Influence of air diffusion on the OH radicals and atomic O distribution in an atmospheric Ar (bio)plasma jet

Nikiforov, Anton; Li, L; Britun, Nikolay; Snyders, Rony; Vanraes, Patrick; Leys, Christophe

doi:10.1088/0963-0252/23/1/015015

Cited by 35 publications

(28 citation statements)

References 43 publications

(61 reference statements)

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“…It has been proposed that the plasma generated in Helium with O 2 and H 2 O is rich not only in O, O 2 *, and O 3 but also in OH and H 2 O 2 . [49][50][51][52] By utilizing different ROS scavengers, we found that H 2 O 2 played an important role in the cytotoxic effects on Bel7402 cells. H 2 O 2 is moderately reactive and is relatively long-lived molecules, 53 and it is also the only ROS that could diffuse over membrane with large distances within the cells.…”

Section: Discussionmentioning

confidence: 99%

Effects of atmospheric pressure cold plasma on human hepatocarcinoma cell and its 5-fluorouracil resistant cell line

et al. 2015

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Atmospheric pressure cold plasma showed selective killing efficiency on cancer cells in vitro and in vivo, which makes plasma a potential option for cancer therapy. However, the plasma effects on chemotherapeutic drugs-resistant cells are rarely to be found. In this paper, the effects of plasma on human hepatocellular carcinoma Bel7402 cells and 5-fluorouracil (5-FU) resistant Bel7402/5FU cells were intensively investigated. The results showed that plasma induced superior toxicity to Bel7402 cells compared with Bel7402/5FU cells. Incubation with plasma-treated medium for 20 s induced more than 85% death rate in Bel7402 cells, while the same death ratio was achieved when Bel7402/5FU cells were treated for as long as 300 s. The hydrogen peroxide in the medium played a leading role in the cytotoxicity effects. Further studies implicated that when the treatment time was shorter than 60 s, the depolarization of mitochondrial membrane potential and apoptosis occurred through the intracellular reactive oxygen species accumulation in Bel7402 cells. Molecular analysis showed an increase in the transcription factor activity for AP-1, NF-кB, and p53 in Bel7402 cells. No obvious damage could be detected in plasma-treated Bel7402/5FU cells due to the strong intracellular reactive oxygen stress scavenger system.

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Section: Discussionmentioning

confidence: 99%

Effects of atmospheric pressure cold plasma on human hepatocarcinoma cell and its 5-fluorouracil resistant cell line

et al. 2015

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“…When a plasma jet propagates in ambient air, the diffusion of the ambient air will affect the reactive species generation. There are two ways to control the diffusion of the ambient air [277][278][279][280][281][282]. One way is by placing the plasma jet inside a sealed container, which is filled with the desired gas.…”

Section: Effect Of Diffusion Of Shielding Gas On O Productionmentioning

confidence: 99%

Reactive species in non-equilibrium atmospheric-pressure plasmas: Generation, transport, and biological effects

et al. 2016

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Non-equilibrium atmospheric-pressure plasmas have recently become a topical area of research owing to their diverse applications in health care and medicine, environmental remediation and pollution control, materials processing, electrochemistry, nanotechnology and other fields. This review focuses on the reactive electrons and ionic, atomic, molecular, and radical species that are produced in these plasmas and then transported from the point of generation to the point of interaction with the material, medium, living cells or tissues being processed. The most important mechanisms of generation and transport of the key species in the plasmas of atmospheric-pressure plasma jets and other non-equilibrium atmosphericpressure plasmas are introduced and examined from the viewpoint of their applications in plasma hygiene and medicine and other relevant fields. Sophisticated high-precision, timeresolved plasma diagnostics approaches and techniques are presented and their applications to monitor the reactive species and plasma dynamics in the plasma jets and other discharges, both in the gas phase and during the plasma interaction with liquid media, are critically reviewed. The large amount of experimental data is supported by the theoretical models of reactive species generation and transport in the plasmas, surrounding gaseous environments, and plasma interaction with liquid media. These models are presented and their limitations are discussed. Special attention is paid to biological effects of the plasma-generated reactive oxygen and nitrogen (and some other) species in basic biological processes such as cell metabolism, proliferation, survival, etc. as well as plasma applications in bacterial inactivation, wound healing, cancer treatment and some others. Challenges and opportunities for theoretical and experimental research are discussed and the authors' vision for the emerging convergence trends across several disciplines and application domains are presented to stimulate critical discussions and collaborations in the future. 4 3.5 Optical absorption spectroscopy 3.5.1 Ozone 3.5.2 UV broadband absorption of OH density 3.5.3 Cavity ring-down spectroscopy 3.5 Selected non-optical techniques 3.5.1 Mass spectrometry 3.5.2 Flow visualization 3.5.3 Electron paramagnetic resonance spectroscopy 4. Temporal and spatial behaviour of key reactive species 4.1 Electron density (n e) 4.2 O atoms 4.2.1 Effect of admixture of O 2 /air on O concentration 4.2.2 Diffusion effect of shielding gas on O production 4.3 OH radical 4.3.1 Effect of H 2 O admixture on OH concentration 4.3.2 Effect of gas flow on OH concentration 4.3.3 Effect of O 2 on OH production 4.3.4 Effect of the treated samples on OH concentration 4.3.4.1 Effect of humidity of treatment sample on OH distribution 4.3.4.2 Effect of sample conductivity on OH distribution 4.3.4.3. Effect of the amplitude of the applied voltage on OH distribution 4.3.4.4. The effect of gas flow on OH distribution 4.3.4.5. The effect of the surface characteristics on OH distribution 4.3.5 Effe...

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“…The observed oxygen incorporation is due to the admixture of air in the plasma effluent. This leads to a higher yield of OH and O in the core of the discharge when the discharge is operating in ambient air [16]. Due to the recombination processes of OH and O with intrusions of nitrogen and oxygen molecules from the surrounding air, only a low amount of these species will reach the LDPE surface at higher distances, resulting into less hydrophilic surfaces and lower O/C ratios.…”

Section: Influence Of the Distance Between The Capillary And The Foilmentioning

confidence: 99%

Surface modification of polyethylene in an argon atmospheric pressure plasma jet

Deynse

Cools

Leys

et al. 2015

Surface and Coatings Technology

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The surface properties of polyethylene can successfully be altered using argon plasmas. In this work, the surface modification of low density polyethylene (LDPE) using an argon atmospheric pressure plasma jet (APPJ) is profoundly investigated. The surface modification is examined using different analysing techniques namely, water contact angle (WCA) measurements for the wettability and X-ray photoelectron spectroscopy (XPS) for the chemical composition. Particular attention is paid to the treatment distance between the plasma jet capillary and the LDPE foil and the applied treatment time. At treatment distances between 5 and 15 mm, the WCA can be reduced with more than 70% within a treatment time of a few ms. XPS measurements reveal that this is due to the incorporation of oxygen containing groups and especially the increased implementation of the O-C=O group has a big influence. At treatment distances above 15 mm, the wettability decreases with increasing treatment distance. The wettability can however be enhanced by increasing the treatment time. Ageing considerations show that the loss in treatment efficiency is restricted to only 25%, meaning that even after 14 days of ageing the WCA reduction upon plasma treatment is still more than 40%. Based on the above mentioned results, the most appropriate parameters can thus be selected to provide an efficient plasma treatment of LDPE using the argon APPJ.3

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Influence of air diffusion on the OH radicals and atomic O distribution in an atmospheric Ar (bio)plasma jet

Cited by 35 publications

References 43 publications

Effects of atmospheric pressure cold plasma on human hepatocarcinoma cell and its 5-fluorouracil resistant cell line

Effects of atmospheric pressure cold plasma on human hepatocarcinoma cell and its 5-fluorouracil resistant cell line

Reactive species in non-equilibrium atmospheric-pressure plasmas: Generation, transport, and biological effects

Surface modification of polyethylene in an argon atmospheric pressure plasma jet

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