Floating Electrode Dielectric Barrier Discharge Research Articles

Synergistic Effects of Combined Flavourzyme and Floating Electrode-Dielectric Barrier Discharge Plasma on Reduction of Escherichia coli Biofilms in Squid (Todarodes pacificus).

This study investigated the synergistic effect of combining flavourzyme, a natural enzyme, and floating electrode-dielectric barrier discharge (FE-DBD) plasma (1.1 kV, 43 kHz, N2 1.5 m/s) treatment, a non-thermal decontamination technology, against Escherichia coli biofilms in squid. E. coli (ATCC 35150 and ATCC 14301) biofilms were formed on the surface of squid and treated with different minimum inhibitory concentrations (MICs) of flavourzyme (1/8; 31.25 μL/mL, 1/4; 62.5 μL/mL, 2/4; 125 μL/mL, and 3/4 MIC; 250 μL/mL) and FE-DBD plasma (5, 10, 30, and 60 min). Independently, flavourzyme and FE-DBD plasma treatment decreased by 0.26-1.71 and 0.19-1.03 log CFU/cm2, respectively. The most effective synergistic combination against E. coli biofilms was observed at 3/4 MIC flavourzyme + 60 min FE-DBD plasma exposure, resulting in a reduction of 1.55 log CFU/cm2. Furthermore, the combined treatment exhibited higher efficacy in E. coli biofilm inactivation in squid compared to individual treatments. The pH values of the synergistic combinations were not significantly different from those of the untreated samples. The outcomes indicate that the combined treatment with flavourzyme and FE-DBD plasma can effectively provide effective control of E. coli biofilms without causing pH changes in squid. Therefore, our study suggests a new microbial control method for microbial safety in the seafood industry.

The Efficacy of Floating Electrode-Dielectric Barrier Discharge Plasma against Staphylococcus aureus and Salmonella Typhimurium on Fried Fish Paste

In this study, we evaluated the antibacterial effect of floating electrode–dielectric barrier discharge (FE-DBD) plasma (1.1 kV, 43 kHz, N2 1.5 m/s, 1–60 min) against Staphylococcus aureus and Salmonella Typhimurium in fried fish paste. In addition, a quality evaluation (pH, VBN) of fried fish paste was conducted after the FE-DBD plasma treatment. When FE-DBD plasma was used for treatment for 1, 5, 10, 20, 30, and 60 min, S. aureus decreased by 0.16–1.13 log10 CFU/g, and S. Typhimurium decreased by 0.25–1.13 log10 CFU/g. Both decreased > log10 CFU/g at 60 min. The D-value was 58.92, and R2 was 0.97 for S. aureus using first-order kinetics, and the D-value was 43.60, and R2 was 0.97 for S. Typhimurium using the Weibull model. There was no significant difference in pH after the FE-DBD plasma treatment (p > 0.05). Additionally, volatile basic nitrogen (VBN) significantly decreased as the treatment time increased (p < 0.05), and it was the lowest 3.46 at 60 min. Therefore, this FE-DBD plasma treatment could be considered a technology for preserving the quality of processed foods.

Floating electrode-dielectric barrier discharge-based plasma promotes skin regeneration in a full-thickness skin defect mouse model.

Wound healing involves a complex and dynamic interplay among various cell types, cytokines, and growth factors. Macrophages and transforming growth factor-β1 (TGF-β1) play an essential role in different phases of wound healing. Cold atmospheric plasma has a wide range of applications in the treatment of chronic wounds. Hence, we aimed to investigate the safety and efficacy of a custom-made plasma device in a full-thickness skin defect mouse model. Here, we investigated the wound tissue on days 6 and 12 using histology, qPCR, and western blotting. During the inflammation phase of wound repair, macrophages play an important role in the onset and resolution of inflammation, showing decreased F4/80 on day 6 of plasma treatment and increased TGF-β1 levels. The plasma-treated group showed better epidermal epithelialization, dermal fibrosis, collagen maturation, and reduced inflammation than the control group. Our findings revealed that floating electrode-dielectric barrier discharge (FE-DBD)-based atmospheric-pressure plasma promoted significantly faster wound healing in the plasma-treated group than that in the control group with untreated wounds. Hence, plasma treatment accelerated wound healing processes without noticeable side effects and suppressed pro-inflammatory genes, suggesting that FE-DBD-based plasma could be a potential therapeutic option for treating various wounds.

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.

Inactivation of Human Norovirus GII.4 and Vibrio parahaemolyticus in the Sea Squirt (Halocynthia roretzi) by Floating Electrode-Dielectric Barrier Discharge Plasma.

Human norovirus (HNoV) GII.4 and Vibrio parahaemolyticus may be found in sea squirts. Antimicrobial effects of floating electrode-dielectric barrier discharge (FE-DBD) plasma (5-75 min, N2 1.5 m/s, 1.1 kV, 43 kHz) treatment were examined. HNoV GII.4 decreased by 0.11-1.29 log copy/μL with increasing duration of treatment time, and further by 0.34 log copy/μL when propidium monoazide (PMA) treatment was added to distinguish infectious viruses. The decimal reduction time (D1) of non-PMA and PMA-treated HNoV GII.4 by first-order kinetics were 61.7 (R2 = 0.97) and 58.8 (R2 = 0.92) min, respectively. V. parahaemolyticus decreased by 0.16-1.5 log CFU/g as treatment duration increased. The D1 for V. parahaemolyticus by first-order kinetics was 65.36 (R2 = 0.90) min. Volatile basic nitrogen showed no significant difference from the control until 15 min of FE-DBD plasma treatment, increasing after 30 min. The pH did not differ significantly from the control by 45-60 min, and Hunter color in "L" (lightness), "a" (redness), and "b" (yellowness) values reduced significantly as treatment duration increased. Textures appeared to be individual differences but were not changed by treatment. Therefore, this study suggests that FE-DBD plasma has the potential to serve as a new antimicrobial to foster safer consumption of raw sea squirts.

Simulation of Cold Atmospheric Plasma Generated by Floating-Electrode Dielectric Barrier Pulsed Discharge Used for the Cancer Cell Necrosis

A numerical simulation of a pulsed floating electrode dielectric barrier discharge (FE-DBD) at atmospheric pressure, used for melanoma cancer cell therapy, is performed using a plasma model in COMSOL Multiphysics software. Distributions of electron density, space charge, and electric field are presented at different instants of the pulsed argon discharge. Significant results related to the characteristics of the plasma device used, the inter-electrodes distance, and the power supply are obtained to improve the efficiency of FE-DBD apparatus for melanoma cancer cell treatment. The FE-DBD presents a higher sensitivity to short pulse durations, related to the accumulated charge over the dielectric barrier around the powered electrode. At higher applied voltage, more energy is injected into the discharge channel and an increase in electron density and electric consumed power is noted. Anticancer activity provided by the FE-DBD plasma is improved using a small interelectrode distance with a high electron emission coefficient and a high dielectric constant with a small dielectric thickness, allowing higher electron density, generating reactive species responsible for the apoptosis of tumor cells.

Effect of Cold Plasma on the Levels Mineral Blood Components <i>In Vivo</i>

This study illustrates effect of cold plasma CAP on the mineral blood components in vivo. the mineral blood component (Ca, Na, Cl, K and Fe) are used. Floating Electrode-Dielectric Barrier Discharge (FE-DBD) system of probe diameter 4cm is used for this purpose, and variable voltage (0-20) kV and variable frequency (0-30) kHz, the output power was ranged from (10 - 70) W. the effect of cold atmospheric plasma on mineral blood is studied with different exposure durations (30,45,60) sec. As the plasma exposure duration increases, the calcium, potassium and iron components in the blood increased, while The sodium and chlorine elements decreased. These results give an indication of the cold plasma receptor to be used to treat many diseases related to mineral blood components.

Development of a battery-operated floating-electrode dielectric barrier discharge plasma device and its characteristics

In this work, a portable floating-electrode dielectric barrier discharge (FE-DBD) device is designed with a rechargeable battery as the power supply. The characteristics of the FE-DBD with a metal electrode and human hand are studied and compared. The human contact safety is verified by calculating the current through the human body based on the equivalent circuit model. Escherichia coli inactivation experiments confirm the efficacy of the FE-DBD device in the envisaged applications.

Assessment of potential infectivity of human norovirus in the traditional Korean salted clam product “Jogaejeotgal” by floating electrode-dielectric barrier discharge plasma

This study investigated the antiviral effects of floating electrode-dielectric barrier discharge (FE-DBD) plasma treatment (1.1 kV, 43 kHz, N2 1.5 m/s, 5–30 min) against human norovirus (HuNoV) GII.4 in Jogaejeotgal Infectivity was assessed using real-time quantitative-PCR (RT-qPCR) following treatment of samples with propidium monoazide (PMA) and sodium lauroyl sarcosinate (Sarkosyl). This study also investigated the effects of FE-DBD plasma treatment on Jogaejeotgal quality (assessed using pH value and Hunter colors). Following inoculation, the average titers of HuNoV GII.4 in Jogaejeotgal significantly (P < 0.05) decreased with increases in the FE-DBD plasma treatment time in both the non-PMA-treated and PMA + Sarkosyl-treated samples; in the non-PMA and PMA + Sarkosyl treated Jogaejeotgal, HuNoV GII.4 titers (log10 copy number/µL) were to: 3.16 and 2.95 (5 min), 2.90 and 2.48 (10 min), 2.82 and 2.40 (15 min), 2.58 and 2.26 (20 min), 2.48 and 2.06 (25 min), and 2.23 and 1.91 (30 min), respectively. The average titers of HuNoV demonstrated significant (P < 0.05) reductions of 0.35 log10 (55.3%) in PMA + Sarkosyl-treated samples compared with the non-PMA treated samples following exposure to 5–30 min of FE-DBD plasma. Reductions of >1-log for HuNoV in PMA + Sarkosyl- treated Jogaejeotgal required treatments of FE-DBD of 5–30 min. Using the first order kinetic model (R2 = 0.95), GII.4 decimal reduction time (D-value) resulting from FE-DBD plasma was 23.75 min. The pH and Hunter colors (“L”, “a”, and “b”) were not significantly different (P > 0.05) between the untreated and FE-DBD plasma-treated Jogaejeotgal. Based on these results, the PMA + Sarkosyl/RT-qPCR method could be assessing HuNoV viability following 5–30 min treatment of FE-DBD plasma. Furthermore, may be an optimal treatment for Jogaejeotgal without altering the food quality (color and pH).

Microbial Inactivation by Non-equilibrium Short-Pulsed Atmospheric Pressure Dielectric Barrier Discharge (Cold Plasma): Numerical and Experimental Studies

Microbial inactivation efficacy of plasma generated by a custom-made floating electrode dielectric barrier discharge (FE-DBD) or cold plasma at three different frequencies (1 kHz, 2 kHz, and 3.5 kHz) was experimentally evaluated for its inactivation of the pathogen surrogate Enterobacter aerogenes on a glass surface to obtain inactivation kinetics. COMSOL Multiphysics® was used to numerically simulate the amount and the distribution of reactive species within an FE-DBD system. Microbial inactivation kinetics was predicted using species concentrations and microbial inactivation rates from the literature and compared with experimental data. The results showed that the FE-DBD plasma treatment achieved a microbial reduction of 4.3 ± 0.5 log CFU/surface at 3.5 kHz, 5.1 ± 0.09 log CFU/surface at 2 kHz, and 5.1 ± 0.05 log CFU/surface at 1 kHz in 2 min, 3 min, and 6 min, respectively. The predicted values were 4.02 log CFU/surface, 4.10 log CFU/surface, and 4.56 log CFU/surface at 1 kHz, 2 kHz, and 3.5 kHz, respectively. A maximum 1 log difference was observed between numerical predictions and the experimental results. The difference might be due to synergistic interactions between plasma species, UV component of FE-DBD plasma, and/or the electrical field effects, which could not be included in the numerical simulation.

Breast cancer treatment using cold atmospheric plasma generated by the FE-DBD scheme

BackgroundCold atmospheric plasma (CAP) is widely used in the cancer therapy field. This type of plasma is very close to room temperature. This paper illustrates the effects of CAP on breast cancer tissues both in vivo and in vitro. MethodsThe mouse mammary adenocarcinoma cell line AN3 was used for the in vivo study, and the MCF7, AMJ13, AMN3, and HBL cell lines were used for the in vitro study. A floating electrode-dielectric barrier discharge (FE-DBD) system was used. The cold plasma produced by the device was tested against breast cancer cells. ResultsThe induced cytotoxicity percentages were 61.7%, 68% and 58.07% for the MCF7, AMN3, and AMJ13 cell lines, respectively, whereas the normal breast tissue HBL cell line exhibited very little or no cytotoxicity. Reactive oxygen species (ROS) were measured, and we found that more ROS were generated under the impact of CAP in cancer cells, whereas the normal HBL cell line had the lowest ROS level. The in vivo study showed that CAP treatment could reduce the volume of treated tumors compared to those in untreated mice. ConclusionsCAP has anticancer effects both in vitro and in vivo and this effect is mediated by the ROS and induce apoptosis in p53 independent pathway. the current method is promising for breast cancer therapy.

Enhanced Abrasion Resistance of Coated Particleboard Pre-Treated with Atmospheric Plasma

This study aims to investigate the influence of atmospheric plasma treatment on the abrasion resistance of particleboards, as an example of a wood-based material, coated with a waterborne finish. The treatment of the substrate, prior to coating application, using a floating-electrode dielectric barrier discharge (FE-DBD) plasma, resulted in an enhanced abrasion resistance of the coated particleboards in comparison to the untreated ones during the abrasion test with a duration of 200 revolutions. This finding was related to lower contact angles of water and coating after treatment with plasma and greater hardness of the coating on the treated substrates. The micrographs of the sample cross sections recorded with scanning electron microscope showed differences in the amounts of remained coating on the abraded areas. Investigation with attenuated total reflection Fourier transform infrared spectroscopy revealed that treatment of the substrate with plasma did not affect the chemical composition nor the curing and structure of the later applied coating. Further studies should be performed to determine the resistance properties of such surface systems to other impacts.

Effect of Cold Atmospheric Pressure Plasma on Fertility Hormones for Female Rats

The direct application of cold atmospheric plasma (CAP) is the main scope of plasma medicine in or on the organism for curative purposes. Cold plasma is both effective in disrupting a wide range of microorganisms including multiple drug resistant ones (MDRs) and to stimulate proliferation of mammalian cells. It has obtained by Floating Electrode Dielectric Barrier Discharge (FE-DBD) system. The present study aimed to show the effected of cold plasma on the fertility hormones LH, Prolactin, Estrogen, and Testosterone hormones for healthy adult female rats (Albino) / bulb c). There are divided into many groups according to time exposure of plasma (15, 30, 60, and 90 second) and a reference group (without plasma exposure), with different time intervals after exposure (1, 2, 3, 7, 14, 28 days). The concentration of hormones was measured using Enzyme Linked Immunosorbent Assay (ELISA). The results showed that, the CAP effected slightly on the Luteinizing Hormone (LH) and Estradiol Hormone (E2) the concentration levels slightly increased and stay near to the reference value for all times. Prolactin hormone (PRL) was effected significantly from the first day after exposure to CAP for all times, it was increased significantly (P < 0.0001) for short time of exposure (15, 30 sec) than control group value, and it was decreased significantly (P < 0.0001) than control value for time of exposure ( 60, 90 sec). The result of testosterone hormone is decreased significantly from the first day after exposure to CAP for all time exposure (15, 30, 60, and 90 sec).

Sanitary effect of FE-DBD cold plasma in ambient air on sewage biosolids

Sewage sludge is treated by means of cold plasma and stabilization in terms of biological load deactivation is achieved. The plasma is produced by floating electrode dielectric barrier discharge operating with air under atmospheric pressure conditions. The process is presented in detail and the discharge is characterized electrically. Additionally, simulation of the thermal flow inside the process chamber is implemented, using computational fluid dynamics. Deactivation of the serotypes S. Paratyphi B., S. Livingstone, S. Mbandaka and S. Typhimurium, and Escherichia coli and Coliforms, is hereby claimed. The process involves mean electrical power in the range of tens of watts, treatment time in the scale of minutes, and maximum instantaneous temperature <400 K. The present work is a preliminary contribution towards the promotion of advanced methods for the pro-ecological management of biosolids, according to European Regulations.

Plasma skincare device based on floating electrode dielectric barrier discharge

A portable skincare plasma-device with a rechargeable battery is presented here. The device comprises two pads made of thin polyimide film as the dielectric layer, namely, the dielectric barrier discharge pad (DBD-pad) for skin-touch and a capacitive ground-pad (G-pad) for hand holding. High AC voltage of approximately 1 kV with frequency of 40 kHz is induced in the DBD-pad that contacts the skin, which serves as the floating electrode, while low voltage is induced on the G-pad. Considering the requirement for impedance matching between the DBD-pad capacitance and the inverter along with the need for low skin current less than approximately 5 mA for electrical safety, the electrode area of the DBD-pad is minimized to be smaller than that of the G-pad.

Atmospheric-pressure floating electrode-dielectric barrier discharge with flexible electrodes: Effect of conductor shapes

The plasma characteristics of atmospheric-pressure floating electrode-dielectric barrier discharges (FE-DBDs), which comprised flexible electrodes and were able to generate a plasma along the curvature of skin, were investigated using Cu conductors with various shapes in the flexible powered electrode. These Cu conductors have similar areas but different contour lengths and the shapes of a square, a dumbbell, a star, and a zigzag pattern. The optical intensity and electron temperature of the atmospheric-pressure FE-DBDs increased with the contour length of the conductor used in the flexible powered electrode. This behavior is explained in terms of the changes in the strength of the electric field with the contour length of the conductor, implying that the plasma properties of atmospheric-pressure FE-DBDs with flexible electrodes can be controlled by modulating the contour length or the shape of the electrical conductor in the flexible powered electrode. These results are expected to contribute to the development of an atmospheric-pressure FE-DBD system for plasma medicine.

Artificially aged spruce and beech wood surfaces reactivated using FE-DBD atmospheric plasma

Abstract Although weathering is usually carried out in outdoor conditions, even ageing in indoor conditions can cause significant changes to wood surfaces. We found these to notably impact wetting and coatability of surfaces of common beech (Fagus sylvatica L.) and Norway spruce [Picea abies (L.) Karst.] wood. These effects were well overcome and the surfaces reactivated using a novel kind of a plasma device. On both kinds of wood, ageing caused significant changes in their colour, opening of pits and cell wall destruction. Infrared spectra indicated a significant decrease of aromatic lignin and production of non-conjugated carbonyl groups. Surface free energies and spreading kinetics varied much upon this kind of ageing. In beech, pull-off strengths for a commercial waterborne wood coating slightly decreased for longer exposure times. For the reactivation of wood surfaces, we employed a novel approach using a floating electrode dielectric barrier discharge (FE-DBD) plasma, which had not been done on wood before. Similar to other plasma techniques, the surface free energy (SFE) increased after treatment. On beech wood, the plasma treatment (PT) led to higher pull-off strengths of the waterborne coating. On spruce wood, the coating mostly showed cohesive failures after ageing, and thus the PTs showed less improvements.

Mechanism of Ampicillin Degradation by Non-Thermal Plasma Treatment with FE-DBD

This research focused on determining the effectiveness of non-thermal atmospheric pressure plasma as an alternative to advanced oxidation processes (AOP) for antibiotic removal in solution. For this study, 20 mM (6.988 g/L) solutions of ampicillin were treated with a floating electrode dielectric barrier discharge (FE-DBD) plasma for varying treatment times. The treated solutions were analyzed primarily using mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). The preliminary product formed was Ampicillin Sulfoxide, however, many more species are formed as plasma treatment time is increased. Ampicillin was completely eliminated after five minutes of air-plasma treatment. The primary mechanism of ampicillin degradation by plasma treatment is investigated in this study.

A Comparison of Floating-Electrode DBD and kINPen Jet: Plasma Parameters to Achieve Similar Growth Reduction in Colon Cancer Cells Under Standardized Conditions

A comparative study of two plasma sources (floating-electrode dielectric barrier discharge, DBD, Drexel University; atmospheric pressure argon plasma jet, kINPen, INP Greifswald) on cancer cell toxicity was performed. Cell culture protocols, cytotoxicity assays, and procedures for assessment of hydrogen peroxide (H2O2) were standardized between both labs. The inhibitory concentration 50 (IC50) and its corresponding H2O2 deposition was determined for both devices. For the DBD, IC50 and H2O2 generation were largely dependent on the total energy input but not pulsing frequency, treatment time, or total number of cells. DBD cytotoxicity could not be replicated by addition of H2O2 alone and was inhibited by larger amounts of liquid present during the treatment. Jet plasma toxicity depended on peroxide generation as well as total cell number and amount of liquid. Thus, the amount of liquid present during plasma treatment in vitro is key in attenuating short-lived species or other physical effects from plasmas. These in vitro results suggest a role of liquids in or on tissues during plasma treatment in a clinical setting. Additionally, we provide a platform for correlation between different plasma sources for a predefined cellular response.

Biomolecule Response to Nonthermal Plasma

This work demonstrated the decomposition products of several amino acids when exposed to nonthermal atmospheric pressure plasma. A floating electrode dielectric barrier discharge plasma was used to treat 20 mM solutions of cysteine, glutamine, alanine, and lysine for varying treatment times to investigate possible mechanisms in cell wall degradation and treatment of tissue. The treated solutions were analyzed primarily using gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR). The primary targets of the plasma treatment were found to be the sulfur or nitrogen species. Acetic acid and lactic acid were observed throughout all solutions as oxidative products from the plasma treatment. This work suggests that the primary targets for plasma treatment of cell wall components is the amino acids.