Plasma Processes and Cancer - Special Topical Cluster of the 2nd IWPCT Meeting

(First paragraph) Although the emerging multidisciplinary field of plasma medicine has been around for nearly two decades important advances have already taken place that could one day revolutionize healthcare and the way various challenging diseases can be treated.1-3Amongst these advances the effects of low temperature plasma (LTP) on cancer cells in vitro and in vivo stand out.4-13Current cancer treatment modalities, such as chemotherapy and radiation therapy, have serious side effects and tend to lose their benefits to the patients after a while. Therefore, novel and improved therapies that can be used alone or in conjunction with other methods are always sought after by the medical community. LTP is proving to be one such possibility. Mounting experimental evidence is showing that LTP acts on cancer cells and tumors via the reactive oxygen species (ROS) and reactive nitrogen species (RNS) it produces. These chemically reactive species which include O, O2−, OH, H2O2, NO, NO2−, and NO3− exhibit strong oxidative properties and/or trigger signaling pathways in biological cells that could lead to cell death by necrosis or apoptosis. In addition, several investigators have reported that LTP targets cancer cells in a selective manner, mostly sparing their healthy counterparts. This is an important finding that can play a crucial role in the acceptance of plasma technology as a safe and hopefully successful cancer treatment modality

Development of a Mobile Sensory Device to Trace Treatment Conditions for Various Medical Plasma Source Devices

The emerging use of low-temperature plasma in medicine, especially in wound treatment, calls for a better way of documenting the treatment parameters. This paper describes the development of a mobile sensory device (referred to as MSD) that can be used during the treatment to ease the documentation of important parameters in a streamlined process. These parameters include the patient’s general information, plasma source device used in the treatment, plasma treatment time, ambient humidity and temperature. MSD was developed as a standalone Raspberry Pi-based version and attachable module version for laptops and tablets. Both versions feature a user-friendly GUI, temperature–humidity sensor, microphone, treatment report generation and export. For the logging of plasma treatment time, a sound-based plasma detection system was developed, initially for three medically certified plasma source devices: kINPen® MED, plasma care®, and PlasmaDerm® Flex. Experimental validation of the developed detection system shows accurate and reliable detection is achievable at 5 cm measurement distance in quiet and noisy environments for all devices. All in all, the developed tool is a first step to a more automated, integrated, and streamlined approach of plasma treatment documentation that can help prevent user variability

Non-thermal plasma activates human keratinocytes by stimulation of antioxidant and phase II pathways

Non-thermal atmospheric pressure plasma provides a novel therapeutic opportunity to control redox-based processes, e.g. wound healing, cancer, and inflammatory diseases. By spatial and time-resolved delivery of reactive oxygen and nitrogen species, it allows stimulation or inhibition of cellular processes in biological systems. Our data show that both gene and protein expression is highly affected by non-thermal plasma. Nuclear factor erythroid-related factor 2 (NRF2) and phase II enzyme pathway components were found to act as key controllers orchestrating the cellular response in keratinocytes. Additionally, glutathione metabolism, which is a marker for NRF2-related signaling events, was affected. Among the most robustly increased genes and proteins, heme oxygenase 1, NADPH-quinone oxidoreductase 1, and growth factors were found. The roles of NRF2 targets, investigated by siRNA silencing, revealed that NRF2 acts as an important switch for sensing oxidative stress events. Moreover, the influence of non-thermal plasma on the NRF2 pathway prepares cells against exogenic noxae and increases their resilience against oxidative species. Via paracrine mechanisms, distant cells benefit from cell-cell communication. The finding that non-thermal plasma triggers hormesis-like processes in keratinocytes facilitates the understanding of plasma-tissue interaction and its clinical application

Neutrophil extracellular trap formation is elicited in response to cold physical plasma

Cold physical plasma is an ionized gas with a multitude of components, including hydrogen peroxide and other reactive oxygen and nitrogen species. Recent studies suggest that exposure of wounds to cold plasma may accelerate healing. Upon wounding, neutrophils are the first line of defense against invading microorganisms but have also been identified to play a role in delayed healing. In this study, we examined how plasma treatment affects the functions of peripheral blood neutrophils. Plasma treatment induced oxidative stress, as assessed by the oxidation of intracellular fluorescent redox probes; reduced metabolic activity; but did not induce early apoptosis. Neutrophil oxidative burst was only modestly affected after plasma treatment, and the killing of Pseudomonas aeruginosa and Staphylococcus aureus was not significantly affected. Intriguingly, we found that plasma induced profound extracellular trap formation. This was inhibited by the presence of catalase during plasma treatment but was not replicated by adding an equivalent concentration of hydrogen peroxide. Plasma-induced neutrophil extracellular trap formation was not dependent on the activity of myeloperoxidase or NADPH oxidase 2 but seemed to involve short-lived molecules. The amount of DNA release and the time course after plasma treatment were similar to that with the common neutrophil extracellular trap inducer PMA. After neutrophil extracellular traps had formed, concentrations of IL-8 were also significantly increased in supernatants of plasma-treated neutrophils. Both neutrophil extracellular traps and IL-8 release may aid antimicrobial activity and spur inflammation at the wound site. Whether this aids or exacerbates wound healing needs to be tested

Detecting Bacteria on Wounds with Hyperspectral Imaging in Fluorescence Mode

Chronic non-healing wounds represent an increasing problem. In order to enable physicians and nurses to make evidence based decisions on wound treatment, the professional societies call for supporting tools to be offered to physicians. Oxygen supply, bacteria colonization and other parameters influence the healing process. So far, these parameters cannot be monitored in an objective and routinely manner. Existing methods like the microbiological analysis of wound swabs, mean a great deal of effort and partly a long delay. In this paper 42 fluorescence images from 42 patients with diabetic foot ulcer, recorded with a hyperspectral imaging system (TIVITA®), converted for fluorescence imaging, were analysed. Beside the fluorescence images, information about the bacterial colonization is available from microbiological analysis of wound swabs. After preprocessing, principal component analysis, PCA, is used for data analysis with a 405 nm excitation wavelength, the emission wavelength range 510 - 745 nm is used for analysis. After dividing the data into a training and a test dataset it could be shown, that bacteria are detectable in the wound area. A quantification in bacterial colonization counts (BCC) was not in the focus of the research in this study stage

Non-thermal plasma treatment induces MAPK signaling in human monocytes

The application of non-thermal atmospheric pressure plasma raises a hope for the new wound healing strategies. Next to its antibacterial effect it is known to stimulate skin cells. However, monocytes are also needed for the complex process of a wound healing. This study investigates the impact of plasma on the intracellular signaling events in the primary human monocytes. The proliferative MEK-ERK (MAPK/ERK kinase-extracellular signal-regulated kinase) pathway was activated by short plasma treatment times. In contrast, an induction of the apoptotic JNK (c-Jun N-terminal kinase) cascade as well as activation of caspase 3 were observed after long plasma exposure. These findings indicate that monocytes can be differentially stimulated by plasma treatment and may contribute to the proper wound recovery

Redox Stimulation of Human THP-1 Monocytes in Response to Cold Physical Plasma

In plasma medicine, cold physical plasma delivers a delicate mixture of reactive components to cells and tissues. Recent studies suggested a beneficial role of cold plasma in wound healing. Yet, the biological processes related to the redox modulation via plasma are not fully understood. We here used the monocytic cell line THP-1 as a model to test their response to cold plasma in vitro. Intriguingly, short term plasma treatment stimulated cell growth. Longer exposure only modestly compromised cell viability but apparently supported the growth of cells that were enlarged in size and that showed enhanced metabolic activity. A significantly increased mitochondrial content in plasma treated cells supported this notion. On THP-1 cell proteome level, we identified an increase of protein translation with key regulatory proteins being involved in redox regulation (hypoxia inducible factor 2α), differentiation (retinoic acid signaling and interferon inducible factors), and cell growth (Yin Yang 1). Regulation of inflammation is a key element in many chronic diseases, and we found a significantly increased expression of the anti-inflammatory heme oxygenase 1 (HMOX1) and of the neutrophil attractant chemokine interleukin-8 (IL-8). Together, these results foster the view that cold physical plasma modulates the redox balance and inflammatory processes in wound related cells

A New CYP2E1 Inhibitor, 12-Imidazolyl-1-dodecanol, Represents a Potential Treatment for Hepatocellular Carcinoma

Cytochrome P450 2E1 (CYP2E1) is a key target protein in the development of alcoholic and nonalcoholic fatty liver disease (FLD). The pathophysiological correlate is the massive production of reactive oxygen species. The role of CYP2E1 in the development of hepatocellular carcinoma (HCC), the final complication of FLD, remains controversial. Specifically, CYP2E1 has not yet been defined as a molecular target for HCC therapy. In addition, a CYP2E1-specific drug has not been developed. We have already shown that our newly developed CYP2E1 inhibitor 12-imidazolyl-1-dodecanol (I-ol) was therapeutically effective against alcoholic and nonalcoholic steatohepatitis. In this study, we investigated the effect of I-ol on HCC tumorigenesis and whether I-ol could serve as a possible treatment option for terminal-stage FLD. I-ol exerted a very highly significant antitumour effect against hepatocellular HepG2 cells. Cell viability was reduced in a dose-dependent manner, with only the highest doses causing a cytotoxic effect associated with caspase 3/7 activation. Comparable results were obtained for the model colorectal adenocarcinoma cell line, DLD-1, whose tumorigenesis is also associated with CYP2E1. Transcriptome analyses showed a clear effect of I-ol on apoptosis and cell-cycle regulation, with the increased expression of p27Kip1 being particularly noticeable. These observations were confirmed at the protein level for HepG2 and DLD-1 cells grafted on a chorioallantoic membrane. Cell-cycle analysis showed a complete loss of proliferating cells with a simultaneous increase in S-phase arrest beginning at a threshold dose of 30 μM. I-ol also reduced xenograft tumour growth in nude mice. This antitumour effect was not associated with tumour cachexia. I-ol was not toxic to healthy tissues or organs. This study demonstrates for the first time the therapeutic effect of the specific CYP2E1 inhibitor I-ol on the tumorigenesis of HCC. Our findings imply that I-ol can potentially be applied therapeutically on patients at the final stage of FLD. © 2021 Torsten Diesinger et al

Zentrum für Innovationskompetenz: Strategische Investitionen zur nachhaltigen Etablierung des ZIK plasmatis : Abschlussbericht zum Forschungsvorhaben mit dem FKZ: 03Z2DS1 ; Projektlaufzeit: 01.07.2013 - 31.01.2014

[no abstract available

The HIPPO Transducer YAP and Its Targets CTGF and Cyr61 Drive a Paracrine Signalling in Cold Atmospheric Plasma-Mediated Wound Healing

Reactive species play a pivotal role in orchestrating wound healing responses. They act as secondary messengers and drive redox-signalling pathways that are involved in the homeostatic, inflammatory, proliferative, and remodelling phases of wound healing. The application of Cold Atmospheric Plasma (CAP) to the wound site produces a profusion of short- and long-lived reactive species that have been demonstrated to be effective in promoting wound healing; however, knowledge of the mechanisms underlying CAP-mediated wound healing remains scarce. To address this, an in vitro coculture model was used to study the effects of CAP on wound healing and on paracrine crosstalk between dermal keratinocytes and fibroblasts. Using this coculture model, we observed a stimulatory effect on the migration ability of HaCaT cells that were cocultured with dermal fibroblasts. Additionally, CAP treatment resulted in an upregulation of the HIPPO transcription factor YAP in HaCaTs and fibroblasts. Downstream effectors of the HIPPO signalling pathway (CTGF and Cyr61) were also upregulated in dermal fibroblasts, and the administration of antioxidants could inhibit CAP-mediated wound healing and abrogate the gene expression of the HIPPO downstream effectors. Interestingly, we observed that HaCaT cells exhibited an improved cell migration rate when incubated with CAP-treated fibroblast-conditioned media compared to that observed after incubation with untreated media. An induction of CTGF and Cyr61 secretion was also observed upon CAP treatment in the fibroblast-conditioned media. Finally, exposure to recombinant CTGF and Cyr61 could also significantly improve HaCaT cell migration. In summary, our results validated that CAP activates a regenerative signalling pathway at the onset of wound healing. Additionally, CAP also stimulated a reciprocal communication between dermal fibroblasts and keratinocytes, resulting in improved keratinocyte wound healing in coculture. © 2020 Debarati Shome et al