Elucidating the bacterial inactivation mechanism by argon cold atmospheric pressure plasma jet through spectroscopic and imaging techniques.

AIMS: This study aims to assess the potential bacterial inactivation pathway triggered by argon (Ar) cold atmospheric pressure plasma jet (CAPJ) discharge using spectroscopic and imaging techniques. METHODS AND RESULTS: Electrical and reactive species of the Ar CAPJ discharge was characterized. The chemical composition and morphology of bacteria pre- and post-CAPJ exposure were assessed using Fourier transform infrared (FTIR), Raman micro-spectroscopy, and transmission electron microscopy (TEM). A greater than 6 log reduction of Escherichia coli and Staphylococcus aureus was achieved within 60 and 120 s of CAPJ exposure, respectively. Extremely low D-values (<20 s) were recorded for both the isolates. The alterations in the FTIR spectra and Raman micro-spectra signals of post-CAPJ exposed bacteria revealed the degree of destruction at the molecular level, such as lipid peroxidation, protein oxidation, bond breakages, etc. Further, TEM images of exposed bacteria indicated the incurred damages on cell morphology by CAPJ reactive species. Also, the inactivation process varied for both isolates, as evidenced by the correlation between the inactivation curve and FTIR spectra. It was observed that the identified gas-phase reactive species, such as Ar I, O I, OH•, NO+, OH+, NO2-, NO3-, etc. played a significant role in bacterial inactivation. CONCLUSIONS: This study clearly demonstrated the effect of CAPJ exposure on bacterial cell morphology and molecular composition, illuminating potential bacterial inactivation mechanisms.

Non-thermal atmospheric pressure plasma induces selective cancer cell apoptosis by modulating redox homeostasis.

BACKGROUND: Anticancer treatments aim to selectively target cancer cells without harming normal cells. While non-thermal atmospheric pressure plasma (NTAPP) has shown anticancer potential across various studies, the mechanisms behind its selective action on cancer cells remain inadequately understood. This study explores the mechanism of NTAPP-induced selective cell death and assesses its application in cancer therapy. METHODS: We treated HT1080 fibrosarcoma cells with NTAPP and assessed the intracellular levels of mitochondria-derived reactive oxygen species (ROS), mitochondrial function, and cell death mechanisms. We employed N-acetylcysteine to investigate ROS's role in NTAPP-induced cell death. Additionally, single-cell RNA sequencing was used to compare gene expression in NTAPP-treated HT1080 cells and human normal fibroblasts (NF). Western blotting and immunofluorescence staining examined the expression and nuclear translocation of nuclear factor erythroid 2-related factor 2 (NRF2), a key antioxidant gene transcription factor. We also evaluated autophagy activity through fluorescence staining and transmission electron microscopy. RESULTS: NTAPP treatment increased ROS levels and induced mitochondrial dysfunction, leading to apoptosis in HT1080 cells. The involvement of ROS in selective cancer cell death was confirmed by N-acetylcysteine treatment. Distinct gene expression patterns were observed between NTAPP-treated NF and HT1080 cells, with NF showing upregulated antioxidant gene expression. Notably, NRF2 expression and nuclear translocation increased in NF but not in HT1080 cells. Furthermore, autophagy activity was significantly higher in normal cells compared to cancer cells. CONCLUSIONS: Our study demonstrates that NTAPP induces selective cell death in fibrosarcoma cells through the downregulation of the NRF2-induced ROS scavenger system and inhibition of autophagy. These findings suggest NTAPP's potential as a cancer therapy that minimizes damage to normal cells while effectively targeting cancer cells.

Low Temperature Plasma-Assisted Double Anodic Dissolution: A New Approach for the Synthesis of GdFeO3 Perovskite Nanoparticles.

Orthorhombic perovskite GdFeO3 nanostructures are promising materials with multiferroic properties. In this study, a new low-temperature plasma-assisted approach is developed via dual anodic dissolution of solid metallic precursors for the preparation of perovskite GdFeO3 nanoparticles (NPs) that can be collected both as colloids as well as deposited as a thin film on a substrate. Two solid metallic foils of Gd and Fe are used as precursors, adding to the simplicity and sustainability of the method. The formation of the orthorhombic perovskite GdFeO3 phase is supported by high-resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman measurements, while a uniform elemental distribution of Gd, Fe, and O is confirmed by energy dispersive X-ray spectroscopy, proving the successful preparation of ternary compound NPs. The magnetic properties of the NPs show zero remnant magnetization typical of antiferromagnetic materials, and saturation at high fields that can be caused by spin interaction between Gd and Fe magnetic sublattices. The formation mechanism of ternary compound NPs in this novel plasma-assisted method is also discussed. This method is also modified to demonstrate the direct one-step deposition of thin films, opening up opportunities for their future applications in the fabrication of magnetic memory devices and gas sensors.

Plasma Control: A Review of Developments and Applications of Plasma Medicine Control Mechanisms.

Cold atmospheric plasmas (CAPs) within recent years have shown great promise in the field of plasma medicine, encompassing a variety of treatments from wound healing to the treatment of cancerous tumors. For each subsequent treatment, a different application of CAPs has been postulated and attempted to best treat the target for the most effective results. These treatments have varied through the implementation of control parameters such as applied settings, electrode geometries, gas flow, and the duration of the treatment. However, with such an extensive number of variables to consider, scientists and engineers have sought a means to accurately control CAPs for the best-desired effects in medical applications. This paper seeks to investigate and characterize the historical precedent for the use of plasma control mechanisms within the field of plasma medicine. Current control strategies, plasma parameters, and control schemes will be extrapolated through recent developments and successes to gain better insight into the future of the field and the challenges that are still present in the overall implementation of such devices. Proposed approaches, such as data-driven machine learning, and the use of closed-loop feedback controls, will be showcased as the next steps toward application.

Natural Fiber-Reinforced Composite Incorporated with Anhydride-Cured Epoxidized Linseed-Oil Resin and Atmospheric Pressure Plasma-Treated Flax Fibers.

Fiber-reinforced composites (FRCs) represent a promising class of engineering materials due to their mechanical performance. However, the vast majority of FRCs are currently manufactured using carbon and glass fibers, which raises concerns because of the difficulties in recycling and the reliance on finite fossil resources. On the other hand, the use of natural fibers is still hampered due to the problems such as, e.g., differences in polarity between the reinforcement and the polymer matrix components, leading to a significant decrease in composite durability. In this work, we present a natural fiber-reinforced composite (NFRC), incorporating plasma pre-treated flax fibers as the reinforcing element, thermoplastic polylactic acid (PLA) as a matrix, and a key point of the current study-a thermoset coating based on epoxidized linseed oil for adhesion improvement. Using atmospheric plasma-jet treatment allows for increasing the fiber's surface energy from 20 to 40 mN/m. Furthermore, a thermoset coating layer based on epoxidized linseed oil, in conjunction with dodecyl succinic anhydride (DDSA) as a curing agent and 2,4,6-tris(dimethyl amino methyl) phenol (DMP-30) as a catalyst, has been developed. This coated layer exhibits a decomposition temperature of 350 °C, and there is a substantial increase in the dispersive surface-energy part of the coated flax fibers from 8 to 30 mN/m. The obtained natural fiber-reinforced composite (NFRC) was prepared by belt-pressing with a PLA film, and its mechanical properties were evaluated by tensile testing. The results showed an elastic modulus up to 18.3 GPa, which is relevant in terms of mechanical properties and opens up a new pathway to use natural-based fiber-reinforced bio-based materials as a convenient approach to greener FRCs.

Microwave Plasma Pencil for Surface Treatment: Numerical Study of Electromagnetic Radiation and Experimental Verification.

An atmospheric pressure plasma source of the microwave plasma pencil type utilizing a coaxial line is presented. The generated plasma takes the form of a cylinder up to about 30 mm long and up to 5 mm in diameter. It is suitable for surface sterilization, surface treatment, and material processing. This study numerically analyzes the electromagnetic radiation emitted by the plasma pencil, which compromises performance and poses safety risks. Electric field distributions, radiation patterns, the ratio of the power entering the discharge to the incident wave power, and the ratio of radiated power to entering power were numerically investigated for different plasma parameters and pencil lengths. Results indicate that increasing electron density, gas temperature, plasma length, and pencil length increases the radiated power by up to more than 60% of the entering power, and the radiation patterns can be highly non-uniform with strong backward lobe. The numerical finding were qualitatively confirmed experimentally. It was also found that it is possible to reduce radiation from the device by using appropriately designed cones, the presence of which does not impede its performance.

Combatting the antigenicity of common ragweed pollen and its primary allergen Amb a 1 with cold atmospheric pressure air plasma.

Airborne allergens, especially those originating from various types of pollen, significantly compromise the health and well-being of individuals on a global scale. Here, cold atmospheric pressure plasma (CAP) created in ambient air was used to treat highly allergenic and invasive Ambrosia artemisiifolia pollen. Immunoassays were used to evaluate the impact of CAP on the principal A. artemisiifolia allergen Amb a 1, demonstrating that > 90 % reduction in antigenicity could be achieved. Chemical analyses using Fourier Transform infrared revealed that CAP induced significant alterations to proteins on the surface of pollen grains, resulting in a 43 % increase in the amide I peak area and a 57 % increase in the amide II peak area. These findings were corroborated by Raman and X-ray photoelectron spectroscopy, which indicated that the protein modifications induced by CAP were due to carbonylation and nitration/nitrosylation processes. Beyond protein transformations, CAP also induced notable oxidation and modification of lipid-like compounds, polysaccharides and sporopollenin. Evident transformations at the chemical level translated into morphological changes at the grain surface, manifesting as increased roughness via significant outer-layer etching. These findings underscore the potential of CAP technology as a viable approach for mitigating against the allergenicity of pollen, providing a deeper understanding into the underlying chemical mechanisms.

High-Performance Low-Voltage Thin-Film Transistors: Experimental and Simulation Validation of Atmospheric Pressure Plasma-Assisted Li5AlO4 Metal Oxide Solution Processing.

Metal oxide materials processed using solution methods have garnered significant attention due to their ability to efficiently and affordably create transparent insulating layers or active channel layers on various substrates for thin-film transistors (TFTs) used in modern electronics. The key properties of TFTs largely depend on how charge carriers behave near the thin layer at the semiconductor and dielectric interface. Effectively controlling these characteristics offers a straightforward yet effective approach to enhancing device performance. In this study, we propose a novel strategy utilizing atmospheric pressure plasma (APP) treatment to modulate the electrical properties of dielectric thin films and the interfaces between dielectric and semiconductor layers in TFTs processed by using solution methods. Through APP exposure, significant improvements in key TFT parameters were achieved for solution-processed TFTs. Interface states have been reduced from 1013 to 1011 cm-2, and the on/off current ratio has increased from 103 to 106 while maintaining a high field-effect mobility of 34 cm2 V-1 s-1. Additionally, UV-visible spectroscopy and X-ray analysis have confirmed the effectiveness of APP treatment in controlling interface states and traps, leading to overall performance enhancements in the TFTs. Furthermore, our experimental findings have been systematically validated using technology computer-aided design (TCAD) simulations of fabricated TFTs.

Atmospheric pressure plasma preconditioning reduces oxygen and glucose deprivation induced human neuronal SH-SY5Y cells apoptosis by activating protective autophagy and ROS/AMPK/mTOR pathway.

Reactive oxygen species (ROS)/reactive nitrogen species (RNS) exert a "double edged" effect on the occurrence and development of ischemic stroke. We previously indicate that atmospheric pressure plasma (APP) shows a neuroprotective effect in vitro based on the ROS/RNS generations. However, the mechanism is still unknown. In this work, SH-SY5Y cells were treated with oxygen and glucose deprivation (OGD) injuries for stimulating the ischemic stroke pathological injury process. A helium APP was used for SH-SY5Y cell treatment for evaluating the neuroprotective impacts of APP preconditioning against OGD injuries with the optimized parameters. During the preconditioning, APP significantly raised the extracellular and intracellular ROS/RNS production. As a result, APP preconditioning increased SH-SY5Y cell autophagy by elevating LC3-II/LC3-I ratio and autophagosome formation. Meanwhile, APP preconditioning reduced cell apoptosis caused by OGD with the increased APP treatment time, which was abolished by pretreatment with autophagy inhibitor 3-methyladenine (3-MA). The ROS scavenger N-acetyl-L-cysteine (NAC) alone or combined with NO scavenger carboxy-PTIO abolished the APP preconditioning induced SH-SY5Y autophagy and the cytoprotection, whereas the NO scavenger alone did not. In addition, we observed the elevated phosphorylation of AMP-activated protein kinase (AMPK) and decreased phosphorylation of mammalian target of rapamycin (mTOR) in APP treated SH-SY5Y cells. This effect was attenuated by AMPK inhibitor Compound C (CC), the ROS scavenger NAC and autophagy inhibitor 3-MA. Furthermore, the cytoprotective effect of APP was preliminarily confirmed in the rats of middle cerebral artery occlusion (MCAO) model. Results showed that APP inhalation by rats during MCAO process could improve neurological functions, reduce cell apoptosis in brain tissues and decrease cerebral infarct volume. Our data suggested that ROS produced by APP preconditioning played a vital role in the neuroprotective effect of SH-SY5Y cells against OGD injuries by activating autophagy and ROS/AMPK/mTOR pathway.

Effects of different plasma treatments on bonding properties of zirconia.

This in vitro study was to evaluate the effect of different non-thermal atmospheric pressure plasma (NTP) on shear bond strength (SBS) between yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) and self-adhesive resin cement. In this study, The Y-TZP specimens were divided into 4 groups according to the surface treatment methods as follows: Control (no surface treatment), Sb (Sandblasting), AP(argon NTP), and CP(20 % oxygen and 80 % argon combination NTP). Y-TZP specimens were randomly selected from each group to observe and test the following indexes: scanning electron microscope to observe the surface morphology; atomic force microscope to detect the surface roughness; contact angle detector to detect the surface contact angle; energy spectrometer to analyze the surface elements. Then, resin cement (Rely X-U200) was bonded to human isolated teeth with Y-TZP specimens to measure SBS. The results showed that for the SE test, the NTP group was significantly higher than the control group (p < 0.05). The results of the SBS test showed that the SBS values of the NTP group were significantly higher than those of the other groups, regardless of the plasma treatment (p < 0.05). However, there was no significant difference between groups AP and CP in a test of SBS (p > 0.05). This study shows that non-thermal atmospheric pressure plasma can improve the shear bond strength of Y-TZP by increasing the surface energy. The addition of oxygen ratio to argon is more favorable to increase the shear bond strength and is worth further investigation.

Surface Analysis of Stainless Steel Electrodes Cleaned by Atmospheric Pressure Plasma.

The Z-pinch device is a critical component in inertial confinement fusion, where stainless steel electrodes must withstand high current densities of up to MA/cm2. Gases and difficult-to-remove impurities adhering to the electrode surfaces can ionize, significantly impacting the device's electrical conductivity efficiency. In this paper, the surface of stainless steel electrodes was subjected to cleaning using a large-area plasma jet under atmospheric pressure. The wettability, chemical composition, and chemical state of the electrode surface were characterized using a water contact angle measuring instrument and X-ray photoelectron spectroscopy (XPS). The cleaning effect under different discharge parameters was systematically analyzed. The results revealed a significant reduction in the content of carbon pollutants on the surface of stainless steel electrodes, decreasing from 62.95% to a minimum of 37.68% after plasma cleaning. Moreover, the water contact angle decreased from 70.76° to a minimum of 29.31°, and the content of water molecules adsorbed on the surface decreased from 17.31% to a minimum of 5.9%. Based on the evolution process of micro-element content and chemical state on the surface of stainless steel electrode, the cleaning process of adhering substances on the surface by atmospheric pressure plasma was analyzed by the layered cleaning model for surface pollutants on stainless steel.

Chemical and physical changes induced by cold plasma treatment of foods: A critical review.

Cold plasma treatment is an innovative technology in the food processing and preservation sectors. It is primarily employed to deactivate microorganisms and enzymes without heat and chemical additives; hence, it is often termed a "clean and green" technology. However, food quality and safety challenges may arise during cold plasma processing due to potential chemical interactions between the plasma reactive species and food components. This review aims to consolidate and discuss data on the impact of cold plasma on the chemical constituents and physical and functional properties of major food products, including dairy, meat, nuts, fruits, vegetables, and grains. We emphasize how cold plasma induces chemical modification of key food components, such as water, proteins, lipids, carbohydrates, vitamins, polyphenols, and volatile organic compounds. Additionally, we discuss changes in color, pH, and organoleptic properties induced by cold plasma treatment and their correlation with chemical modification. Current studies demonstrate that reactive oxygen and nitrogen species in cold plasma oxidize proteins, lipids, and bioactive compounds upon direct contact with the food matrix. Reductions in nutrients and bioactive compounds, including polyunsaturated fatty acids, sugars, polyphenols, and vitamins, have been observed in dairy products, vegetables, fruits, and beverages following cold plasma treatment. Furthermore, structural alterations and the generation of volatile and non-volatile oxidation products were observed, impacting the color, flavor, and texture of food products. However, the effects on dry foods, such as seeds and nuts, are comparatively less pronounced. Overall, this review highlights the drawbacks, challenges, and opportunities associated with cold plasma treatment in food processing.

Adhesion Properties and Stability of Polar Polymers Treated by Air Atmospheric Pressure Plasma.

This study continues the discussion on the surface modification of polymers using an atmospheric pressure plasma (APP) reactor in air. These results complement prior research focusing on nonpolar polymers. Polymers, such as polyethylene terephthalate, polyetheretherketone, and polymethyl methacrylate, containing structurally bonded oxygen are studied, representing a range of properties such as oxygen content, crystalline/amorphous structure, polarity, functionality, and aliphatic/aromatic structure. APP induces superior wetting properties on the hydrophilic polymer surfaces with rapid and uniform modification within 0.5 s of exposure. The amorphous structures undergo additional modification for longer exposure. Moreover, the aliphatic chain structures require longer plasma exposure to reach surface modification equilibrium. The polar polymers reach a limit level of modification corresponding to a minimum water contact angle of about 50°. The surface polarity increases on average by a factor of approximately two. The equilibrium values of the adhesion work attained after post-processing recovery fall within a limited range of about 100-120 mJ/m2. The enhancement of surface functionality through the creation of oxidized groups primarily depends on the initial oxygen content and reaches a limit of about 40 at.% oxygen. The surface properties of the treated polar surfaces exhibit good stability, comparable to that of the previously tested nonpolar polymers.

Cold Physical Plasma Reduces Motility of Various Bone Sarcoma Cells While Remodeling the Cytoskeleton.

BACKGROUND/AIM: Cold physical plasma (CPP) has emerged as an effective therapy in oncology by inducing cytotoxic effects in various cancer cells, including chondrosarcoma (CS), Ewing's sarcoma (ES), and osteosarcoma (OS). The current study investigated the impact of CPP on cell motility in CS (CAL-78), ES (A673), and OS (U2-OS) cell lines, focusing on the actin cytoskeleton. MATERIALS AND METHODS: The CASY Cell Counter and Analyzer was used to study cell proliferation and determine the optimal concentrations of fetal calf serum to maintain viability without stimulation of cell proliferation. CellTiter-BlueCell viability assay was used to determine the effects of CPP on the viability of bone sarcoma cells. The Radius assay was used to determine cell migration. Staining for Deoxyribonuclease I, G-actin, and F-actin was used to assay for the effects on the cytoskeleton. RESULTS: Reductions in cell viability and motility were observed across all cell lines following CPP treatment. CPP induced changes in the actin cytoskeleton, leading to decreased cell motility. CONCLUSION: CPP effectively reduces the motility of bone sarcoma cells by altering the actin cytoskeleton. These findings underscore CPP's potential as a therapeutic tool for bone sarcomas and highlight the need for further research in this area.

Reactive Species Risk Assessment Using Optimized HET-CAM Safety Evaluation of Feed Gas-Modified Gas Plasma Technology and Anticancer Drugs.

Clinical therapies, including dermatology and oncology, require safe application. In vitro experiments allow only limited conclusions about in vivo effects, while animal studies in, e.g., rodents have ethical constraints at a large scale. Chicken embryos lack pain reception until day 15 postfertilization, making the in ovo model a suitable alternative to in vivo safety assessment. In addition, the hen's egg test on chorioallantoic membrane assay allows irritation potential analysis for topical treatments, but standardized analysis has been limited so far. Medical gas plasma is a topical, routine, approved dermatology treatment. Recent work suggests the potential of this technology in oncology. Its main mode of action is the release of various reactive species simultaneously. Intriguingly, varying plasma feed gas compositions generates customized reactive species profiles previously shown to be optimized for specific applications, such as skin cancer treatment. To support clinical implications, we developed a novel chicken embryo CAM scoring and study scheme and employed the model to analyze 16 different plasma feed gas settings generated by the atmospheric pressure plasmajet kINPen, along with common anticancer drugs (e.g., cisplatin) and physiological mediators (e.g., VEGF). Extensive gas- and liquid-phase plasma reactive species profiling was done and was found to have a surprisingly low correlation with irritation potential parameters. Despite markedly different reactive species patterns, feed gas-modulated kINPen plasma was equally tolerated compared to standard argon plasma. CAM irritation with gas plasmas but not anticancer agents was reversed 48 h after treatment, underlining the only temporary tissue effects of medical gas plasma. Our results indicate a safe therapeutic application of reactive species.

Pea protein-inulin conjugate prepared by atmospheric pressure plasma jet combined with glycosylation: structure and emulsifying properties.

Pea protein is one of plant proteins with high nutritional value, but its lower solubility and poor emulsifying properties limit its application in food industry. Based on wet-heating glycosylation of pea protein and inulin, effects of discharge power of atmospheric pressure plasma jet (APPJ) on structure, solubility, and emulsifying ability of pea protein-inulin glycosylation conjugate were explored. Results indicated that the APPJ discharge power did not affect the primary structure of pea protein. However, changes in secondary and spatial structure of pea protein were observed. When APPJ discharge power was 600 W, the solubility of glycosylation conjugate was 75.0% and the emulsifying stability index was 98.9 min, which increased by 14.85 and 21.95% than that of only glycosylation sample, respectively. These findings could provide technical support for APPJ treatment combination with glycosylation to enhance the physicochemical properties of plant-based proteins.

Non-thermal atmospheric-pressure plasma exposure as a practical method for improvement of Brassica juncea seed germination.

Here we report that non-thermal atmospheric-pressure plasma exposure can improve Brassica juncea (leaf mustard) seed germination rate from 50 % to 98 %. The commercially relevant germination rate was achieved by plasma exposure for only 10 minutes and the effect sustains at least for one month under an appropriate storage condition. Improved germination by plasma exposure was also observed for Brassica rapa subsp. pekinensis (Chinese cabbage) seeds. The plasma device used is simple. No pure gas flow system is necessary and it is easy to handle. A large number of seeds can be treated by simply scaling up the device. Plasma exposure can be a practical method for improving seed germination of crop plants important for agriculture.

Cold Atmospheric Pressure Plasma-Activated Medium Modulates Cellular Functions of Human Mesenchymal Stem/Stromal Cells In Vitro.

Cold atmospheric pressure plasma (CAP) offers a variety of therapeutic possibilities and induces the formation of reactive chemical species associated with oxidative stress. Mesenchymal stem/stromal cells (MSCs) play a central role in tissue regeneration, partly because of their antioxidant properties and ability to migrate into regenerating areas. During the therapeutic application, MSCs are directly exposed to the reactive species of CAP. Therefore, the investigation of CAP-induced effects on MSCs is essential. In this study, we quantified the amount of ROS due to the CAP activation of the culture medium. In addition, cell number, metabolic activity, stress signals, and migration were analyzed after the treatment of MSCs with a CAP-activated medium. CAP-activated media induced a significant increase in ROS but did not cause cytotoxic effects on MSCs when the treatment was singular and short-term (one day). This single treatment led to increased cell migration, an essential process in wound healing. In parallel, there was an increase in various cell stress proteins, indicating an adaptation to oxidative stress. Repeated treatments with the CAP-activated medium impaired the viability of the MSCs. The results shown here provide information on the influence of treatment frequency and intensity, which could be necessary for the therapeutic application of CAP.

Comprehensive studies on the biological activities of human metastatic (MDA-MB-231) and non-metastatic (MCF-7) breast cancer cell lines, directly or combinedly treated using non-thermal plasma-based approaches.

Progressive incidence and a pessimistic survival rate of breast cancer in women worldwide remains one of the most concerning topics. Progressing research indicates a potentially high effectiveness of use cold atmospheric plasma (CAP) systems. The undoubted advantage seems its simplicity in combination with other anti-cancer modalities. Following observed trend of studies, one inventory CAP system was applied to directly treat human breast cancer cell lines and culturing in two different Plasma Activated Media (PAM) for combined utilization. Proposed CAP treatments on MCF-10 A, MCF-7, and MDA-MB-231 cell lines were studied in terms of impact on cell viability by MTT assay. Disturbances in cell motility following direct and combined CAP application were assessed by scratch test. Finally, the induction of apoptosis and necrosis was verified with annexin V and propidium iodide staining. Reactive species generated during CAP treatment were determined based on optical emission spectrometry analysis along with colorimetric methods to qualitatively assess the NO2-, NO3-, H2O2, and total ROS with free radicals concentration. The most effective approach for CAP utilization was combined treatment, leading to significant disruption in cell viability, motility and mostly apoptosis induction in breast cancer cell lines. Determined CAP dose allows for mild outcome, showing insignificant harm for the non-cancerous MCF-10 A cell line, while the highly aggressive MDA-MB-231 cell line shows the highest sensitivity on proposed CAP treatment. Direct CAP treatment seems to drive the cells into the sensitive state in which the effectiveness of PAM is boosted. Observed anti-cancer response of CAP treatment was mostly triggered by RNS (mostly NO2- ions) and ROS along with free radicals (such as H2O2, OH•, O2-•, 1O2, HO2•). The combined application of one CAP source represent a promising alternative in the development of new and effective modalities for breast cancer treatment.

Effect of atmospheric pressure plasma jet on the structure and physicochemical properties of wheat starch.

The effect of atmospheric pressure plasma jet (APPJ) with different discharge power (0, 400, 600, and 800 W) on the structure and physicochemical properties of wheat starch were evaluated in this study. After APPJ treatments, significant declines in peak viscosity, breakdown viscosity, and final viscosity of wheat starch pasting parameters were observed with increase of plasma treatment power. Being treated with discharge power of 800 W, the PV and BD value of wheat starch paste significantly dropped to 2,578 and 331 cP, respectively. Apparently, APPJ could raise the solubility of wheat starch, while reduce the swelling capacity, and also lower the G' and G″ value of wheat starch gel. Roughness and apparent scratch was observed on the surface of the treated wheat starch granules. Although APPJ treatment did not alter wheat starch's crystallization type, it abated the relative crystallinity. APPJ treatment might be useful in producing modified wheat starch with lower viscosity and higher solubility.