Effect Of Low-temperature Plasma Research Articles

Effects of Low-Temperature Plasma Glow Discharge on the Proliferative Activity of Cells and the Repair Functions of Tissues in Animals and Plants

We present here the results of studies of the effect of low-temperature plasma on the proliferative activity of cells and the repair functions of the biological tissues in animals and plants. The influences of low-temperature plasma on the viability and proliferative activity of human stem cells are considered. Human stem cells can undergo apoptosis or proliferate, depending on the location of the zone of action and the observation time. Treatment of plants with the low-temperature plasma-activated drug Plazmolit, using dilutions giving a high concentration, was found to suppress growth and development, while low concentrations activated growth. These study results led to the conclusion that there is a single mechanism for the processes whereby low-temperature plasma affects the proliferative activity of cells and the repair functions of biological tissues in animals and plants.

Antibacterial effects of low-temperature plasma generated by atmospheric-pressure plasma jet are\xa0mediated by reactive oxygen species

Emergence and spread of antibiotic resistance calls for development of non-chemical treatment options for bacterial infections. Plasma medicine applies low-temperature plasma (LTP) physics to address biomedical problems such as wound healing and tumor suppression. LTP has also been used for surface disinfection. However, there is still much to be learned regarding the effectiveness of LTP on bacteria in suspension in liquids, and especially on porous surfaces. We investigated the efficacy of LTP treatments against bacteria using an atmospheric-pressure plasma jet and show that LTP treatments have the ability to inhibit both gram-positive (S. aureus) and gram-negative (E. coli) bacteria on solid and porous surfaces. Additionally, both direct LTP treatment and plasma-activated media were effective against the bacteria suspended in liquid culture. Our data indicate that reactive oxygen species are the key mediators of the bactericidal effects of LTP and hydrogen peroxide is necessary but not sufficient for antibacterial effects. In addition, our data suggests that bacteria exposed to LTP do not develop resistance to further treatment with LTP. These findings suggest that this novel atmospheric-pressure plasma jet could be used as a potential alternative to antibiotic treatments in vivo.

On the low-temperature plasma discharge in methane/air diffusion flames

Interest in methane has grown recently because of its encouraging characteristics. However, methane comes with serious concerns regarding stability and flammability limitations. Some methods have been proposed to improve the ignition characteristics of methane in diffusion flame burners such as electrical fields, dielectric barrier discharge, and low-temperature plasma. In this study, an innovative single-element coaxial shear injector coupled with a high-voltage nanosecond pulse generator has been used to study the effects of low-temperature plasma (LTP) discharge on methane/air inverse diffusion flame at different plasma and flow conditions. The stability analysis focuses on the detachment conditions of the flame and how RNP discharge can delay this phenomenon, explaining the presence of an optimal operating point with the least applied energy. Comparing the lean blow-off limits for the cases with and without plasma discharge, it is shown that low-temperature plasma discharge enhances the flammability of the diffusion flame. The effect of LTP discharge on laminar flames is also discussed using chemiluminescence photography. It shows that the shape of the diffusion flame becomes more similar to premixed flame with more air entrainment and stability. Resultantly, it is shown that RNP discharge can improve the flame stability and ignition characteristics.

Влияние низкотемпературной плазмы и γ-излучения на поверхностные свойства тонких пленок на основе полимолочной кислоты

Effects of the low-temperature plasma exposure, γ-irradiation, and joint g-irradiation and plasma exposure on the structure and surface properties of thin films based on polylactic acid (PLA) have been investigated. Films were obtained by the method a solvent-casting. It has been shown that films based on polylactic acid have topographically different sides: a smoother inner side and embossed outer one. PLA films have properties close to those hydrophobic, with a contact angle in the range of 70°-73° regardless of the surface side and belong to a weakly polar materials. The combined effect of plasma and gamma radiation slightly changes the surface topography. The effect of low-temperature plasma on the surface of the films leads to a decrease in the contact angle by 13°-55° (9-11%) and an increase in surface energy due to the polar component. The results of in vivo experiments on rabbits are presented. Biomicroscopy, optical coherence tomography, morphological and electron microscopic examination of the cornea after implantation of initial and radiation and plasma treated films showed that implantation of the films in the anterior chamber is not accompanied by a pronounced inflammatory reaction and increased intraocular pressure, while maintaining the morphological structure of the cornea almost unchanged.

Modified sorbents based on diatomites

Introduction: the quality of the air environment in the premises depends mainly on the presence of toxic chemical substances in it. An urgent task is the development and application of new efficient building materials using aggregates with high sorption capacity. The paper presents the results of a study of the influence of a low-temperature nonequilibrium plasma on the sorption characteristics of diatomite-based aggregates.
 Materials and methods: the diatomites of the Irbit deposit, quartz sand were chosen as the materials under study. The study of the effect of low-temperature plasma on the change in the characteristics of modified diatomites was performed using the Raman spectrometer Senterra. The change in the sorption characteristics of diatomites was determined by the gravimetric method.
 Results: plasma-modified prototypes of a diatomite-based sorbent, with higher sorption characteristics than the initial ones, were obtained. Analysis of the results obtained by the method of Raman scattering confirmed the structural change on the surface of plasma-modified samples with the formation of additional active centers and radicals.
 Conclusions: modified sorbents are able to provide more efficient absorption of toxic substances in comparison with the control samples. After additional technological research, they can be recommended for introduction into the production of building materials with additional properties to ensure the regulatory requirements for the quality of the air environment in the premises.

Effect of low temperature plasma of atmospheric pressure on single-cell model organisms of ciliate Paramecium caudatum

We studied low-temperature plasma effects on Paramecium caudatum using the original electric arc plasmatron. The decrease in the number of experimental cells has been shown, which may indicate membrane destructive pathology due to oxidative stress induced by the plasma impact. It is concluded that reactions at the population level of Paramecium caudatum are effective indices of primary information about plasma radiation cytotoxicity.

Бактерицидный эффект низкотемпературной плазмы в отношении Helicobacter pylori in vitro

Бактерицидный эффект низкотемпературной плазмы в отношении Helicobacter pylori in vitro

Low-temperature plasma on peri-implant-related biofilm and gingival tissue.

Evaluate the effect of low-temperature plasma (LTP) on an anaerobic biofilm and on the biological response of an in vitro reconstituted gingival epithelium tissue. Porphyromonas gingivalis W83 biofilm was cultured on titanium discs and reconstituted gingival tissues were submitted to similar treatment conditions. LTP1-plasma treatment for 1minute, LTP3-plasma treatment for 3minute, CHX-0.2% chlorhexidine for 1minute, GAS-gas only (no plasma) for 3minute, and NEGATIVE-no treatment. TRITON group was included as a positive control for tissue analysis. Counting of viable colony forming units (CFU/mL) and confocal laser scanning microscopy were performed to evaluate LTP's antimicrobial effect. EpiGingival tissue was evaluated through cytotoxocity, viability, histology, and imunnohistochemistry (Ki67, vascular endothelial growth factor-A vascular endothelial growth factor A [VEGF-A], and terminal deoxynucleotidyl transferase dUTP nick end labeling terminal deoxynucleotidyl transferase dutp nick end labeling [TUNEL] expression). LTP1 and LTP3 presented significantly different reduced CFU/mL reduction in comparison to the negative control (Ρ<0.001), but it was not as effective as the positive control (CHX). Low cytotoxicity and high viability were observed in gingival epithelium of NEGATIVE, GAS, CHX, and both LTP groups. The morphologic analysis of gingival epithelium revealed minor cell damage in the plasma groups (score 1). LTP1, LTP3, GAS, and NEGATIVE groups exhibited less than 5% of basal layer positive cells. LTP1, LTP3, GAS, and CHX groups were not positive for TUNEL assay. LTP1 and LTP3 showed the most positivity for VEGF. LTP treatment can be considered as an effective method for reducing P. gingivalis biofilm on implant surfaces, while being safe for the gingival epithelium. Furthermore, plasma treatment may be associated with cell repair.

Analysis of curative effect of low temperature plasma combined with collagenase guided by computer tomography on lumbar intervertebral disc herniation

Objective To investigate the efficacy of CT-guided low-temperature plasma-mediated radiofrequency ablation combined with collagenase in the treatment of prolapse of lumbar intervertebral disc. Methods A total of fifty-eight patients with prolapse of lumbar intervertebral disc received low-temperature plasma-mediated radiofrequency ablation combined with collagenase were retrospectively analyzed. Changes in the degree of pain before and after operation were evaluated by VAS. The duration of postoperative recovery and pain relief were recorded. Risk factors for postoperative pain relief were analyzed. Results All patients underwent successful puncture, and no neurological injury, intervertebral disc infection, and no complications such as spinal cord and vascular organ injury. Postoperative follow-up for 6 months, the mean VAS was 3 points after 2 weeks. The mean VAS was 2.6 points at 1 month postoperatively, which was statistically different from the 2 weeks postoperatively (P 0.05). MacNab evaluation was excellent. A total of 30 patients (51.7%) had a good evaluation of 15 patients (25.8%), and 8 patients (15.5%) had a good evaluation. The patients with poor results were 5 patients (7%). The excellent rate reached 89.7%. Conclusions Low-temperature plasma-mediated radiofrequency ablation combined with collagenase can effectively treat prolapse of lumbar intervertebral disc. These two techniques are both characterized by safety and minimal trauma. Thus, this method is recommended for combined minimally invasive interventional therapy in addition to conservative therapy and open surgery. Key words: Low-temperature plasma-mediated radiofrequency ablation; Collagenase; Prolapse of lumbar intervertebral disc; Computer tomography

Effect of low-temperature plasma on the degradation of omethoate residue and quality of apple and spinach

Dielectric barrier corona discharge was developed to generate low-temperature plasma (LTP) to treat apple and spinach samples contaminated with omethoate. Experimental results showed that, after 20 min exposure, the degradation rate of omethoate residue in apple and spinach was (94.55 ± 0.01)% and (95.55 ± 0.01)%, respectively. When the treatment time was shorter than 20 min, the contents of moisture, vitamin C and beta-carotene were not affected by LTP. Exploration of related mechanisms suggested that LTP might destroy unsaturated double bonds of omethoate and produce phosphate ion, eventually leading to omethoate destruction. It is concluded that appropriate dosage of LTP can effectively degrade omethoate residue in fruits and vegetables without affecting their quality.

Microarry Analysis Identifies Activation Of Multiple Signalling Pathways In Primary Prostate Epithelial Cells By Low Temperature Plasma

We have previously reported the killing effects of Low Temperature Plasma (LTP) on primary prostate epithelial cells, of both normal and cancerous origin, via necrosis [1] following initial DNA damage. However it was evident that a population of cells was resistant to LTP treatment. To discern possible survival mechanisms in treated cells; the gene expression of 6 samples (4 cancers and 2 matched normal) was analysed 2 hours post-treatment, on a transcriptome wide level, by microarray. Initial analysis found alteration in the expression of 646 transcripts with significant activation of Notch, NF-kB, Nrf2 and AP-1 signalling in our primary cells. Pathway activation was subsequently validated by qRT-PCR in four different patient-derived prostate cultures to give a robust LTP-induced expression signature. Upstream effector activation was then confirmed by immunofluorescence and Western blot. We found as other groups have; [2, 3] accumulation of Nrf2 in response to LTP, alongside AP-1 activation [4, 5] – through phosphorylation of both JNK and Jun. The Notch signalling pathway is typically described in relation to stem cell maintenance and we observed LTP induced Notch activation through release of its intracellular domain (NICD) that then acts as a nuclear transcription factor. Tumours are innately heterogeneous and contain multiple cell populations, both intrinsic and recruited. We have established that our cultures contain three readily identifiable epithelial cell pools that can be separated to permit further analysis.[6] Preliminary investigation has found that the progenitor epithelial cells respond in greater measure than their more differentiated progeny, suggesting that they are more resistant to plasma. Similar observations of prostate stem cell resistance have been made with radiotherapy.[7] However, if these stem-like cells can be targeted – LTP may have a greater killing effect if utilized in prostate cancer treatments. Download : Download high-res image (151KB) Download : Download full-size image Figure – Pathway activation in primary prostate cancer epithelial culture; Nrf2 accumulation, AP-1 activation by JNK and Jun phosphorylation and Notch cleavage, with release of NICD by LTP. U – Untreated, T- Treated. Samples taken 0.5 and 2 hours following treatment with 3 minutes LTP.

Cold atmospheric pressure ambient air plasma inhibition of pathogenic bacteria on the surface of black pepper

In present study, the inhibition effect of low temperature plasma on Bacillus subtilis, Escherichia coli, Salmonella Enteritidis and B. subtilis endospores inoculated on the surface of black peppercorns was studied. Plasma was generated by Diffuse Coplanar Surface Barrier Discharge (DCSBD) at atmospheric pressure in ambient air. Plasma treatment time of 300 s led to log10 CFU/g reduction of B. subtilis from 7.36 to 2.30 and B. subtilis endospores from 4.42 to 2.39. Plasma treatment reduced the number of E. coli and Salmonella Enteritidis to below detection level (1.0 log10 CFU/g) from initial populations of 7.45 log10 CFU/g and 7.60 log10 CFU/g, respectively. The inactivation kinetics was explained by Weibull model. Decimal reduction times (D-values) for B. subtilis, E. coli, Salmonella Enteritidis, and B. subtilis endospores were determined as 43 s, 47 s, 58 s, and 142 s, respectively. The surface morphology observed by Scanning Electron Microscopy showed no significant changes after the plasma treatment. The influence of plasma on chemical bonds on the surface and inside the peppercorns was studied by Attenuated Total Reflectance – Fourier Transform Infrared Spectroscopy.

Mobile plants for plasma chemical water treatment

Water is a valuable natural resource. It provides an exceptional role in metabolic processes, which are the basis of life. The negative factor of human activity is pollution of the environment, including water resources. Municipal sewage treatment is an urgent environmental problem. It exists both in Russia and abroad. Despite all the measures and methods used to treat wastewater, pollutants continue to flow into water bodies. The most dangerous pollutants are heavy metals, organic substances (proteins, fats, carbohydrates). To solve this problem, both traditional and modern methods are proposed. The purpose of this study is to develop an energy-efficient, eco-friendly mobile device for water purification based on the action of low-temperature nonequilibrium plasma. The developed installation has a small weight of 20 to 50 kg, occupies a small area. To move it you can use any vehicle. Model samples and samples from the municipal sewerage network were prepared as experimental samples. The effect of low-temperature plasma showed a high degree of purification with a single exposure at low values of electric energy consumption per unit of water to be purified. Reduction of the concentration of ammonium-ion and ammonium nitrogen reaches 96-98%.

Low temperature plasma induced apoptosis in CNE‐2Z cells through endoplasmic reticulum stress and mitochondrial dysfunction pathways

This study is designed to investigate the effect of low temperature plasma (LTP) on the apoptosis of CNE‐2Z cell (human nasopharyngeal carcinoma cell line) and the potential mechanisms. We find out that LTP provoked the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in CNE‐2Z cells and significantly inhibit the cell viability and induce cell apoptosis. Furthermore, the antioxidant N‐acetyl cysteine (NAC) almost completely blocked LTP‐induced apoptosis. LTP triggered mitochondrial and endoplasmic reticulum (ER) stress‐induced apoptotic pathways indicated by significant upregulation of CHOP, p53, and Bax‐to‐Bcl‐2 ratio. This work will provide the molecular theoretical basis of clinical application of LTP for the treatment of human nasopharyngeal carcinoma.

Effect of nonthermal plasma on the properties of a resinous liner submitted to aging

Statement of problemThe properties, such as softness and viscoelasticity, of a resinous reliner can deteriorate and extrinsic elements can become incorporated, making surface protection of the reliner material essential. PurposeThe purpose of this in vitro study was to evaluate the effect of low temperature plasma on Coe-Soft resinous reliner, submitted to aging in artificial saliva for up to 180 days. Sorption, solubility, Shore A hardness, surface energy, and topographic characteristics were analyzed by scanning electronic microscopy (SEM) and energy-dispersive spectroscopy (EDS). Material and methodsForty-four specimens were fabricated and distributed in 2 groups: nonplasma reliner (control group) and reliner with plasma (plasma group). The plasma was applied with a mixture of 70% hexamethyldisiloxane, 20% O, and 10% Ar. Total work pressure was maintained at a constant 20 Pa for 30 minutes of deposition. The specimens were analyzed before and after aging in an incubator with immersion in artificial saliva for 30, 90, and 180 days. The quantitative data were submitted to 2-way ANOVA and the Tukey test (α=.05), while qualitative data were compared visually. ResultsThe control group presented lower Shore A hardness values only in the initial period, and surface energy increased with aging for both groups until 90 days. Greater sorption percentage values were encountered at 180 days in the plasma group. Greater solubility values were encountered in the control group in all periods. ConclusionsPlasma is an option for the protection of the material studied because the deposited film remained on the surface of the reliner material after aging.

Killing effect and its mechanism of low-temperature plasma on different human cancer cell lines

Objective: To investigate the killing effect of low-temperature plasma (LTP) on HepG2, A549 and HeLa cell lines and explore its possible mechanism. Methods: The inhibitory effect of LTP on the proliferation of HepG2, A549 and HeLa cells was determined by MTT assay. Transmission electron microscopy was used to observe the ultrastructural changes of HepG2, A549 and HeLa cells treated with LTP. Cell apoptosis was detected by Muse cytometry. Western blot was used to detect the expression of apoptosis-related proteins. Results: The survival rates of LTP-irradiated HepG2 cells (irradiated for 107 s), HeLa cells (irradiated for 121 s) and A549 cells (irradiated for 127 s) were 50%. LTP destroyed the ultrastructure of HepG2, A549 and HeLa cells to different degrees, showing nuclear fragmentation and organelle damages. The apoptosis rates of the three cell lines were increased at 24 h after exposure to LTP for 1/6 IC50 irradiation time. Furthermore, LTP irradiation also suppressed the protein expression of Bcl-2 and XRCC1 and increased that of Bax. Conclusions: LTP has an obvious killing effect on HepG2, A549 and HeLa cancer cell lines. This effect may be related to the induction of cell apoptosis and inhibition of DNA repair.

Effects of low temperature plasma on prostate cancer cells using the Bovie Medical J‐Plasma® device

The efficacy of low temperature plasma generated by an atmospheric pressure plasma jet, J‐Plasma system (™Bovie Medical Corporation), is studied for its therapeutic effects against the DU145 prostate cancer cell line. The DU145 cells in complete culture media were treated with different exposure times and different J‐Plasma system parameters. The optimum settings of the J‐Plasma system were identified based on the cancer cell viability at 0, 12, 24, 48, and 72 h post‐low temperature plasma treatments. The results indicate that J‐Plasma killing and cell viability was exposure time dependent and induced a reduction in cell proliferation and delayed killing effect.

Effect of low temperature plasma on the functional properties of basmati rice flour.

The present study deals with the application of low temperature plasma on basmati rice flour and its effect on functional properties such as gel hydrations properties, flour hydration properties, gelatinization temperatures and antioxidant properties. The water holding capacity and water binding capacity were observed to be increased with increase in plasma power and time of treatment as the air plasma is known to make the surface more hydrophilic. XRD analysis revealed there is no significance difference in the crystalline structure after the plasma treatment. DSC shows a decrease in peak temperatures (Tp) after the treatment. Hot paste viscosities were observed to be decease from 692 to 591 BU was corresponded to decrease in peak temperature. The total polyphenolic content and reducing power was observed to be increased. The effects of plasma treatment on functional groups of polyphenols were observed by changes in absorption intensities using FTIR. This study demonstrates that the low temperature plasma treatmentis capable of improving the functional properties of basmati rice.

Effect of low-temperature plasma on chitosan-coated PEEK polymer characteristics

Low-temperature plasma effect on changes of physicochemical properties of plastic polymer polyetheretherketone (PEEK) was investigated. Despite extensive use of PEEK, information about adhesion to this polymer is limited. The adhesive and energetic properties of biomaterial and after chitosan modification were studied by contact angles measurements and surface free energy evaluation using the acid-base LWAB theory and contact angle hysteresis (CAH) model. Modification by chitosan can enhance antibacterial properties, native haemostatic and the polymer biocompatibility. Plasma modification led to variation in surface chemistry and morphology determined by an optical profilometer. After air/nitrogen plasma treatment a relatively hydrophobic character of PEEK was changed into more hydrophilic, significant differences in the wettability of sample were observed. Though, practically no differences in thermal and mechanical properties were noticed. The profilometer pictures showed an increase in the surface roughness of plasma modified PEEK due to the formation of additional polar groups with oxygen and nitrogen on the surface. Plasma treated polyetheretherketone surfaces had better adhesive features. Novel and stable chitosan-coated PEEK biomaterials were prepared applicable for different industries, mainly pharmacy and reconstructive medicine.

Short and long time effects of low temperature Plasma Activated Media on 3D multicellular tumor spheroids.

This work investigates the regionalized antiproliferative effects of plasma-activated medium (PAM) on colon adenocarcinoma multicellular tumor spheroid (MCTS), a model that mimics 3D organization and regionalization of a microtumor region. PAM was generated by dielectric barrier plasma jet setup crossed by helium carrier gas. MCTS were transferred in PAM at various times after plasma exposure up to 48 hours and effect on MCTS growth and DNA damage were evaluated. We report the impact of plasma exposure duration and delay before transfer on MCTS growth and DNA damage. Local accumulation of DNA damage revealed by histone H2AX phosphorylation is observed on outermost layers and is dependent on plasma exposure. DNA damage is completely reverted by catalase addition indicating that H2O2 plays major role in observed genotoxic effect while growth inhibitory effect is maintained suggesting that it is due to others reactive species. SOD and D-mannitol scavengers also reduced DNA damage by 30% indicating that and OH* are involved in H2O2 formation. Finally, PAM is able to retain its cytotoxic and genotoxic activity upon storage at +4 °C or −80 °C. These results suggest that plasma activated media may be a promising new antitumor strategy for colorectal cancer tumors.