenues. Cold physical plasma has shown antitumor activity in experimental models of, e.g., glioblastoma, colorectal cancer, breast carcinoma, osteosarcoma, bladder cancer, and melanoma in vitro and in vivo. In addition, clinical case reports have demonstrated that physical plasma reduces the microbial contamination of severely infected tumor wounds and ulcerations, as is often seen with head and neck cancer patients. These antimicrobial and antitumor killing properties make physical plasma a promising tool for the treatment of head and neck cancer. Moreover, this type of cancer is easily accessible from the outside, facilitating the possibility of several rounds of topical gas plasma treatment of the same patient. Gas plasma treatment of head and neck cancer induces diverse effects via the deposition of a plethora of reactive oxygen and nitrogen species that mediate redox-biochemical processes, and ultimately, selective cancer cell death. The main advantage of medical gas plasma treatment in oncology is the lack of adverse events and significant side effects compared to other treatment modalities, such as surgical approaches, chemotherapeutics, and radiotherapy, making plasma treatment an attractive strategy for the adjuvant and palliative treatment of head and neck cancer. This review outlines the state of the art and progress in investigating physical plasma as a novel treatment modality in the therapy of head and neck squamous cell carcinoma.
Oxidatively Modified Proteins: Cause and Control of Diseases
Proteins succumb to numerous post-translational modifications (PTMs). These relate to enzymatic or non-enzymatic reactions taking place in either the intracellular or extracellular compartment. While intracellular oxidative changes are mainly due to redox stress, extracellular PTMs may be induced in an inflammatory micro milieu that is rich in reactive species. The increasing recognition of oxidative modifications as a causing agent or side-effect of pathophysiological states and diseases puts oxidative PTMS (oxPTMs) into the spotlight of inflammation research. Pathological hyper-modification of proteins can lead to accumulation, aggregation, cell stress, altered antigenic peptides, and damage-associated molecular pattern (DAMP)-like recognition by host immunity. Such processes are linked to cardiovascular disease and autoinflammation. At the same time, a detailed understanding of the mechanisms governing inflammatory responses to oxPTMs may capitalize on new therapeutic routes for enhancing adaptive immune responses as needed, for instance, in oncology. We here summarize some of the latest developments of oxPTMs in disease diagnosis and therapy. Potential target proteins and upcoming technologies, such as gas plasmas, are outlined for future research that may aid in identifying the molecular basis of immunogenic vs. tolerogenic oxPTMs.
Plasma-derived reactive species shape a differentiation profile in human monocytes
Background: Monocyte-derived macrophages are key regulators and producers of reactive oxygen and nitrogen species (ROS/RNS). Pre-clinical and clinical studies suggest that cold physical plasma may be beneficial in the treatment of inflammatory conditions via the release of ROS/RNS. However, it is unknown how plasma treatment affects monocytes and their differentiation profile. Methods: Naïve or phorbol-12-myristate-13-acetate (PMA)-pulsed THP-1 monocytes were exposed to cold physical plasma. The cells were analyzed regarding their metabolic activity as well as flow cytometry (analysis of viability, oxidation, surface marker expression and cytokine secretion) and high content imaging (quantitative analysis of morphology. Results: The plasma treatment affected THP-1 metabolisms, viability, and morphology. Furthermore, a significant modulation CD55, CD69, CD271 surface-expression and increase of inflammatory IL1β, IL6, IL8, and MCP1 secretion was observed upon plasma treatment. Distinct phenotypical changes in THP-1 cells arguing for a differentiation profile were validated in primary monocytes from donor blood. As a functional outcome, plasma-treated monocytes decreased the viability of co-cultured melanoma cells to a greater extent than their non-treated counterparts. Conclusions: Our results suggest plasma-derived ROS/RNS shaped a differentiation profile in human monocytes as evidenced by their increased inflammatory profile (surface marker and cytokines) as well as functional outcome (tumor toxicity). © 2019 by the authors.
Cold argon plasma as adjuvant tumour therapy on progressive head and neck cancer: A preclinical study
Investigating 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.
Characterization of antimicrobial effects of Plasma-Treated Water (PTW) produced by Microwave-Induced Plasma (MidiPLexc) on pseudomonas fluorescens biofilms
For the decontamination of surfaces in the food production industry, plasma-generated compounds such as plasma-treated water or plasma-processed air offer many promising possibilities for future applications. Therefore, the antimicrobial effect of water treated with microwave-induced plasma (MidiPLexc) on Pseudomonas fluorescens biofilms was investigated. A total of 10 mL deionized water was treated with the MidiPLexc plasma source for 100, 300 and 900 s (pretreatment time) and the bacterial biofilms were exposed to the plasma-treated water for 1, 3 and 5 min (post-treatment time). To investigate the influence of plasma-treated water on P. fluorescens biofilms, microbiological assays (colony-forming units, fluorescence and XTT assay) and imaging techniques (fluorescence microscopy, confocal laser scanning microscopy, and atomic force microscopy) were used. The colony-forming units showed a maximum reduction of 6 log10 by using 300 s pretreated plasma water for 5 min. Additionally, a maximum reduction of 81% for the viability of the cells and a 92% reduction in the metabolic activity of the cells were achieved by using 900 s pretreated plasma water for 5 min. The microscopic images showed evident microbial inactivation within the biofilm even at the shortest pretreatment (100 s) and post-treatment (1 min) times. Moreover, reduction of the biofilm thickness and increased cluster formation within the biofilm was detected. Morphologically, the fusion of cell walls into a uniform dense cell mass was detectable. The findings correlated with a decrease in the pH value of the plasma-treated water, which forms the basis for the chemically active components of plasma-treated water and its antimicrobial effects. These results provide valuable insights into the mechanisms of inactivation of biofilms by plasma-generated compounds such as plasma-treated water and thus allow for further parameter adjustment for applications in food industry. © 2020 by the authors.
Plasma‐treated flammulina velutipes‐derived extract showed anticancer potential in human breast cancer cells
Natural products with medicinal properties are among alternative therapies of interest due to their high body tolerance. We aimed to determine whether nonthermal gas plasma could enhance the medicinal value of Flammulina velutipes mushrooms. Generated gas plasma was characterized by its emission spectrum in ambient air, pH, temperature, and H2O2 and NOx concentrations after exposure for various periods. Phenolic and flavonoid contents in the extracts were measured using antioxidant assays and Fourier transform infrared and ultraviolet‐visible spectroscopy. We analyzed the effects of the plasma‐treated mushroom‐derived extracts against breast carcinoma using the MCF7 and MDA‐MB231 cell lines. The extracts significantly and concentration dependently inhibited the growth of breast cancer cells without inducing toxicity in normal MCF10A cells, and induced apoptosis via oxidative stress, evidenced by DNA damage (γ‐ H2AX foci formation), and increased the population of MCF7 breast cancer cells arrested in the G2/M phase of the cell cycle. The extracts also induced mitochondrion‐mediated apoptosis of MCF7 cells through cytochrome c release and caspase cleavage activity. The plasma improved the biological activity of mushrooms by increasing their phenolic compounds that prevented the growth of breast cancer cells in vitro. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
Differential Sensitivity of Two Leukemia Cell Lines towards Two Major Gas Plasma Products Hydrogen Peroxide and Hypochlorous Acid
Oxidative stress has major implications for health and disease. At the same time, the term collectively describes the reactions to different types of reactive oxygen species (ROS) and oxidants, including hydrogen peroxide (H2O2) and hypochlorous acid (HOCl). However, how both compare in terms of cytotoxicity and mechanism of action is less known. Using two leukemia cell lines, Jurkat and THP-1, as model systems at similar cell concentrations, we found an 8-fold greater sensitivity of the former over the latter for H2O2 exposure. Unexpectantly, this was not the case with HOCl exposure. Jurkat cells were 2-fold more resistant to HOCl-induced cytotoxicity than THP-1 cells. In each cell type, the relatively more toxic oxidant also induced activation of caspases 3 and 7 at earlier time points, as time-lapse fluorescence microscopy revealed. The effects observed did not markedly correlate with changes in intracellular GSH and GSSG levels. In addition, siRNA-mediated knockdown of the Nrf2 target HMOX-1 encoding for HO-1 protein and the growth and survival factor IL-8 revealed Jurkat cells to become more sensitive to HOCl, while HO-1 and IL-8 siRNA-mediated knockdown in THP-1 cells produced greater sensitivity towards H2O2. siRNA-mediated knockdown of catalase increased oxidant sensitivity only negligibly. Collectively, the data suggest striking HOCl-resistance of Jurkat and H2O2 resistance of THP-1 cells, showing similar protective roles of HO-1 and IL-8, while caspase activation kinetics differ.
Cold Atmospheric Pressure Plasma in Wound Healing and Cancer Treatment
Plasma medicine is gaining increasing attention and is moving from basic research into clinical practice. While areas of application are diverse, much research has been conducted assessing the use of cold atmospheric pressure plasma (CAP) in wound healing and cancer treatment—two applications with entirely different goals. In wound healing, a tissue-stimulating effect is intended, whereas cancer therapy aims at killing malignant cells. In this review, we provide an overview of the latest clinical and some preclinical research on the efficacy of CAP in wound healing and cancer therapy. Furthermore, we discuss the current understanding of molecular signaling mechanisms triggered by CAP that grant CAP its antiseptic and tissue regenerating or anti-proliferative and cell death-inducing properties. For the efficacy of CAP in wound healing, already substantial evidence from clinical studies is available, while evidence for therapeutic effects of CAP in oncology is mainly from in vitro and in vivo animal studies. Efforts to elucidate the mode of action of CAP suggest that different components, such as ultraviolet (UV) radiation, electromagnetic fields, and reactive species, may act synergistically, with reactive species being regarded as the major effector by modulating complex and concentration-dependent redox signaling pathways.