scholarly journals A map of control for cold atmospheric plasma jets: From physical mechanisms to optimizations

2021 ◽  
Vol 8 (1) ◽  
pp. 011306
Author(s):  
Li Lin ◽  
Michael Keidar
Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 249
Author(s):  
Zhitong Chen ◽  
Richard Obenchain ◽  
Richard E. Wirz

Conventional plasma jets for biomedical applications tend to have several drawbacks, such as high voltages, high gas delivery, large plasma probe volume, and the formation of discharge within the organ. Therefore, it is challenging to employ these jets inside a living organism’s body. Thus, we developed a single-electrode tiny plasma jet and evaluated its use for clinical biomedical applications. We investigated the effect of voltage input and flow rate on the jet length and studied the physical parameters of the plasma jet, including discharge voltage, average gas and subject temperature, and optical emissions via spectroscopy (OES). The interactions between the tiny plasma jet and five subjects (de-ionized (DI) water, metal, cardboard, pork belly, and pork muscle) were studied at distances of 10 mm and 15 mm from the jet nozzle. The results showed that the tiny plasma jet caused no damage or burning of tissues, and the ROS/RNS (reactive oxygen/nitrogen species) intensity increased when the distance was lowered from 15 mm to 10 mm. These initial observations establish the tiny plasma jet device as a potentially useful tool in clinical biomedical applications.


2006 ◽  
Vol 88 (17) ◽  
pp. 171501 ◽  
Author(s):  
J. L. Walsh ◽  
J. J. Shi ◽  
M. G. Kong

2009 ◽  
Vol 11 (3) ◽  
pp. 293-296 ◽  
Author(s):  
Tang Daotan ◽  
Ren Chunsheng ◽  
Wang Dezhen ◽  
Nie Qiuyue

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4396
Author(s):  
Kateřina Polášková ◽  
Miloš Klíma ◽  
Zdeňka Jeníková ◽  
Lucie Blahová ◽  
Lenka Zajíčková

Polypropylene is a typical representative of synthetic polymers that, for many applications including adhesive joints, requires an increase in wettability and chemical surface reactivity. Plasma processing offers efficient methods for such surface modifications. A particular disadvantage of the plasma jets can be the small plasma area. Here, we present a cold atmospheric plasma radio-frequency slit jet developed with a width of 150 mm applied to polypropylene plasma treatment in Ar, Ar/O2 and Ar/N2 We identified two main parameters influencing the tensile strength of adhesive joints mediated by epoxy adhesive DP 190, nitrogen content, and the amount of low molecular weight oxidized materials (LMWOMs). Nitrogen functional groups promoted adhesion between epoxy adhesive DP 190 and the PP by taking part in the curing process. LMWOMs formed a weak boundary layer, inhibiting adhesion by inducing a cohesive failure of the joint. A trade off between these two parameters determined the optimized conditions at which the strength of the adhesive joint increased 4.5 times. Higher adhesion strength was previously observed when using a translational plasma gliding arc plasma jet with higher plasma gas temperatures, resulting in better cross linking of polymer chains caused by local PP melting.


2010 ◽  
Vol 38 (11) ◽  
pp. 3156-3162 ◽  
Author(s):  
Nicolae Georgescu ◽  
Cristian P. Lungu ◽  
Andreea Roxana Lupu ◽  
Mariana Osiac

2018 ◽  
Vol 10 ◽  
pp. 175883591878647 ◽  
Author(s):  
Antoine Dubuc ◽  
Paul Monsarrat ◽  
François Virard ◽  
Nofel Merbahi ◽  
Jean-Philippe Sarrette ◽  
...  

Background: Cold-atmospheric plasma (CAP) is an ionized gas produced at an atmospheric pressure. The aim of this systematic review is to map the use of CAP in oncology and the implemented methodologies (cell targets, physical parameters, direct or indirect therapies). Methods: PubMed, the International Clinical Trials Registry Platform and Google Scholar were explored until 31 December 2017 for studies regarding the use of plasma treatment in oncology ( in vitro, in vivo, clinical trials). Results: 190 original articles were included. Plasma jets are the most-used production systems (72.1%). Helium alone was the most-used gas (35.8%), followed by air (26.3%) and argon (22.1%). Studies were mostly in vitro (94.7%) and concerned direct plasma treatments (84.2%). The most targeted cancer cell lines are human cell lines (87.4%), in particular, in brain cancer (16.3%). Conclusions: This study highlights the multiplicity of means of production and clinical applications of the CAP in oncology. While some devices may be used directly at the bedside, others open the way for the development of new pharmaceutical products that could be generated at an industrial scale. However, its clinical use strongly needs the development of standardized reliable protocols, to determine the more efficient type of plasma for each type of cancer, and its combination with conventional treatments.


2018 ◽  
Vol 18 (6) ◽  
pp. 784-804 ◽  
Author(s):  
Georg Bauer

Background: Application of cold atmospheric plasma to medium generates “plasma-activated medium” that induces apoptosis selectively in tumor cells and that has an antitumor effect in vivo. The underlying mechanisms are not well understood. Objective: Elucidation of potential chemical interactions within plasma-activated medium and of reactions of medium components with specific target structures of tumor cells should allow to define the active principle in plasma activated medium. Methods: Established knowledge of intercellular apoptosis-inducing reactive oxygen/nitrogen species-dependent signaling and its control by membrane-associated catalase and SOD was reviewed. Model experiments using extracellular singlet oxygen were analyzed with respect to catalase inactivation and their relevance for the antitumor action of cold atmospheric plasma. Potential interactions of this tumor cell-specific control system with components of plasma-activated medium or its reaction products were discussed within the scope of the reviewed signaling principles. Results: None of the long-lived species found in plasma-activated medium, such as nitrite and H2O2, nor OCl- or .NO seemed to have the potential to interfere with catalase-dependent control of apoptosis-inducing signaling of tumor cells when acting alone. However, the combination of H2O2 and nitrite might generate peroxynitrite. The protonation of peroxnitrite to peroxynitrous acid allows for the generation of hydroxyl radicals that react with H2O2, leading to the formation of hydroperoxide radicals. These allow for singlet oxygen generation and inactivation of membrane-associated catalase through an autoamplificatory mechanism, followed by intercellular apoptosis-inducing signaling. Conclusion: Nitrite and H2O2 in plasma-activated medium establish singlet oxygen-dependent interference selectively with the control system of tumor cells.


Sign in / Sign up

Export Citation Format

Share Document