Reactive Oxygen And Nitrogen Species Research Articles

Biocompatible plasma-treated liquids: A sustainable approach for decontaminating gastrointestinal-infection causing pathogens

Nosocomial infections are a serious threat and difficult to cure due to rising antibiotic resistance in pathogens and biofilms. Direct exposure to cold atmospheric plasma (CAP) has been widely employed in numerous biological research endeavors. Nonetheless, plasma-treated liquids (PTLs) formulated with physiological solutions may offer additional benefits such as enhanced portability, and biocompatibility. Additionally, CAP-infused long-lived reactive oxygen and nitrogen species (RONS) such as nitrite (NO2−), nitrate (NO3−), and hydrogen peroxide (H2O2) can synergistically induce their antibacterial activity. Herein, we investigated those argon-plasma jet-treated liquids, including Ringer’s lactate (RL), phosphate-buffered saline (PBS), and physiological saline, have significant antibacterial activity against nosocomial/gastrointestinal-causing pathogens, which might be due to ROS-mediated lipid peroxidation. Combining the conventional culture-based method with propidium iodide monoazide quantitative PCR (PMAxx™-qPCR) indicated that PTLs induce a minimal viable but non-culturable (VBNC) state and moderately affect culturable counts. Specifically, the PTL exposure resulted in pathogenicity dysfunction via controlling T3SS-related effector genes of S. enterica. Overall, this study provides insights into the effectiveness of PTLs for inducing ROS-mediated damage, controlling the virulence of diarrheagenic bacteria, and modulating homeostatic genes.

Plasma-deposited reactive species assisted synthesis of colloidal zinc-oxide nanostructures

A surface-wave microwave discharge is applied to deposit reactive oxygen and nitrogen species (RONS) into the liquid subsequently used as a medium for laser ablation of a Zn metallic target. It is shown that during laser ablation in plasma-treated liquids the H2O2 concentration decreases, while in deionized water (DIW) significant H2O2 is produced. Meanwhile, the pH—initially adjusted by applying reductive metals—increases in the acidic liquids and decreases in the alkaline ones. During months of storage the pH of colloids stabilize around pH 6, which insures the long-term stability of RONS. It is demonstrated that in DIW metallic Zn NPs are created, which gradually oxidize during storage, while in the plasma-treated liquids ZnO NPs are produced with the mean size of 18 nm. In the alkaline plasma-treated liquid the NPs form large aggregates, which slows the dissolution of NPs. In the acidic and neutral solutions besides NPs nanosheets are also formed, which during storage evolve into nanosheet networks as a result of the dissolution of NPs. The band gap of the colloidal ZnO is found to decrease with the formation of aggregates and nanosheet networks. The ZnO NPs ablated in plasma-treated liquids exhibit a high-intensity visible emission covering the green-to-red spectral region. The photoluminescence spectra is dominated by the orange-red emission—previously not detected in the case of laser-ablated ZnO NPs and attributed to the interstitial Zn and oxygen sites—and the yellow emission, which can be attributed to the OH groups on the surface. It is shown that during months of storage, due to the dissolution of NPs and formation of nanosheets, the intensity of the visible emission decreases and shifts to the blue-green spectral region.

Melanin nanoparticles scavenging reactive oxygen and nitrogen radicals for rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is a complex and chronic disease that often causes long-term pain and joint swelling in patients, and even causes joint deformity and dysfunction. The pathogenesis of this disease involves abnormal activity of the immune system, causing immune cells to attack the bodys joint tissues, which triggers an inflammatory response. During these inflammatory processes, the accumulation of reactive oxygen and nitrogen species (RONS) is considered to be one of the key factors that aggravate inflammation and damage joint tissues. To address this problem, we designed a method that takes advantage of the targeting properties of melanin nanoparticles. These nanoparticles have excellent biocompatibility, can remain stable in the body, and can be accurately targeted to the site of inflammation. In addition, these nanoparticles also have strong free radical scavenging ability, which can effectively neutralize excessive RONS, reduce the inflammatory response and weaken joint tissue damage. The promise of this treatment strategy is encouraging and offers new hope for patients with RA. By reducing inflammation, protecting joint tissue, and possibly even reversing the disease process to some extent, this melanin nanoparticle holds great promise.

Evaluation of degradation efficacy and toxicity mitigation for 4-nitrophenol using argon and air-mixed argon plasma jets

This paper investigates the effects of argon (Ar) and that of Ar mixed with ambient air (Ar–Air) cold plasma jets (CPJs) on 4-nitrophenol (4-NP) degradation using low input power. The introduction of ambient air into the Ar-Air plasma jet enhances ionization-driven processes during high-voltage discharge by utilizing nitrogen and oxygen molecules from ambient air, resulting in increased reactive oxygen and nitrogen species (RONS) production, which synergistically interacts with argon. This substantial generation of RONS establishes Ar–Air plasma jet as an effective method for treating 4-NP contamination in deionized water (DW). Notably, the Ar-Air plasma jet treatment outperforms that of the Ar jet. It achieves a higher degradation rate of 97.2% and a maximum energy efficiency of 57.3 gkW−1h−1, following a 6-min (min) treatment with 100 mgL−1 4-NP in DW. In contrast, Ar jet treatment yielded a lower degradation rate and an energy efficiency of 75.6% and 47.8 gkW−1h−1, respectively, under identical conditions. Furthermore, the first-order rate coefficient for 4-NP degradation was measured at 0.23 min−1 for the Ar plasma jet and significantly higher at 0.56 min−1 for the Ar–Air plasma jet. Reactive oxygen species, such as hydroxyl radical and ozone, along with energy from excited species and plasma-generated electron transfers, are responsible for CPJ-assisted 4-NP breakdown. In summary, this study examines RONS production from Ar and Ar–Air plasma jets, evaluates their 4-NP removal efficacy, and investigates the biocompatibility of 4-NP that has been degraded after plasma treatment.

Nitric Oxide Water-driven Immunogenic Cell Death: Unfolding Mitochondrial Dysfunction's Role in Sensitizing Lung Adenocarcinoma to Ferroptosis and Autophagic Cell Death

Non-small cell lung cancer (NSCLC), particularly lung adenocarcinoma (LUAD), significantly influences cancer-related mortality and is frequently considered by poor therapeutic responses due to genetic alterations. Cancer cells possess an inclination to develop resistance to individual treatment modalities, thus it is necessary to investigate several pathways simultaneously to obtain insights that will aid in the establishment of improved therapeutic approaches. Exploring regulated cell death (RCD) mechanisms offers promising avenues to augment immunotherapy by reshaping the tumor microenvironment (TME). Here, we investigated the prospective of microwave plasma-infused Nitric oxide water (NOW) to initiate immunogenic cell death (ICD) while concurrently modulating autophagy and ferroptosis signaling in LUAD-associated A549 cells. Plasma-treatment results in stable NO species nitrite/nitrate (NO2−/NO3-) in the water, altering its physiochemical properties. Analysis of ICD markers reveals increased expression of damage-associated molecular patterns (DAMPs) at both protein and mRNA levels post-NOW exposure. Intracellular reactive oxygen and nitrogen species (RONS) accumulation suggests NO-mediated mitochondrial dysfunction, triggering autophagy induction. Flow cytometry and western blotting confirm alterations in autophagy regulators Beclin-1 and SQSTM1. Furthermore, NOW treatment induces lipid peroxidation and upregulates ferroptosis-associated genes, as determined by qRT-PCR. Transmission electron microscopy (TEM) imaging reveals autophagosome formation and loss of cristae structures, corroborating the occurrence of autophagy and ferroptosis. Our findings propose that NOW may considered as as inducer of ICD and the stimulation of other RCD related protiend may enhance the anti-tumor immunogenicity.

Essential oil and fenchone extracted from Tetradenia riparia (Hochstetter.) Codd (Lamiaceae) induce oxidative stress in Culex quinquefasciatus larvae (Diptera: Culicidae) without causing lethal effects on non-target animals.

We investigated the larvicidal activity of the essential oil (EO) from Tetradenia riparia and its majority compound fenchone for controlling Culex quinquefasciatus larvae, focusing on reactive oxygen and nitrogen species (RONS), catalase (CAT), glutathione S-transferase (GST), acetylcholinesterase (AChE) activities, and total thiol content as oxidative stress indicators. Moreover, the lethal effect of EO and fenchone was evaluated against Anisops bouvieri, Diplonychus indicus, Danio rerio, and Paracheirodon axelrodi. The EO and fenchone (5 to 25µg/mL) showed larvicidal activity (LC50 from 16.05 to 18.94µg/mL), followed by an overproduction of RONS, and changes in the activity of CAT, GST, AChE, and total thiol content. The Kaplan-Meier followed by Log-rank (Mantel-Cox) analyses showed a 100% survival rate for A. bouvieri, D. indicus, D. rerio, and P. axelrodi when exposed to EO and fenchone (262.6 and 302.60µg/mL), while α-cypermethrin (0.25µg/mL) was extremely toxic to these non-target animals, causing 100% of death. These findings emphasize that the EO from T. riparia and fenchone serve as suitable larvicides for controlling C. quinquefasciatus larvae, without imposing lethal effects on the non-target animals investigated.

Low-temperature plasma jet suppresses bacterial colonisation and affects wound healing through reactive species.

An argon-based low-temperature plasma jet (LTPJ) was used to treat chronically infected wounds in Staphylococcus aureus-laden mice. Based on physicochemical property analysis and in vitro antibacterial experiments, the effects of plasma parameters on the reactive nitrogen and oxygen species (RNOS) content and antibacterial capacity were determined, and the optimal treatment parameters were determined to be 4 standard litre per minute and 35 W. Additionally, the plasma-treated activation solution had a bactericidal effect. Although RNOS are related to the antimicrobial effect of plasma, excess RNOS may be detrimental to wound remodelling. In vivo studies demonstrated that medium-dose LTPJ promoted MMP-9 expression and inhibited bacterial growth during the early stages of healing. Moreover, LTPJ increased collagen deposition, reduced inflammation, and restored blood vessel density and TGF-β levels to normal in the later stages of wound healing. Therefore, when treating chronically infected wounds with LTPJ, selecting the medium dose of plasma is more advantageous for wound recovery. Overall, our study demonstrated that low-temperature plasma jets may be a potential tool for the treatment of chronically infected wounds.

A Two-Stage Transferred Cold Atmospheric Plasma as a Unique Therapeutic Strategy for Targeting Colon Cancer Stem Cells

The study examines the induction of apoptosis in colon cancer stem cells (CCSCs) within a 3D culture setting, employing an innovative cold atmospheric plasma (CAP) transmission method known as TS-TCAP. TS-TCAP is a partially or fully ionized non-thermal gaseous mixture that comprises photons, charged and neutral particles, and free radicals, which has gained traction in biomedical applications such as cancer therapy. TS-TCAP impacts CCSCs via a continuous, two-step transport process, facilitating the efficient delivery of reactive oxygen and nitrogen species (RONS). The key cellular factors of CCSCs impacted by TS-TCAP treatment, encompassing the secretion and expression levels of IL-6 and IL-8, apoptotic cell count, and expression of BAX, BCL-2, and KI-67 proteins, were evaluated using qrt-ELISA, Annexin V, and qrt-PCR procedures, respectively. The outcomes of CCSCs treatment with TS-TCAP reveal a notable rise in the number of apoptotic cells (p value <0.0001), diminished secretion, and gene expression of IL-6 and IL-8 (p-value < 0.0001), accompanied by favorable alterations in BCL-2 and BAX gene expression (p value <0.0001). Additionally, a notable decrease in KI-67 expression was observed, correlating with a reduction in CCSCs proliferation (p value <0.0001). As well, this study underscores the anti-cancer potential of TS-TCAP, showcasing its efficacy in reducing CCSCs survival rates. However, further pre-clinical and clinical trials are necessary to evaluate CAP's efficacy, safety, and potential synergistic effects with other therapies thoroughly. Overall, TS-TCAP presents a promising alternative for CCSCs treatment, pending further investigation and refinement.

Leveraging Plasma-Activated Seawater for the Control of Human Norovirus and Bacterial Pathogens in Shellfish Depuration.

Cold plasma is a promising alternative for water treatment owing to pathogen control and a plethora of issues in the agriculture and food sectors. Shellfish pose a serious risk to public health and are linked to large viral and bacterial outbreaks. Hence, current European regulations mandate a depuration step for shellfish on the basis of their geographical growth area. This study investigated the inactivation of relevant viral and bacterial pathogens of three plasma-activated seawaters (PASWs), and their reactive oxygen and nitrogen species (RONS) composition, as being primarily responsible for microbial inactivation. Specifically, F-specific (MS2) and somatic (φ174) bacteriophage, cultivable surrogate (murine norovirus, MNV, and Tulane virus, TV), and human norovirus (HuNoV GII.4) inactivation was determined using plaque counts and infectivity assays, including the novel human intestinal enteroid (HIE) model for HuNoV. Moreover, the kinetic decay of Escherichia coli, Salmonella spp., and Vibrio parahaemolyticus was characterized. The results showed the complete inactivation of phages (6-8 log), surrogates (5-6 log), HuNoV (6 log), and bacterial (6-7 log) pathogens within 24 h while preventing cytotoxicity effects and preserving mussel viability. Nitrites (NO2-) were found to be mostly correlated with microbial decay. This research shows that PASWs are a suitable option to depurate bivalve mollusks and control the biohazard risk linked to their microbiological contamination, either viral or bacterial.

DBD plasma as a practical approach to sterilization of dental instruments

Microbe control and decontamination are necessary for medical equipment that will be used again. Several wet and dry sterilizer technologies, like as autoclaves, ovens, UV systems, and chemical agents, have been widely used to eliminate the possibility of cross-infection between contaminated dental instruments or materials and dental patients. The development of a sterilizer device capable of sterilizing dental equipment through non-toxic materials has been shown to significantly decrease the overall procedure time compared to conventional approaches. Therefore, an investigation was conducted to assess the efficacy of a dielectric barrier discharge (DBD) plasma device in sterilizing dental instruments under atmospheric pressure conditions. Also, due to Reactive Oxygen and Nitrogen Species (RONS) existence at low temperatures, researchers have been examining the biological effects of cold plasmas for medical applications with promising results. The dental Tweezer, one of the dental tools, was chosen to perform the sterilization process using the DBD plasma device. The Dental Tweezers samples were contaminated with Escherichia coli and Staphylococcus aureus bacteria, and then the DBD plasma device was used to sterilize them for 1, 2, 3, and 4 min, respectively, to figure out the best time to do this. The DBD plasma device successfully killed E. coli and S. aureus. Based on the findings derived from our present investigation, the cold plasma device has impressively proven its efficiency in sterilization.

Abstract B030: Synergistic antitumor effects of cold atmospheric plasma and temozolomide in glioblastoma: multimodal approaches integrating in-vitro, in vivo, and in silico investigations for novel and enhanced therapeutic advancements

Abstract Glioblastoma multiforme (GBM) is a common and aggressive brain cancer with a median survival rate of 12 to 18 months after diagnosis. Despite standard treatments, including surgery, radiotherapy, and Temozolomide (TMZ), GBM remains highly resistant to therapy due to its infiltrative pattern of invasion, rapid growth, and propensity to relapse [1]. While overall mortality rates remain high, there is a crucial need for a better understanding of the molecular mechanisms and gene mutations involved in GBM and the development of more effective and adaptive therapeutic approaches. Modulating reactive oxygen species (ROS) levels has been suggested as a therapeutic strategy to selectively target the destruction of cancer cells. To address this, we propose a combination therapy utilizing multi-operational plasma devices, including using cold atmospheric plasma (CAP) jet and plasma discharge tube (PDT) in conjunction with TMZ for GBM treatment. CAP functions by elevating reactive oxygen and nitrogen species (RONS) levels and specifically targeting tumor spread. We investigated various plasma devices and their characteristics using optical emission spectroscopy (OES) and measured the electromagnetic potential and emissions of the PDT. The OES of PDT displayed a similar spectrum as the CAP jet, indicating the presence of ROS. In this study, we performed transcriptomic analysis of glioblastoma cells using high throughput deep RNA-Seq with next-generation sequencing (NGS) to quantify genome-wide gene expression changes. Additionally, we examined signaling pathways and predicted structural changes in consequential proteins caused by gene spectrum up or down-regulation. Our results demonstrate that the combination treatment of CAP and TMZ downregulated vital genes involved in MAPK, P53, DNA repair, and cell cycle pathways. The combination of CAP & TMZ showed a significant antitumor effect, inducing apoptosis and damaging essential proteins in GBM cells. In vitro and microscopic studies verified these results, showing nuclear and cell membrane disruption in cancer cells post-plasma treatment. Our findings demonstrate that the combination of CAP/PDT and TMZ effectively sensitizes GBM cells to TMZ, leading to apoptosis. We have previously shown a non-invasive application of CAP jet on the skull of tumor-bearing mice causing ~78% tumor inhibition [2]. Our current study highlights the potential of PDT for non-invasive treatment in vitro, offering a modality for intracranial delivery in in-vivo models. In conclusion, we propose CAP/PDT and TMZ combination therapy as novel non-invasive treatments for GBM in murine models. This approach offers a promising avenue for addressing the dire need for more effective treatments with minimal impact on normal cells. Further investigations and validation in clinical settings are warranted to significantly improve GBM management and patient outcomes.

Effect of acute cadmium exposure on oxidative stress and antioxidant system of the scallop Aequipecten tehuelchus

This study aimed to assess the impact of acute exposure (96 h) to Cd in gills, digestive gland and muscle of the Tehuelche scallop Aequipecten tehuelchus from San José gulf in Patagonia, Argentina. Scallops were exposed to Cd concentrations of 0, 25, 50, 100, 150, 204, 275, 371, and 500 μg/L, and mortality rates were recorded after 96 h of exposure. Surviving organisms were analyzed for the biochemical response through reactive oxygen and nitrogen species (RONS), activities of catalase (CAT) and glutathione-S-transferase (GST), metallothioneins (MT), lipid peroxidation (LPO) and liposoluble antioxidants α-tocopherol (α-T) and β-carotene (β-C). The mean lethal concentration (LC50) was 155.8 μg Cd/L, a lower value than other scallops' species, showing that A. tehuelchus has a particular sensitivity to Cd. In the three tissues, at all exposure concentrations, there was no significant response in RONS levels, GST activity or LPO. Nevertheless, CAT activity and α-T levels decreased in the gills but increased in the digestive gland, with no significant response in the muscle. Two-way ANOVA revealed a significant interaction between Cd concentration and tissue on MT, which increased significantly in gills, decreased in digestive gland with 100 compared to 50 μg Cd/L; whereas in muscle a significant increase was observed with 25 μg Cd/L compared to control. The results show a significant effect of Cd in scallop's gills on CAT activity and α-T levels, highlighting this tissue as the primary target against relevant concentrations of metal in seawater. The effect on digestive gland and muscle was minimal. The overall results suggest that Cd toxicity is tissue-specific. This study will help reduce the existence knowledge gap regarding potential impacts of acute exposure to Cd in a bivalve species with high ecological and commercial importance, as well as identifying the most responsive biomarkers associated with Cd stress for monitoring assessment.

Tannic acid and zinc ion coordination of nanase for the treatment of inflammatory bowel disease by promoting mucosal repair and removing reactive oxygen and nitrogen species

Colon mucosal overexpression of reactive oxygen and nitrogen species (RONS) accelerates the development of inflammatory bowel disease (IBD) and destroys the mucosa and its barrier. IBD can be alleviated by removing RONS from the inflamed colon. The preparation of strong and efficient nanoantioxidants remains a challenge despite the development of numerous nanoantioxidants. In this paper, Zn-TA nanoparticles with fine hollow microstructure (HZn-TA) were successfully prepared and could be effectively used to treat IBD. In the first step, ZIF-8 nanoparticles were synthesized by a one-pot method. On this basis, HZn-TA nanoparticles were etched by TA, and a multifunctional nanase was developed for the treatment of IBD. RONS, including reactive oxygen species (ROS) and nitric oxide (NO), can be eliminated to increase cell survival following Hydrogen peroxide (H2O2) stimulation, including reactive oxygen species (ROS) and nitric oxide (NO with hydrogen peroxide (H2O2). In a model for preventing and delaying acute colitis, clearance of RONS has been shown to reduce intestinal inflammation in mice by reducing colon damage, proinflammatory cytokine levels, the spleen index, and body weight. Intestinal mucosal healing can be promoted by HZn-TA nanoparticles, which can upregulate zonula occludens protein 1 (ZO-1) and claudin-1 expression. Based on the results of this study, HZn-TA nanoparticles were able to effectively treat IBD with minimal adverse effects by being biocompatible, multienzyme active, and capable of scavenging RONS. Therefore, we pioneered the application of HZn-TA nanoparticles for the treatment of IBD, which are capable of clearing RONS without significant adverse effects. Statement of significance➢ HZn-TA nanoparticles were successfully prepared and could be effectively used to treat IBD.➢ Intestinal mucosal healing can be promoted by HZn-TA nanoparticles, which can upregulate ZO-1 and claudin-1 expression.➢ HZn-TA nanoparticles were able to effectively treat IBD with minimal adverse effects by being biocompatible, multienzyme active, and capable of scavenging RONS.

Molecular mechanism of cleavage of SARS-CoV-2 spike protein by plasma generated RONS

Recently, it is been shown that cold atmospheric pressure plasmas Cold Atmospheric Plasma effectively inactivate the 2019-nCoV virus. Despite this promising finding, the precise mechanism of this inactivation remains unclear due to the limited number of studies conducted on the subject. Consequently, this paper focuses on the spike protein, a crucial part of the novel coronavirus, and the various reactive oxygen and nitrogen species (RONS) generated by the plasma. The study employs reactive molecular dynamics simulation and ReaxFF potential to explore the reactions between the spike protein molecules and different reactive oxygen nitrogen species (including H2O2, OH, O, O3, HOONO, and 1O2). The findings suggest that when a single RONS interacts with the spike protein, 1O2 and HOONO have the most potent ability to sever the spike protein. Additionally, the combined effect of long-lived and short-lived RONS presents a more potent decomposition impact.

Three-Step Depletion Strategy of Glutathione: Tunable Metal-Organic-Framework-Engineered Nanozymes for Driving Oxidative/Nitrative Stress to Maximize Ferroptosis Therapy.

Ferroptosis is a novel type of nonapoptotic programmed cell death involving the accumulation of lipid peroxidation (LPO) to a lethal threshold. Herein, we propose tunable zeolitic imidazolate framework (ZIFs)-engineered biodegradable nanozymes for ferroptosis mediated by both reactive oxygen species (ROS) and nitrogen species (RNS). l-Arginine is utilized as an exogenous nitric oxide donor and loaded into hollow ZIFs@MnO2 artificial nanozymes, which are formed by etching ZIFs with potassium permanganate and simultaneously generating a MnO2 shell in situ. The constructed nanozymes with multienzyme-like activities including peroxidase, oxidase, and catalase can release satisfactory ROS and RNS through a cascade reaction, consequently promoting the accumulation of LPO. Furthermore, it can improve the efficiency of ferroptosis through a three-step strategy of glutathione (GSH) depletion; that is, the outer MnO2 layer consumes GSH under slightly acidic conditions and RNS downregulates SLC7A11 and glutathione reductase, thus directly inhibiting GSH biosynthesis and indirectly preventing GSH regeneration.

Kinetic model of grating-like DBD fed with flowing humid air

This work proposes a coupled kinetic model to capture the spatiotemporal evolution behaviors of reactive species generated by a grating-like dielectric barrier discharge (DBD) operated in flowing humid air. The coupled model incorporates a zero-dimensional (0D) discharge model for the discharge filament and a 0D kinetic model or two-dimensional (2D) fluid model for the afterglow region. The model is experimentally validated by the ozone measurements under different airflow rates and power levels. With the pseudo-1D plug flow approximation, the spatial distribution of species obtained by the 0D afterglow model agrees well with the 2D fluid model. The kinetics of reactive oxygen and nitrogen species in the discharge and afterglow region and the underlying pathways are analyzed. It is predicted by the model that there exists an optimal discharge power or airflow rate to acquire a maximum density of short-lived species (OH, O2(a1Δ), HO2, etc) delivered to a given location in the afterglow region. The key factor influencing the plasma chemistry is discharge power, regardless of initial species density, and less concerned with pulse width. The proposed model provides hints for a better understanding of DBD-relevant plasma chemistry operated in ambient air.

The biological effect of the physical energy of plasma

Since the publication of the initial paper on atmospheric pressure plasma sterilization by Dr Laroussi in 1996, researchers have contributed to the field with an extensive number of papers on plasma medicine. However, these studies have primarily concentrated on the biological impacts of the chemical reactive components generated by plasma, specifically focusing on the effects of reactive oxygen and nitrogen species. Conversely, when plasma directly interacts with biological organisms, there are additional physical energies involved, such as electric fields, ultraviolet (UV)/vacuum ultraviolet (VUV) radiation, heat, etc., which may also play crucial roles in their interaction. This paper delves into this aspect by using the simplest bactericidal effect as a model for biological effects. Three dielectrics—Al2O3, quartz, and MgF2 glass—are employed to isolate the chemical active components, enabling the examination of the bactericidal effects of the electric field, UV, and VUV, respectively. The findings indicate that the plasma-induced electric field can induce irreversible electroporation, effectively eliminating bacteria at 27 kV cm−1. Notably, at a plasma-induced electric field of 40 kV cm−1, sterilization efficiency experiences a significant enhancement. The bactericidal effects of UV and VUV are closely linked to the choice of the plasma’s working gas. Specifically, when Ar is the working gas, the bactericidal effect of UV surpasses that of using only the plasma-induced electric field by two orders of magnitude, while using He results in only a one-order increase. Despite VUV radiation being considerably weaker than UV, its bactericidal effect remains substantial. In instances where He plasma is utilized, the addition of VUV doubles the bactericidal effect. In short, this paper pioneers the exploration of the biological effects of plasma’s physical energy, providing essential insights for the advancement of plasma medicine.

Cold atmospheric plasma (CAP) treatment increased reactive oxygen and nitrogen species (RONS) levels in tumor samples obtained from patients with low-grade glioma

Low-grade gliomas (LGGs) are a heterogeneous group of tumors with an average 10-year survival rate of 40%–55%. Current treatment options include chemotherapy, radiotherapy, and gross total resection (GTR) of the tumor. The extent of resection (EOR) plays an important role in improving surgical outcomes. However, the major obstacle in treating low-grade gliomas is their diffused nature and the presence of residual cancer cells at the tumor margins post resection. Cold Atmospheric Plasma (CAP) has shown to be effective in targeted killing of tumor cells in various glioma cell lines without affecting non-tumor cells through Reactive Oxygen and Nitrogen Species (RONS). However, no study on the effectiveness of CAP has been carried out in LGG tissues till date. In this study, we applied helium-based CAP on tumor tissues resected from LGG patients. Our results show that CAP is effective in promoting RONS accumulation in LGG tissues when CAP jet parameters are set at 4 kV voltage, 5 min treatment time and 3 lpm gas flow rate. We also observed that CAP jet is more effective in thinner slice preparations of tumor as compared to thick tumor samples. Our results indicate that CAP could prove to be an effective adjunct therapy in glioma surgery to target residual cancer cells to improve surgical outcome of patients with low-grade glioma.

Inactivation mechanism and kinetics of dielectric barrier discharge plasma against Escherichia coli O157:H7 in phosphate-buffered saline

ABSTRACT This study investigated the inactivation mechanism and kinetics of dielectric barrier discharges (DBD) plasma against Escherichia coli O157:H7. DBD plasma exhibited a remarkable bactericidal effect, and the inactivation kinetics was well described with the Weibull model. Using the ambient air as the working gas, surviving E. coli O157:H7 in phosphate-buffered saline achieved an undetectable level (<10 CFU/mL) after treatment at 18 W for 60 s. DBD plasma altered cell morphology, destructed both the outer and inner membranes, and increased intracellular reactive oxygen species levels. Moreover, DBD plasma significantly decreased the pH of the suspended medium, and increased its oxidation reduction potential and active species levels, which could be mainly responsible for microbial inactivation. The presence of glutathione or N-acetyl-L-cysteine weakened the antibacterial activity of DBD plasma due to their reactive oxygen and nitrogen species (RONS) scavenging capacity, demonstrating that RONS generated by DBD plasma played important roles in decontamination.

Delivery Systems for Plasma-reactive Species and their Applications in the Field of Biomedicine.

Cold atmospheric plasma (CAP) is an ionized matter with potential applications in various medical fields, ranging from wound healing and disinfection to cancer treatment. CAP's clinical usefulness stems from its ability to act as an adjustable source of reactive oxygen and nitrogen species (RONS), which are known to function as pleiotropic signaling agents within cells. Plasma-activated species, such as RONS, have the potential to be consistently and precisely released by carriers, enabling their utilization in a wide array of biomedical applications. Furthermore, understanding the behavior of CAP in different environments, including water, salt solutions, culture medium, hydrogels, and nanoparticles, may lead to new opportunities for maximizing its therapeutic potential. This review article sought to provide a comprehensive and critical analysis of current biomaterial approaches for the targeted delivery of plasma-activated species in the hope to boost therapeutic response and clinical applicability.