Effect Of Non-thermal Plasma Research Articles

Synergistic Effects of Nonthermal Plasma and Solid Acid Catalysts in Thermo-Catalytic Glycerol Dehydration

To enhance the bio-based synthesis of acrolein from glycerol, a hybrid approach combining in situ nonthermal plasma (NTP) with thermo-catalytic dehydration was employed. This study investigated the impact of the reaction temperature and NTP discharge field strength on glycerol conversion, acrolein selectivity, byproduct formation, and coke deposition using two catalysts of silicotungstic acid supported on mesoporous alumina and silica. The results revealed that, while the reaction temperature and NTP field strength exhibited complex interactions, the in situ application of NTP markedly improved both glycerol conversion and acrolein selectivity when optimized for specific temperature–NTP field strength combinations. Additionally, the reaction mechanisms of glycerol dehydration with the two catalysts, in the presence and absence of NTP, were systematically analyzed and discussed based on the experimental data.

Determining the Effect of Non-Thermal Plasma on the Transmembrane Kinetics of Melittin through Molecular Explorations.

Non-thermal plasma (NTP) synergistic anticancer strategies are a current hotspot of interest at the intersection of plasma biomedicine. Melittin (MEL) has been shown to inhibit cancer in many malignant tumors; however, its clinical application is controversial. Therefore, the transmembrane process and mechanism of MEL activity in different cell systems were studied and the combination of MEL and NTP was proposed in this paper. The results showed that the electrostatic attraction between MEL and the lipid bilayer contributes to the stable orientation of MEL on the membrane surface. In addition, sialic acid overexpression affects the degree to which MEL binds the membrane system and the stability of the membrane structure. The use of NTP to reduce the dosage of MEL and its related nonspecific cytolysis activity has certain clinical application value. The results of this study provide theoretical support for improving the clinical applicability of MEL and contribute to the further development of plasma biomedicine.

Abatement and biotoxicity assessment of chlorpyrifos residue from green coffee beans: Effect of non-thermal plasma generated ozone and nitric oxide species

Chlorpyrifos (CP) is an organophosphate pesticide (OPP) that is widely used in coffee plantations to mitigate the impacts of insects and maximize productivity. However, the environmental persistence of CP has become an issue. Non-thermal plasma (NTP) generated ozone and nitric oxide (NO) species have demonstrated the ability to remediate organic contaminants and promote plant growth. In this study, the washing of CP-contaminated green coffee beans (GCBs) by using plasma activated water (PAW) via ozone and NO dominated species was investigated, respectively. The results revealed degradation efficiencies of 89 and 87 % for ozone and NO dominated treatment, respectively. The concentration of hydroxyl radicals in ozone plasma-activated water (PAW), crucial for initiating and sustaining CP degradation, decreased from 25 μM after 30 min of treatment to 5 μM after 150 min. The concentration of H2O2 remained steady at 1.6 μM while NO2- concentration increased gradually from 0.37 to 3.06 mM during the treatment. Nevertheless, NO dominated NTP treatment resulted in the darkening of the GCBs, whereas ozone NTP treatment brought no physical changes. Therefore, ozone NTP treatment is recommended for large-scale treatments. Moreover, three degradation mechanisms were proposed based on the identified intermediate products (IPs) from liquid chromatography-mass spectrometry (LC-MS) analysis. The cytotoxic effects of these residual IPs after ozone dominated NTP washing were examined using human colon cancer-derived HT29 cells. The results showed cell viability increased to 90 and 95 % when exposed to ozone NTP-treated GCBs for 90 and 120 min, respectively.

Skin treatment with non-thermal plasma modulates the immune system through miR-223-3p and its target genes

ABSTRACT Non-thermal plasma, a partially ionized gas, holds significant potential for clinical applications, including wound-healing support, oral therapies, and anti-tumour treatments. While its applications showed promising outcomes, the underlying molecular mechanisms remain incompletely understood. We thus apply non-thermal plasma to mouse auricular skin and conducted non-coding RNA sequencing, as well as single-cell blood sequencing. In a time-series analysis (five timepoints spanning 2 hours), we compare the expression of microRNAs in the plasma-treated left ears to the unexposed right ears of the same mice as well as to the ears of unexposed control mice. Our findings indicate specific effects in the treated ears for a set of five miRNAs: mmu-miR-144-5p, mmu-miR-144-3p, mmu-miR-142a-5p, mmu-miR-223-3p, and mmu-miR-451a. Interestingly, mmu-miR-223-3p also exhibits an increase over time in the right non-treated ear of the exposed mice, suggesting systemic effects. Notably, this miRNA, along with mmu-miR-142a-5p and mmu-miR-144-3p, regulates genes and pathways associated with wound healing and tissue regeneration (namely ErbB, FoxO, Hippo, and PI3K-Akt signalling). This co-regulation is particularly remarkable considering the significant seed dissimilarities among the miRNAs. Finally, single-cell sequencing of PBMCs reveals the downregulation of 12 from 15 target genes in B-cells, Cd4+ and Cd8+ T-cells. Collectively, our data provide evidence for a systemic effect of non-thermal plasma.

Plasma water treatment for PFAS: Study of degradation of perfluorinated substances and their byproducts by using cold atmospheric pressure plasma jet

This study evaluates the effectiveness of non-thermal plasma at atmospheric pressure (NTP APPJ) for treating PFAS - contaminated water in different matrices. Successful removal of several perfluoroalkyl carboxylic acids (PFCAs) (C6 to C4), perfluroalkane sulfonic acids (PFSAs) (C8 to C4) and perfluropolyethers (PFPEs) (GenX and ADONA) PFAS compounds was achieved in laboratory scale experiments. In the deionized water (DW), high removal efficiencies (> 90%) were observed for longer-chain PFAS, PFOS (99.89%), PFHxA (94.61%) and ADONA (94.83%), while shorter- chain compounds had lower removal rates. Real water samples (tap water and synthetic effluent) showed lower overall degradation percentages (8–50%) depending on compound and matrix. Short-chain PFAS displayed around 10% removal in tap water, while PFOS and GenX achieved 50% and 32% removal, respectively. Complex matrix effects influence degradation rates. Byproducts from the plasma treatment were investigated, revealing distinct degradation mechanisms for various PFAS compounds. For PFSAs and PFCAs, degradation involved electron transfer, bond breaking and subsequent reactions. Conversely, ADONA and GenX degradation initiated with ether-group cleavage, followed by additional transformation processes. Plasma-based technology shows potential for degradation of PFAS, especially for newer substitute compounds like ADONA and GenX. However, further research is needed to optimize plasma performance for complete mineralization of PFAS. This study also proposes a degradation mechanism for ADONA, marking a novel investigation into ether-group PFAS degradation with potential implications for further research and understanding toxicological implications.

Enhancing the Production of Eco-Friendly Silk Fabrics through the Application of Nonthermal Plasma Wettability Techniques.

The combination of the effects of nonthermal plasma using atmospheric pressure of plasma jet and the photocatalytic effects of titanium dioxide nanoparticles was used to study the plasma flow modes, electrical characteristics, nonthermal characteristics, antimicrobial measurements, and surface modifications. Using different wettabilities of argon discharges in a laminar flow: (i) wet I, wettability with 2.4 slm argon mixture with oxygen ratio O2, equivalent to 15 mslm (Ar/O2), and (ii) wet II, wettability (Ar/O2) mixture combined with titanium dioxide, to accelerate the inactivation process on the nonwoven fabric surface. For wet 0, wet I, and wet II discharges, the average rate of heat transfer to the nonwoven silk fabric increased significantly. Specifically, it goes from 104.6 to 118.6 and then to 241.7 mW, respectively. The kinetic deactivation rate of Escherichia coli increases starting at 0.20, then going up to 0.32, and finally reaching 0.57 min-1. The increased wettability of the TiO2 photocatalyst results in an enhanced bactericidal rate, which is caused by both the heat impact from the nonthermal jet and potentially photocatalytic disinfection, leading to the generation of active species. The mechanical parameters owing to different wettabilities and plasma interactions with the fabric membrane were tested for the treated samples, such as stiffness, ultimate yield strength, tensile strength, strain, hardening, elongation, resilience, and toughness.

Modeling the growth of Aspergillus brasiliensis affected by a nonthermal plasma.

The main objective of the study was to develop and validate a model for the growth of Aspergillus brasiliensis on surfaces, specifically on agar culture medium. An additional aim was to determine conditions for complete growth inhibition of this micromycete using two different nonthermal plasma (NTP) sources. The developed model uses two key parameters, namely the growth rate and growth delay, which depend on the cultivation temperature and the amount of inoculum. These parameters well describe the growth of A. brasiliensis and the effect of NTP on it. For complete fungus inactivation, a single 10-minute exposure to a diffuse coplanar surface barrier discharge was sufficient, while a point-to-ring corona discharge required several repeated 10-minute exposures at 24-h intervals. The article presents a model for simulating the surface growth of A. brasiliensis and evaluates the effectiveness of two NTP sources in deactivating fungi on agar media.

Assessing the antimicrobial efficacy of nonthermal plasma treatment on filamentous fungi spores and biofilms

With the increasing resistance of biofilms to existing products and their predominantly negative impact on the environment, efforts are being made to find new alternatives to suppress microbial growth. One of them involves the use of a nonthermal plasma (NTP). This physical method of eradicating microbial growth has been well studied in terms of its application to bacteria and yeasts, while the effect of NTP on microscopic filamentous fungi has been neglected. However, NTP could serve as a viable alternative to existing disinfectants within food industry production facilities to eliminate the development of fungal contamination. This study investigates the effect of a NTP on the metabolic activity of spores regrowth and biofilms of filamentous fungi as well as on the morphological changes of microbial cultures after exposure to NTP. The morphological changes have been imaged using the scanning electron microscopy (SEM). It has been shown that high quality SEM images of the fungal spores can be obtained without a conductive coating, but in case of the fungal biofilms the use of the coating was necessary. In all examined microorganisms, the NTP treatment led to a reduction in the extracellular matrix of the biofilm and inflicted damage to the hyphae. Untreated samples displayed a layered biofilm structure, while post-treatment, the structure transitioned to a sparse, monolayered form. Particularly notable morphological alterations in the biofilm, as evidenced by SEM microscopy, were observed in Alternaria alternata. These changes align with the observed decrease in metabolic activity following NTP treatment, which was most prominent in this strain.

Non-Thermal Plasma Reduces HSV-1 Infection of and Replication in HaCaT Keratinocytes In Vitro.

Herpes simplex virus type 1 (HSV-1) is a lifelong pathogen characterized by asymptomatic latent infection in the trigeminal ganglia (TG), with periodic outbreaks of cold sores caused by virus reactivation in the TG and subsequent replication in the oral mucosa. While antiviral therapies can provide relief from cold sores, they are unable to eliminate HSV-1. We provide experimental results that highlight non-thermal plasma (NTP) as a new alternative therapy for HSV-1 infection that would resolve cold sores faster and reduce the establishment of latent infection in the TG. Additionally, this study is the first to explore the use of NTP as a therapy that can both treat and prevent human viral infections. The antiviral effect of NTP was investigated using an in vitro model of HSV-1 epithelial infection that involved the application of NTP from two separate devices to cell-free HSV-1, HSV-1-infected cells, and uninfected cells. It was found that NTP reduced the infectivity of cell-free HSV-1, reduced viral replication in HSV-1-infected cells, and diminished the susceptibility of uninfected cells to HSV-1 infection. This triad of antiviral mechanisms of action suggests the potential of NTP as a therapeutic agent effective against HSV-1 infection.

Nonthermal Atmospheric Pressure Plasma Treatment of Endosteal Implants for Osseointegration and Antimicrobial Efficacy: A Comprehensive Review.

The energy state of endosteal implants is dependent on the material, manufacturing technique, cleaning procedure, sterilization method, and surgical manipulation. An implant surface carrying a positive charge renders hydrophilic properties, thereby facilitating the absorption of vital plasma proteins crucial for osteogenic interactions. Techniques to control the surface charge involve processes like oxidation, chemical and topographical adjustments as well as the application of nonthermal plasma (NTP) treatment. NTP at atmospheric pressure and at room temperature can induce chemical and/or physical reactions that enhance wettability through surface energy changes. NTP has thus been used to modify the oxide layer of endosteal implants that interface with adjacent tissue cells and proteins. Results have indicated that if applied prior to implantation, NTP strengthens the interaction with surrounding hard tissue structures during the critical phases of early healing, thereby promoting rapid bone formation. Also, during this time period, NTP has been found to result in enhanced biomechanical fixation. As such, the application of NTP may serve as a practical and reliable method to improve healing outcomes. This review aims to provide an in-depth exploration of the parameters to be considered in the application of NTP on endosteal implants. In addition, the short- and long-term effects of NTP on osseointegration are addressed, as well as recent advances in the utilization of NTP in the treatment of periodontal disease.

Exploring the effects of non-thermal plasma pre-treatment on coriander (Coriander sativum L.) seed germination efficiency

This study investigates the effects of non-thermal plasma (NTP) treatment on the germination characteristics of coriander seeds (Coriandrum sativum L.). Different germination factors, water imbibition rate and changes in mass, were analyzed. The results indicate that a suitable duration of NTP treatment (180 s and 300 s) enhances seed germination characteristics, whereas prolonged exposure (420 s) leads to adverse effects. Furthermore, shorter NTP exposures (180 s) improved water absorption and surface properties of seeds, while longer exposures (420 s) caused mass loss and compromised seed vigor. Overall, the findings demonstrate the significance of optimizing NTP treatment conditions for enhancing seed germination characteristics.

Synergism of non-thermal plasma and low concentration RSL3 triggers ferroptosis via promoting xCT lysosomal degradation through ROS/AMPK/mTOR axis in lung cancer cells

BackgroundThough (1S, 3R)-RSL3 has been used widely in basic research as a small molecular inducer of ferroptosis, the toxicity on normal cells and poor pharmacokinetic properties of RSL3 limited its clinical application. Here, we investigated the synergism of non-thermal plasma (NTP) and low-concentration RSL3 and attempted to rise the sensitivity of NSCLC cells on RSL3.MethodsCCK-8 assay was employed to detect the change of cell viability. Microscopy and flowcytometry were applied to identify lipid peroxidation, cell death and reactive oxygen species (ROS) level respectively. The molecular mechanism was inspected with western blot and RT-qPCR. A xenograft mice model was adopted to investigate the effect of NTP and RSL3.ResultsWe found the synergism of NTP and low-concentration RSL3 triggered severe mitochondria damage, more cell death and rapid ferroptosis occurrence in vitro and in vivo. NTP and RSL3 synergistically induced xCT lysosomal degradation through ROS/AMPK/mTOR signaling. Furthermore, we revealed mitochondrial ROS was the main executor for ferroptosis induced by the combined treatment.ConclusionOur research shows NTP treatment promoted the toxic effect of RSL3 by inducing more ferroptosis rapidly and provided possibility of RSL3 clinical application.Graphical DeK3en8zu4Ed_UHNNMi2cXVideo

Effect of Non-thermal Plasma Therapy on Pushout Bond Strength of Epoxy Resin and Tricalcium Silicate-Based Endodontic Sealers.

Introduction: The current study aimed to assess the effect of non-thermal plasma (NTP) on the pushout bond strength (PBS) of epoxy resin and tricalcium silicate-based endodontic sealers. Methods: Forty single-canal extracted teeth were decoronated at the coronal region, underwent root canal preparation, and were assigned to four groups (n=10) for the application of AH26 sealer, NTP+AH26 (P-AH26), Endoseal TCS sealer, and NTP+Endoseal TCS sealer (P-TCS). The root canals were sectioned into 1 mm slices, and the PBS value was measured in a universal testing machine. Data were analyzed by the Friedman, Kruskal-Wallis, and Dunn tests (P<0.05). Results: The PBS of TCS and P-TCS groups was not significantly different (P>0.05). The PBS of the P-AH26 group was significantly lower than that of the AH26 group in the middle third (P<0.05). The PBS of the AH26 group was higher than the other groups in all sections. The PBS in the apical third was lower than other sections in all groups (P<0.05). Conclusion: NTP had no significant effect on the PBS of Endoseal TCS. NTP significantly decreased the PBS of AH26 sealer in the middle third but had no significant effect on its bond strength in other sections.

Effects of Non-Thermal Plasma on the Transition from Nano-Crystalline to Amorphous Structure in Water and Subsequent Effects on Viscosity

Recent studies have demonstrated that the physical properties of water treated with non-thermal plasma, or plasma-activated water (PAW), significantly differ from those of distilled water. For example, contrary to expectation, the viscosity of PAW becomes lower than that of distilled water at certain temperatures. This study developed a model to explain these differences by combining the two-state model of ordinary water, which describes water as a combination of nano-crystalline clusters and amorphous, free-floating molecules, using the Debye–Huckel theory for a fluid containing ions. A model for the viscosity of PAW was then developed from the general model. It explains how PAW has a lower viscosity than distilled water as the temperature decreases and why this effect is stronger than the colligative effect for ideal solutions. Finally, the viscosity model is compared to the experimental measurements of PAW treated with gliding arc plasma, showing that the data match the predicted values quite well. The model of PAW developed here can be used to understand other physical properties beyond viscosity, such as the surface tension, contact angle, electric conductivity, heat capacity, isothermal compressibility, and density, potentially facilitating new applications of PAW.

A Study on the Effect of Non-thermal Plasma on Macrophage Phenotype Modulation

A Study on the Effect of Non-thermal Plasma on Macrophage Phenotype Modulation

Non-thermal plasma disinfecting procedure is harmless to delicate items of everyday use

Non-thermal plasma (NTP) is a well-known decontamination tool applicable for a wide range of microorganisms and viruses. Since the recent COVID-19 pandemic highlighted the need to decontaminate all daily used items, it is highly desirable to address the applicability of NTP, including its possible harmful effects. To the best of our knowledge, a comprehensive characterization of NTP effects on sensitive materials is still lacking. We investigated the potential damage to common materials of daily use inflicted by air atmospheric NTP generated in Plasmatico v1.0. The materials tested were paper, various metals, and passive and active electronic components modelling sensitive parts of commonly used small electronic devices. The NTP-exposed paper remained fully usable with only slight changes in its properties, such as whitening, pH change, and degree of polymerization. NTP caused mild oxidation of copper, tinned copper, brass, and a very mild oxidation of stainless steel. However, these changes do not affect the normal functionality of these materials. No significant changes were observed for passive electronic components; active components displayed a very slight shift of the measured values observed for the humidity sensor. In conclusion, NTP can be considered a gentle tool suitable for decontamination of various sensitive materials.

Inclusion of Biological Targets in the Analysis of Electrical Characteristics of Non-Thermal Plasma Discharge

In Plasma Medicine studies, the effect of non-thermal plasma (NTP) on biological targets is typically correlated with the amount of stable reactive oxygen and nitrogen species produced in a liquid medium. The effect of NTP and the response of the biological target on cellular redox mechanisms is overlooked in these investigations. Additionally, the influence of electrical properties of cells on the physical properties of NTP is neglected. Therefore, we used a floating electrode dielectric barrier discharge plasma to explore the impact of cell structure, size, and viability of the biological target on the physical properties of NTP. Lissajous figures were used to determine circuit capacitance and energy per cycle during NTP exposure of different cell suspensions. We show that both, structural integrity and active enzymic processes of cells change the electrical properties of NTP. Correlations were also drawn between NTP-produced hydrogen peroxide and nitrite with measured capacitance. Our studies indicate that the observed changes between different cell suspensions may be due to a feedback loop between the biological target and the NTP source. In future studies, a more detailed analysis is needed to improve the control of clinical NTP devices.

Comparing Non-Thermal Plasma and Cold Stratification: Which Pre-Sowing Treatment Benefits Wild Plant Emergence?

Meadow restoration and creation projects have faced a lack of local seed diversity due to the limited availability of seed sources. Non-thermal plasma technologies are being developed for agriculture and do not cause damage to heat-sensitive biological systems. This technology has shown the potential to improve agronomic seed quality by enhancing germination and promoting plant growth. However, there is almost no information about the effect of non-thermal plasma pretreatment on the seedlings' emergence of wild plant species. Therefore, this study aimed to evaluate the effect of non-thermal plasma on the emergence of 17 plant seeds originating from local meadows in Lithuania and compare it with the cold stratification pretreatment. The results obtained indicate that there were differences in emergence parameters among the species. However, NTP did not show statistically significant differences from the control. Non-thermal plasma improved the kinetic parameters of emergence for a few specific species' seeds, such as Anthyllis vulneraria and Prunella grandiflora, while the cold stratification pretreatment enhanced emergence for a broader range of plants. Significant differences were observed between non-thermal plasma and stratification pretreatment, as well as between the control and stratification groups. Both methods also had a negative impact.

Synergistic Effect of Nonthermal Plasma and ZnO Nanoparticles on Organic Dye Degradation

The synergetic effect of nonthermal plasma and ZnO nanoparticles (NPs) on the degradation efficiency of methylene blue was investigated. First, the ZnO nanoparticles were synthesized via the hydrothermal route; the spherical nanoparticles had diameters of 30–50 nm, as observed with a scanning electron microscope (SEM), and had hexagonal ZnO lattice structures, which was confirmed by both X-ray diffraction (XRD) and Raman spectroscopy. The X-ray-photoemission spectroscopy confirmed the ZnO composition and the presence of oxygen vacancies; meanwhile, the optical band gap energy was 3.17 eV. The optical emission of plasma radiation confirmed the presence of various active plasma species. Second, it was found that the maximum degradation efficiency of MB after 60 min was 85% in plasma alone and increased to 95% when combined with 0.2 gL−1 ZnO; but this decreased to 75% when ZnO loading increased to 0.4 gL−1. These results clearly show that combining plasma with the right amount of ZnO is a promising advanced oxidation technique as it provides an additional source of hydroxyl radicals and, at the same time, a source of photons that can excite the ZnO catalyst. The degradation mechanism for plasma alone and the plasma in combination with ZnO was presented.

P03-11: Prooxidative effect of non-thermal plasma generated from ambient air, nitrogen and oxygen on Schizosaccharomyces pombe

P03-11: Prooxidative effect of non-thermal plasma generated from ambient air, nitrogen and oxygen on Schizosaccharomyces pombe