Cold Atmospheric Pressure Plasma Research Articles

Interaction of Cold Atmospheric Pressure Plasma with Soybean Seeds: Effect on Germination and DNA, Seed Surface Characteristics and Plasma Diagnostics

This study investigates the relation between cold atmospheric pressure plasma (CAPP) effect on seeds and the plasma parameters. As a source of CAPP, the diffuse coplanar surface barrier discharge (DCSBD) generated in nitrogen, ambient air, and oxygen at atmospheric pressure was used. Results of germination and the level of DNA damage of soybean seeds (Glycine max L.) treated in plasma and plasma gaseous products showed that the most advantageous is the use of ambient air plasma treatment. The water contact angle (WCA) of samples treated directly in plasma was significantly smaller than that of samples treated with gaseous products. Using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), we did not observe significant changes between the spectra of individual samples, what indicates that there is no damage on the surface of the samples during the treatment, only the binding of polar groups. The method of optical emission spectroscopy (OES) and Fourier transform infrared spectroscopy (FTIR) were used to study the plasma parameters. The most radiant system observed in ambient air and nitrogen plasma is the second positive system of nitrogen N2C3∏u→B3∏g\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{N}}_{2} \\left( {{\ ext{C}}^{3} \\prod _{{\ ext{u}}} \ o {\ ext{B}}^{3} \\prod _{{\ ext{g}}} } \\right)$$\\end{document}. FTIR measurements showed the presence of reactive oxygen and nitrogen species O3, NO2, N2O, NO, HNO2 depending on the working gas. Finally, it can be assumed that the positive effect of plasma on the seed is caused not only by the individual components of the plasma, but also by their synergistic effect, while the ratio of the individual active particles as well as the plasma exposure to the seeds are important.

Stability of plasma improved adhesive property of polytetrafluoroethylene surface

In this study, the authors investigated the wettability change of atmospheric-pressure-cold-plasma (APCP)-treated polytetrafluoroethylene (PTFE) surfaces with time under different storage temperatures and pressures, and the results indicate that low temperature can hinder wettability recovery. After storage for 5 days, the water contact angle (WCA) of PTFE stored at room temperature (25°C) recovered from 19 ± 2 to 54 ± 2°, while the WCA of PTFE stored at low temperature (−10°C) increased to just 42 ± 3°. Then, the mechanism contributing to the slower wettability recovery was investigated by analyzing surface chemical compositions through X-ray photoelectron spectroscopy and observing surface morphologies using atomic force microscopy. After 15-day storage, the oxygen (O) and nitrogen (N) contents decreased obviously, while the fluorine (F) content increased. The fluorine content of the sample stored at low temperature was 20% less than that of the sample stored at room temperature. In contrast, surface micromorphologies were unchanged during storage, and the surface roughness R a of each sample was around 7 nm. Finally, peel strength tests were conducted on APCP-treated PTFE surfaces stored at different temperatures, and the surfaces stored at low temperature maintained better adhesive properties. After 15 days of storage, the adhesive strength could still reach 400 N/m, which was 376% higher than that of the untreated surface. The research results are expected to facilitate practical applications of APCP modification and PTFE surfaces significantly.

The cold atmospheric pressure plasma-generated species superoxide, singlet oxygen and atomic oxygen activate the molecular chaperone Hsp33.

Cold atmospheric pressure plasmas are used for surface decontamination or disinfection, e.g. in clinical settings. Protein aggregation has been shown to significantly contribute to the antibacterial mechanisms of plasma. To investigate the potential role of the redox-activated zinc-binding chaperone Hsp33 in preventing protein aggregation and thus mediating plasma resistance, we compared the plasma sensitivity of wild-type E. coli to that of an hslO deletion mutant lacking Hsp33 as well as an over-producing strain. Over-production of Hsp33 increased plasma survival rates above wild-type levels. Hsp33 was previously shown to be activated by plasma in vitro. For the PlasmaDerm source applied in dermatology, reversible activation of Hsp33 was confirmed. Thiol oxidation and Hsp33 unfolding, both crucial for Hsp33 activation, occurred during plasma treatment. After prolonged plasma exposure, however, unspecific protein oxidation was detected, the ability of Hsp33 to bind zinc ions was decreased without direct modifications of the zinc-binding motif, and the protein was inactivated. To identify chemical species of potential relevance for plasma-induced Hsp33 activation, reactive oxygen species were tested for their ability to activate Hsp33 in vitro. Superoxide, singlet oxygen and potentially atomic oxygen activate Hsp33, while no evidence was found for activation by ozone, peroxynitrite or hydroxyl radicals.

Modification of chia (Salvia hispanica L.) seed mucilage (a heteropolysaccharide) by atmospheric pressure cold plasma jet treatment

Chia seeds (CS) were subjected to atmospheric pressure cold plasma jet (APCPJ) for different times (30, 60, and 120 s) by using argon gas, and then chia mucilage (CM) was extracted from the seeds to investigate the technological properties of mucilage (a heteropolysaccharide). The gel samples prepared from dried CM obtained from CS treated with 30 s and 120 s APCPJ showed noticeably higher consistency index of 11.43 and 13.63 Pa.sn, while the control and 60 s APCPJ showed a lower consistency index of 1.07 and 0.35, respectively. Herschel-Bulkley was better at defining the flow behavior of CM gels, and the treatment increased the shear-thinning and consistency properties. Moreover, CM gels of APCPJ-treated seeds (30 s and 120 s) showed higher elastic properties and better resistance against deformation. The treatment induced cross-linking between polysaccharide chains as confirmed by FTIR, and SEM micrographs demonstrated that APCPJ caused etching on the surface of seeds, thus a more compact structure was obtained in the hydrated mucilage samples depending on the APCPJ time. The highest treatment time (120 s) decreased the solubility, and the water (15%) and oil holding capacity (25%), while it did not significantly affect the emulsion ability and stability. In conclusion, it was found that the APCPJ improved the viscosity and elastic features of CM gels by cross-linking and strengthening the polymer network, which may provide opportunities to use this gum in new food applications.

Efficacy Comparison of Three Atmospheric Pressure Plasma Sources for Soybean Seed Treatment: Plasma Characteristics, Seed Properties, Germination

Plasma seed treatment has proven to be a useful technique for improving germination, growth dynamics, as well as plant resistance. In this paper, we studied the efficacy of soybean seeds treatment using various sources of cold atmospheric pressure plasma generated in air. We compared three types of plasma treatments: direct treatment with plasma generated by a diffuse coplanar surface barrier discharge (DCSBD), direct treatment with plasma generated by a multi-hollow surface dielectric barrier discharge, and indirect treatment using the gaseous products of plasma generated by an air plasma jet. The composition of plasma generated by each of the sources was analysed using optical emission spectroscopy and Fourier Transform Infrared spectroscopy (FTIR). Parameters of the plasma treatments have been optimized to improve soybean germination. Plasma-treated seeds were examined by the means of water contact angle, surface free energy and imbibition measurements, attenuated total reflectance FTIR (ATR-FTIR), x-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) analyses. Surface analysis by ATR-FTIR and XPS showed changes in the chemical bonds on the surface of the plasma-treated seeds, which led to an increase in wettability and imbibition. SEM analysis confirmed that the plasma treatment is non-invasive and does not cause changes in seed surface morphology. Among the studied sources, DCSBD proved to be the best suited for soybean seed treatment in terms of germination improvement as well as treatment time and energy efficiency.

Changes in Flavor and Volatile Composition of Meat and Meat Products Observed after Exposure to Atmospheric Pressure Cold Plasma (ACP).

Studies on the atmospheric pressure cold plasma (ACP) exposure of meat and meat products mainly determine microbial inactivation, lipid oxidation, and meat color. Some studies include sensory evaluation, but only a few determine the changes in volatile composition due to ACP treatment. The results of sensory evaluation are inconclusive and range from "improvement" to "off-odor". This could be due to differences in the food matrix, especially in processed foods, or different experimental settings, including inadvertent effects such as sample heating. The few studies analyzing volatile composition report changes in alcohols, esters, aldehydes, and other compounds, but not necessarily changes that are novel for meat and meat products. Most studies do not actually measure the formation of reactive species, although this is needed to determine the exact reactions taking place in the meat during ACP treatment. This is a prerequisite for an adjustment of the plasma conditions to achieve antimicrobial effects without compromising sensory quality. Likewise, such knowledge is necessary to clarify if ACP-exposed meat and products thereof require regulatory approval.

Molecular dynamics simulation of the transmembrane transport process of reactive species under the synergistic effect of plasma oxidation and an electric field

Cold atmospheric pressure plasma (CAP)-assisted cancer therapy has become a popular topic in plasma biomedical research. Membrane lipid oxidation and local electric fields are two important factors in plasma–cell interactions, and the study of their synergistic effect is highly significant for optimizing the regulatory mechanism of the plasma-induced apoptosis of cancer cells. In this paper, a model of oxidized phospholipids was established, and the transmembrane process of reactive species was simulated by the classical molecular dynamics (MD) method under the conditions of oxidation and an electric field. The results showed that hydrophilic reactive oxygen species could not penetrate the membrane lipids through oxidation. The formation of electroporation provided a new channel for reactive species to penetrate the membrane, and the oxidation effect reduced the electric field threshold of membrane electroporation. Our simulation could provide theoretical support for the plasma-induced apoptosis of cancer cells at the microscopic level, provide mechanistic guidance for the practical application of plasma-induced cancer therapy, and promote the development of CAP in the field of cancer therapy.

Effect of cold atmospheric pressure plasma pretreatment on the drying kinetics, physicochemical properties and selected bioactive compounds of okra pods subjected to hot air impingement drying

This study aimed to evaluate the effect of cold atmospheric pressure plasma pretreatment (CP) on the drying kinetics, physicochemical properties, content of chlorophylls (alpha and beta), lycopene, phenolic compounds and antioxidant capacity of hot air impingement dried (HAID) okra pods. CP treatment significantly increased moisture diffusivity from 3.04 x 10−9 to 5.07 x 10−9 m2/s and decreased the HAID time by 38%, i.e., from 235 to 145 min. CP resulted in a reduction of alpha chlorophyll and lycopene contents, whereas the combination of CP and HAID allowed both chlorophylls to be preserved. The HPLC-MS/MS analysis revealed that CP-treated samples showed lower content of phenolic compounds, while combination of CP for 15 s and HAID provided excellent preservation of these compounds. The results show that the combination of the advanced CP treatment and HAID method was useful to obtain optimal results for both drying kinetics and the quality of okra pods.

Cold Atmospheric Pressure Plasma Jet and Plasma Lamp Interaction with Plants: Electrostimulation, Reactive Oxygen and Nitrogen Species, and Side Effects

Cold atmospheric pressure plasma (CAPP) treatment is a highly effective method of protecting seeds, plants, flowers, and trees from diseases and infection and significantly increasing crop yields. Here we found that cold atmospheric pressure He-plasma jet (CAPPJ) can also cause side effects and damage to plants if the plasma exposure time is too long. Reactive oxygen and nitrogen species (RONS), electromagnetic fields, and ultraviolet photons emitted by CAPPJ can cause both positive and negative effects on plants. CAPPJ can interact with biological tissue surfaces. The plasma lamp has no visible side effects on Aloe vera plants, cabbage, and tomatoes. A plasma lamp and a cold atmospheric pressure plasma He-jet cause strong electrical signaling in plants with a very high amplitude with frequencies equal to the frequency of plasma generation. The use of plasma lamps for electrostimulation of biological tissues can help to avoid side processes in biological tissues associated with the generation of RONS, UV photons, and direct interaction with cold plasma. CAPP technology can play an important role in agriculture, medicine, the food industry, chemistry, surface science, material science, and engineering applications without side effects if the plasma exposure is short enough.

An application of dielectric barrier discharge treatment to control gray mold growth on cut rose flowers

Cold atmospheric pressure plasma irradiation is an efficient method for decontaminating fruits and vegetables. The present study evaluates the effect of dielectric barrier discharge (DBD) cold plasma treatment on controlling gray mold (Botrytis cinerea Pers.), a destructive pathogen of cut roses (Rosa hybrida L. cv. Samurai). The ion leakage, relative water content (RWC), proline, chlorophyll, carotenoid, anthocyanin content, and discoloration of treated rose petals were measured. Experimental observation showed significant changes in ion leakage, RWC, and chlorophyll content at 20 kV for 8 min compared to the control. The same treatment induced significant changes in the proline content of the rose petals, but no statistical difference was observed in their anthocyanin and carotenoid contents compared to the control. The results indicated that gray mold growth was entirely suppressed by plasma irradiation at 20 kV for 4, 6, and 8 min and 15 kV for 8 min. Plasma at 10 kV for 8 min and 15 kV for 6 min suppressed 90% and 70% of the gray mold growth, respectively. It is noteworthy that plasma irradiation at 20 kV for just 4 min and at 15 kV for 6 min suppressed 100 and 70% of B. cinerea growth, respectively; however, plasma irradiation did not change the quality indices of rose petals. Overall, it can be said that cold plasma treatment by DBD has the potential to increase the shelf life of cut roses by suppressing gray mold development.

Cold atmospheric pressure plasma: A potential physical therapy for rheumatoid arthritis hyperplastic synovium

The most significant pathological change in rheumatoid arthritis (RA) is synovial hyperplasia within the joint. The production of a series of degrading enzymes and oxidative stress caused by synovial hyperplasia lead to severe bone and cartilage damage in rheumatoid joints. The core effector cell in hyperplastic synovium is fibroblast-like synovium cells, which can invade cartilage, cause inflammation, destroy joints, and show tumor-like anti-apoptosis characteristics. This study focused on the effect of cold atmospheric pressure plasma on proliferative synovium, and the results showed that no synovial hyperplasia, angiogenesis, or inflammatory infiltration was observed after cold atmospheric pressure plasma (CAP) treatment. The molecular and cellular mechanisms also reveal the spontaneous reactive oxygen species (ROS) cascade inducing apoptosis in rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) cells. This study proposes a potential physical therapy method for treating proliferative synovium and also provides ideas for the application of CAP in other types of tumor diseases.

Modification of Silicon Nanostructures by Cold Atmospheric Pressure Plasma Jets

Cold atmospheric plasma (CAP) jets with helium (He) and argon (Ar) plasma-forming gases were used to modify the structure, photoluminescence (PL), and electrical properties of arrays of silicon nanowires (SiNWs) with initial cross-section sizes of the order of 100 nm and length of about 7‒8 microns. The CAP source consisted of a 30 kHz voltage generator with a full power up to 5 W and the CAP treatment for 1‒5 min resulted in spattering of SiNWs’ tips followed by redeposition of silicon atoms. An increase of the silicon oxide phase and a decrease of the PL intensity were observed in the plasma processed SiNW arrays. A decrease of the free hole concentration and an increase in the free electron density were revealed in heavily boron and phosphorous doped SiNWs, respectively, as it was monitored by means of the Raman spectroscopy, considering a coupling of the light scattering by phonon and free charge carriers (Fano effect) in SiNWs. The obtained results demonstrate that the CAP treatment can be used to change the length, sharpness, luminescence intensity, and electrical properties of silicon nanowires for possible applications in optoelectronics and sensorics.

The localised density of H2O2 in the effluent of a cold atmospheric pressure plasma jet determined by continuous-wave cavity ring-down spectroscopy

Although the research on cold atmospheric pressure plasma jets and their applications is steadily growing, several questions remain open regarding fundamental aspects of how reactive species, such as hydrogen peroxide (H2O2), are generated in cold atmospheric pressure plasma jets, and how the composition of reactive species can be tailored for a specific purpose. Accordingly, absolute and spatially resolved distributions of the densities of reactive species in the effluent of cold atmospheric pressure plasma jets are required. In this work, a time efficient way to determine the local distribution of gas phase H2O2 in the effluent of a cold atmospheric-pressure plasma jet using continuous-wave cavity ring-down spectroscopy at a wavelength of 8.12 μm is presented. By a combination of an axial scan and of several radial distributions, the localised density distribution of H2O2 in the effluent of the kINPen-sci plasma jet was obtained. Therefore, the effective absorption length was determined from the evolution of the radial distributions as a function of the distance from the nozzle, which was 1.6 mm close to the nozzle of the plasma jet, and increased to approximately 5 mm at a distance of 10 mm from the nozzle. The maximum density of approximately 2 ⋅ 1014 cm−3 was found in the centre of the effluent close to the nozzle. From the presented localised density distribution, it can be concluded that H2O2 is significantly generated within the plasma zone of the plasma jet. This work presents an important step towards the understanding of formation and consumption mechanisms of biomedically relevant species in the plasma zone and the effluent of a cold atmospheric pressure plasma jet.

Influence of cold atmospheric pressure plasma treatment of Spirulina platensis slurry over biomass characteristics

Cold atmospheric pressure plasma (CAPP) technique is an innovative non-thermal approach for food preservation and decontamination. This study aimed to evaluate the effect of CAPP power density on microorganism inactivation and quality of Spirulina platensis (S. platensis) slurry. 91.31 ± 1.61% of microorganism were inactivated within 2.02 ± 0.11 min by 26.67 W/g CAPP treatment under 50 ℃. Total phenolic, Chlorophyll-a (Chl-a), and carotenoids contents were increased by 20.51%, 63.55%, and 70.04% after 20.00 W/g CAPP treatment. Phycobiliproteins (PBPs), protein, intracellular polysaccharide, and moisture content of S. platensis was decreased, while vividness, lightness, color of yellow and green, antioxidant activity, Essential Amino Acid Index were enhanced after CAPP treatment. The nutrient release and filaments breakage of CAPP-treated S. platensis improved its bio-accessibility. The findings provided a deep understanding and insight into the influence of CAPP treatment on S. platensis, which were meaningful for optimizing its sterilization and drying processing condition.

Investigating the characteristics of 11 kHz excitation of EFCAP and its selective effect on breast cancer cell death

AbstractRecently developed excitation frequency‐controlled cold atmospheric pressure plasma has shown its efficacy in producing tunable effects with different excitation frequencies in terms of reactive species generation and cancer cell death. This study investigates the electron number density of plasma produced at 11 kHz excitation from stark broadened Hα line, discharge characteristics through simultaneous recording of voltage‐current signals, and high‐speed images of the discharge zone. Malignant breast cancer cells (MCF‐7) and nonmalignant breast cells (MCF‐10A) were used in selectivity experiments. Proliferation and clonogenic assays revealed selective death of cancer cells. DNA damage and DNA repair kinetics were studied using time‐dependent γ‐H2AX foci formation assessment and the selective killing of cancerous cells was established for the 60 s of plasma treatment.

Achieving improved efficiency for removal of aflatoxin B1 by combination use of cold atmospheric-pressure plasma and plasma-activated water

A novel approach was employed to remove aflatoxin B1 (AFB1), a very toxic metabolite from Aspergillus flavus (A. flavus), by using cold atmospheric-pressure plasma (CAP) and plasma-activated water (PAW) in combination. The results showed that CAP could efficiently degrade AFB1, while the PAW produced by CAP could further remove AFB1 with a relatively long treatment time. During the CAP processing, hydroxyl radical (·OH) was one of the dominant reactive species, which caused the hydroxylation at furan ring of AFB1, while in PAW treatment, singlet oxygen (1O2) was the major reactive agent for AFB1 degradation, which caused the destruction of the methyl group on the benzene side chain and oxidized the double bond of the terminal furan ring in the AFB1 molecule. This study therefore provides new guidance for the application of plasma technology in the treatment of fungal mycotoxins for food safety.

Spatio-temporal species kinetics, thermal and electrical field evolution in an argon EFCAP under different rates of nitrogen seeding: A one-dimensional simulation study

Nitrogen seeding is crucial in cold plasma devices for production of reactive nitrogen species. Excitation Frequency Controlled Cold Atmospheric Pressure Plasma (EFCAP) devices belong to recent concepts in cold plasma where discharge kinetics can be controlled via tuning of external field frequency. The study presents time dependent modelling of such an atmospheric pressure non-DBD argon discharge between two bare electrodes in one dimension under different rates on nitrogen seeding using commercial software COMSOL Multiphysics version 5.4. A square alternating high voltage power source of frequency 11 kHz and peak voltage of 500V drives the discharge in the model. In every half-period, there is an electrical breakdown. Spatio-temporal variations in the electron density, ion density, electric field, electric potential, and electron temperature are investigated. Observed unique spatial oscillations in the species densities, species temperature and distinct drift in the observed characteristics with different rates of nitrogen seeding are some of the appealing aspects revealed by the study. The excitation and dissociation of molecules, generation and losses of ions, plasma mediated reactions and collisional excitations are accounted elaborately in the model developed. The study could explain the origin of typical non-uniform discharge patterns reported experimentally under different excitation frequencies in EFCAP. Obtained results are expected to be useful for better understanding of device physics towards development of improved cold plasma sources with desired characteristics.

Assessment of Cold Atmospheric Pressure Plasma (CAPP) Treatment for Degradation of Antibiotic Residues in Water.

The presence of antibiotic residues in water is linked to the emergence of antibiotic resistance globally and necessitates novel decontamination strategies to minimize antibiotic residue exposure in both the environment and food. A holistic assessment of cold atmospheric pressure plasma technology (CAPP) for β-lactam antibiotic residue removal is described in this study. CAPP operating parameters including plasma jet voltage, gas composition and treatment time were optimized, with highest β-lactam degradation efficiencies obtained for a helium jet operated at 6 kV. Main by-products detected indicate pH-driven peroxidation as a main mechanism of CAPP-induced decomposition of β-lactams. No in vitro hepatocytotoxicity was observed in HepG2 cells following exposure to treated samples, and E. coli exposed to CAPP-degraded β-lactams did not exhibit resistance development. In surface water, over 50% decrease in antibiotic levels was achieved after only 5 min of treatment. However, high dependence of treatment efficiency on residue concentration, pH and presence of polar macromolecules was observed.

Quantitative characterization of the temporal-spatial evolution of RONS in air surface micro-discharge using UV–VIS optical absorption spectroscopic diagnosis and modeling approach

The research of the chemically active species of cold atmospheric pressure plasmas is a essential step for a more in-depth comprehension of the effects of its interaction with the target. In this paper, the temporal and spatial evolution of key species O3, NO2 and NO3 produced by surface micro-discharge in air were investigated. UV–VIS optical absorption spectroscopy at 254 nm, 400 nm and 662 nm were used to measure the concentrations of O3, NO2 and NO3, respectively. The results show that the temporal evolution of O3, NO2 and NO3 are revealed a significant correlation with the surface power density (SPD). The phenomenon of O3 and NO3 quenching occur once the SPD overcomes a critical value of 0.15 W cm−2. An O3-enriched atmosphere (peak concentration around 3000 ppm) is formed when the SPD is below the critical value, and a NO2-enriched atmosphere (maximum NO2 density around 600 ppm) is formed at higher SPD. In addition, the concentration distribution of O3, NO2 and NO3 in the chamber ranging from 10–100 mm of the downstream of the mesh electrode tends to be uniform. Finally, a zero-dimensional model of the afterglow chemistry, validated using the experimental measurements, is developed to determined important reactions affecting O3, NO2 and NO3 respectively, and obtain insight into the evolutionary behavior of the considered reactive species.

Antimicrobial activity of cold atmospheric-pressure argon plasma combined with chicory (Cichorium intybus L.) extract against P. aeruginosa and E. coli biofilms

The present study reports a significant combined antibacterial activity of Cichorium intybus L. (known as Chicory) natural extract with cold atmospheric-pressure argon plasma treatment against multi-drug resistant (MDR) Gram-negative bacteria. To detect reactive species that are generated in the argon plasma, optical emission spectra were recorded. The molecular bands were allocated to the hydroxyl radicals (OH) and neutral nitrogen molecules (N2). Moreover, the atomic lines form the emitted spectra were determined to argon atoms (Ar) and the oxygen atoms (O), respectively. The results revealed that Chicory extract treatment at a concentration of 0.043 g/ml reduced the metabolic activity of P. aeruginosa cells by 42%, while, a reduced metabolic activity of 50.6% was found for E. coli biofilms. Moreover, the combination of Chicory extract with 3 min Ar-plasma introduced a synergistic effect, so that it exhibited a significantly reduced metabolic activity of P. aeruginosa to 84.1%, and E. coli ones to 86.7%, respectively. The relationship between cell viability and membrane integrity of P. aeruginosa and E. coli biofilms treated with Chicory extract and argon plasma jet were also analyzed by CLSM. It was found that after the combined treatment, a noticeable membrane disruption was formed. Besides, it was concluded that E. coli biofilms showed a higher sensitivity to Ar-plasma than P. aeruginosa biofilm at longer plasma exposure times. This study suggests that the anti-biofilm therapy based on a combined effect of Chicory extract and cold argon plasma treatment can serve as a considerable green method for treatment of antimicrobial MDR bacteria.