Cold Atmospheric Plasma Treatment Research Articles

Biomedical Applications of Cold Atmospheric Plasma: Cancer Therapy and Virus Inactivation

Cold atmospheric plasma (CAP), known for its ability to generate Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS), has emerged as a promising tool in many biomedical applications, including cancer therapeutics and virus inactivation. In cancer therapy, ROS and RNS induced by plasma have been shown to selectively target cancer cells, triggering apoptosis and inhibiting tumor growth while sparing healthy cells. This selective cytotoxicity makes plasma an attractive option for localized cancer treatment with minimal side effects. Additionally, the antimicrobial properties of ROS and RNS make plasma an effective agent for virus inactivation. By connecting the dots between cancer therapy and virus disinfection, this review paper sheds light on the potential of plasma-generated ROS and RNS as versatile tools in medical applications, offering a dual benefit of targeted cancer treatment and effective virus control. Specifically, this review explores the effects of CAP treatment on B16 melanoma cells, assessing changes in cell viability, proliferation, apoptosis and oxidative stress response. Dichloroacetate (DCA), a mitochondrial modulator, has shown promise in inducing apoptosis in melanoma cells. However, its clinical use is limited by side effects related to its neurotoxicity and suspected carcinogenicity. The potential of CAP in enhancing the therapeutic efficacy of DCA on B16-F10 melanoma apoptosis is also explored. CAP therapeutics for other types of cancers are also explored in this review. Alongside its implications in oncology, CAP has gathered substantial attention for its extraordinary potential in neutralizing viruses. CAP’s exceptional precision in targeting viral envelopes, genetic material and structural components disrupts their integrity and vital functions. This orchestrated mechanism offers a swift and efficacious route to render viruses inactive, encompassing both enveloped and nonenveloped viral types. In parallel pursuit, this review examines CAP-generated reactive species’ proficiency in deactivating SARS-CoV-2 across various surfaces. The inquiry entails subjecting surfaces to CAP treatment, succeeded by quantifying viral load and scrutinizing viral integrity. The outcomes gleaned from these investigations provide pivotal insights into CAP’s potential as a robust surface disinfection strategy, poised to combat the propagation of viral transmission.

Emerging Alternaria toxins present in naturally contaminated dried tomatoes and their reduction using cold atmospheric plasma

This study investigated the efficacy of cold atmospheric plasma (CAP) treatment in degrading the emerging Alternaria toxins as pure molecules and as natural contaminants in dried tomatoes. The analyses of 25 batches of dried tomatoes showed that more than 40% of samples were contaminated with tenuazonic acid (TeA), one with Alternariol (AOH), while Tentoxin (TEN), Alternariol monomethyl ether (AME) and Altenuene (ALT) were not detected. CAP under ozone (O3) and NOx regimes were used to reduce the mycotoxin contamination, the results shown that O3 regime was more effective against all mycotoxins tested, while NOx regime showed different efficacy depending on the specific mycotoxin. The Weibull model proved to be appropriate for the degradation kinetics of all Alternaria toxins, regardless of the kinetic order they possess. Under the O3 regime, the resistance of the mycotoxin was AME > AOH > TEN > TeA > ALT. Our studies have shown for the first time that CAP reduces Alternaria toxins in naturally contaminated dried tomatoes. In particular, the rate of degradation under O3 regime increased significantly with the longest exposure time, reaching 52.80 ± 1.21 % of mycotoxin degradation. Our results expand our knowledge of CAP treatment as a potential means of reducing mycotoxin contamination in food. Further studies will be carried out to investigate the potential mycotoxin degradation products and to ensure food safety.

Influence of Biofilm Maturity on the Antibacterial Efficacy of Cold Atmospheric Plasma in Oral Microcosm Biofilms

As biofilms mature, biomass and extracellular polysaccharide (EPS) content increases, enhancing pathogenicity. Therefore, this study aimed to evaluate the antibacterial efficacy of cold atmospheric plasma (CAP) against oral microcosm biofilms and the influence of biofilm maturity on treatment. Oral microcosm biofilms were cultured on hydroxyapatite disks for 2 and 6 days. Based on the treatment and biofilm maturity, these were subsequently allocated into six groups (N = 19 each): Groups 1 and 2 were incubated with distilled water for 1 min; Groups 3 and 4 were treated with CAP for 2 min, and Groups 5 and 6 were treated with 0.12% chlorhexidine gluconate for 1 min. Groups 1, 3, and 5 represent 2-day biofilms, and Groups 2, 4, and 6 represent 6-day biofilms. Treatments were repeated daily for 5 days. Antibacterial efficacy was analyzed by measuring oral biofilms’ red fluorescence intensity (RatioR/G) and quantifying EPS content and bacterial viability. The RatioR/G was 1.089-fold and 1.104-fold higher in Groups 4 and 6 than in Groups 3 and 5 following antibacterial treatment, respectively (p < 0.001). EPS content increased by 1.71-fold in Group 6 than in Group 5 (p < 0.001). Bacterial survival rate was the lowest in Group 3 (p = 0.005). These findings underscore the relevance of CAP treatment in maintaining antibacterial efficacy regardless of the biofilm development stage, highlighting its potential utility in oral care.

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.

Improved wound healing by direct cold atmospheric plasma once or twice a week: a randomized controlled trial on chronic venous leg ulcers.

This study compared the effect of two frequencies of direct cold atmospheric plasma (direct-CAP) treatment with standard of care (SOC) alone on healing of venous leg ulcers (VLUs). Open-label, randomized controlled trial (ClinicalTrials.gov: NCT04922463) on chronic VLUs at two home care organizations in the Netherlands. All three groups received SOC for 12 weeks or until healing. Additionally, treatment groups received direct-CAP once (1x direct-CAP) or twice (2x direct-CAP) a week, at specialized wound care facilities and the patients' residences. Primary outcome was percentage of wounds healed. Secondary outcomes included wound area reduction and adverse events. 46 patients were randomly allocated to receive SOC only (n=15), SOC + direct-CAP once a week (n=17) or SOC + direct-CAP twice a week (n=14). A higher percentage of wounds healed within 12 weeks in the treatment groups: 53.3% (1x direct-CAP, p=0.16) and 61.5% (2x direct-CAP, p=0.08) vs 25.0% (control). The largest wound area reduction was obtained with 2x direct-CAP (95.2%, p=0.07), followed by 1x direct-CAP (63.9%, p=0.58), vs control (52.8%). Absolute wound area reduced significantly compared with baseline in both treatment groups (p≤0.001), not in control (p=0.11). No device-related serious adverse events occurred. Direct-CAP applied once or twice a week could substantially improve wound healing of VLUs in primary care. Together with other clinical safety and efficacy data, these results support the integration of direct-CAP as a valuable therapy for complex wounds.

High-efficiency and low-damage modification of engineering metal materials by oxygen-mixing atmospheric pressure cold plasma jets

Engineering metal materials have been widely developed and applied in aviation, aerospace and biomedicine fields. Wettability improvement of these materials can alleviate problems caused by low adhesion and poor bioactivity, thereby facilitating their practical applications. Compared with other methods, atmospheric pressure cold plasma treatment has better versatility and can efficiently improve wettability without causing serious damages, and has therefore been widely used in polymer hydrophilization. However, when treating metal materials, the cold plasma may induce surface breakdown or have low efficiency. In this paper, we developed a new cold plasma jet by mixing oxygen into working gas to achieve high-efficiency and low-damage modification. When oxygen mixing ratio was 0.4 %, the cold plasma jet could modify TC4 titanium alloy surface to be superhydrophilic within 20 s, which was much more efficient than traditional plasma jet (120 s). We then further investigated the mechanism contributing to higher efficiency, and found that the oxygen-mixing plasma jet did not cause serious damages, while generating more polar groups by higher-concentration active particles, as confirmed by surface energy calculation and optical emission spectra. Besides titanium alloy, the oxygen-mixing plasma jet could also achieve rapid hydrophilization of various engineering metal materials, showing promising application prospects.

Unveiling the interaction mechanisms of cold atmospheric plasma and amino acids by machine learning

AbstractPlasma medicine has attracted tremendous interest in a variety of medical conditions, ranging from wound healing to antimicrobial applications, even in cancer treatment, through the interactions of cold atmospheric plasma (CAP) and various biological tissues directly or indirectly. The underlying mechanisms of CAP treatment are still poorly understood although the oxidative effects of CAP with amino acids, peptides, and proteins have been explored experimentally. In this study, machine learning (ML) technology is introduced to efficiently unveil the interaction mechanisms of amino acids and reactive oxygen species (ROS) in seconds based on the data obtained from the reactive molecular dynamics (MD) simulations, which are performed to probe the interaction of five types of amino acids with various ROS on the timescale of hundreds of picoseconds but with the huge computational load of several days. The oxidative reactions typically start with H‐abstraction, and the details of the breaking and formation of chemical bonds are revealed; the modification types, such as nitrosylation, hydroxylation, and carbonylation, can be observed. The dose effects of ROS are also investigated by varying the number of ROS in the simulation box, indicating agreement with the experimental observation. To overcome the limits of timescales and the size of molecular systems in reactive MD simulations, a deep neural network (DNN) with five hidden layers is constructed according to the reaction data and employed to predict the type of oxidative modification and the probability of occurrence only in seconds as the dose of ROS varies. The well‐trained DNN can effectively and accurately predict the oxidative processes and productions, which greatly improves the computational efficiency by almost ten orders of magnitude compared with the reactive MD simulation. This study shows the great potential of ML technology to efficiently unveil the underpinning mechanisms in plasma medicine based on the data from reactive MD simulations or experimental measurements.

Cold atmospheric plasma attenuates skin cancer via ROS induced apoptosis.

Cold atmospheric plasma (CAP) has been widely used in biomedical research, especially in vitro cancer therapy. Cutaneous squamous cell carcinoma (CSCC) is a malignant tumor originating from epidermal keratinocytes. However, the mechanism of CAP therapy on CSCC remains unclear. The animal models of CSCC induced by 7,12-dimethylbenz(a) anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA) were constructed. For the CAP treatment group, after each TPA application, CAP was administered for 3min twice weekly after drying. HE staining were used to detect the pathological status of tumor tissue in each group. The levels of PCNA, Bcl-2, Bax, MMP2 and MMP9 were evaluated by western blot and qPCR. TUNEL staining were used to detect apoptosis in tumor tissues. In vivo, serum samples were used for ELISA of total ROS. MTT assay was used to detect the viability of A431 cells. Western blot and qPCR were used to detect the levels of PCNA, Bcl-2, Bax, MMP2 and MMP9 in A431 cells. A431 cell proliferation was examined by colony formation assay. The proportions of apoptosis of A431 cells were detected by flow cytometry. Transwell assessed the ability of A431 cells migration and proliferation. We found that CAP could induce skin cancer cells apoptosis and inhibit the progress of skin cancer. Through experiments in vitro, reactive oxygen species (ROS) generated by N-acetylcysteine (NAC) and CAP inhibited the proliferation and migration of A431 skin cancer cells while promoting apoptosis. These evidences suggest the protective effect of CAP in CSCC, and CAP has the potential clinical application of CSCC.

Cold Plasma Treatment of Little Millet Flour: Impact on Bioactives, Antinutritional Factors and Functional Properties.

This study delves into the transformative effects of atmospheric cold plasma (CP) treatment on little millet flour (LMF), specifically exploring alterations in bioactive compounds, antinutritional factors, and functional properties. Foaming and emulsification properties experienced noteworthy enhancements with plasma treatment, manifesting in significant increases in foaming capacity (up to 51.47 ± 0.49%), foaming stability, emulsification ability, and emulsion stability (up to 47.02 ± 0.35%). The treatment also positively influenced water absorption index and swelling power. Antinutritional factors, including tannins and saponins, exhibited substantial reductions following plasma treatment. Saponin content, for instance, decreased by an impressive 58% after exposure to 20kV for 20min. Conversely, bioactive compounds such as phenolic content and antioxidant activity saw significant increases. Total phenolic content (TPC) rose from 527.54 ± 8.94 to 575.82 ± 3.58mg GAE/100g, accompanied by a remarkable 59% boost in antioxidant activity. Interestingly, plasma treatment did not exhibit a discernible effect on pasting properties. These findings collectively underscore the potential of atmospheric CP treatment as a novel and effective method for enhancing the functional and nutritional attributes of LMF, thereby opening new avenues for its application in food science and technology.

Effect of (multi pin) atmospheric cold plasma treatment on curcumin extraction and investigating phytochemicals, antioxidants, physical and morphological properties of turmeric (Curcuma longa L.) powder

This investigation was focused on the impact of cold plasma (CP) on the extraction of curcumin and bioactive compounds of turmeric powder (TP). TP was treated with CP at different applied voltages (10, 20, and 30 kV), with various exposure times (10, 20, and 30 min). The curcumin content was highest at 30 kV for 10 min with a yield of 46.49 mg/g of TP. Total phenols significantly (p < 0.05) enhanced from 163.91 to 360.78 mg GAE/g DW accompanied by a remarkable 16% increment in total flavonoids, paralleled by a 26% increment in antioxidants as of control. Nuclear magnetic resonance spectra justified the extraction of curcuminoids. Moreover, micrographs displayed cell lysis in the treated powder. CP has exhibited a positive effect on surface colour parameters and thermal properties of TP. Overall, CP technology can be tailored for better curcumin extraction and the enhancement of phytochemicals.

Application of atmospheric cold plasma for zearalenone detoxification in cereals: Kinetics, mechanisms, and cytotoxicity analysis

IntroductionZearalenone (ZEN) is one of the most widely contaminated mycotoxins in world, posing a severe threat to human and animal health. Atmospheric cold plasma (ACP) holds great penitential in mycotoxin degradation. ObjectivesThis study aimed to investigate the degradation efficiency and mechanisms of ACP on ZEN as well as the cytotoxicity of ZEN degradation products by ACP. Additionally, this study also investigated the degradation efficiency of ACP on ZEN in cereals and its effect on cereal quality. MethodsThe degradation efficiency and products of ZEN by ACP was analyzed by HPLC and LC-MS/MS. The human normal liver cells and mice were employed to assess the cytotoxicity of ZEN degradation products. The ZEN artificially contaminated cereals were used to evaluate the feasibility of ACP detoxification in cereals. ResultsThe results showed that the degradation rate of ZEN was 96.18 % after 30-W ACP treatment for 180 s. The degradation rate was dependent on the discharge power, and treatment time and distance. Four major ZEN degradation products were produced after ACP treatment due to the oxidative destruction of CC double bond, namely C18H22O7 (m/z = 351.19), C18H22O8 (m/z = 367.14), C18H22O6 (m/z = 335.14), and C17H20O6 (m/z = 321.19). L02 cell viability was increased from 52.4 % to 99.76 % with ACP treatment time ranging from 0 to 180 s. Mice results showed significant recovery of body weight and depth of colonic crypts as well as mitigation of glomerular and liver damage. Additionally, ACP removed up to 50.55 % and 58.07 % of ZEN from wheat and corn. ConclusionsThis study demonstrates that ACP could efficiently degrade ZEN in cereals and its cytotoxicity was significantly reduced. Therefore, ACP is a promising effective method for ZEN detoxification in cereals to ensure human and animal health. Future study needs to develop large-scale ACP device with high degradation efficiency.

Atmospheric cold plasma-induced mortality in Sitophilus oryzae (L.)

The rice weevil, Sitophilus oryzae, is a common pest in grain storage and agriculture, causing considerable damage to stored grains. Increasing resistance of rice weevils to current fumigation methods continues to occur, necessitating the development of alternative control strategies. In this study, we investigated the impact of atmospheric cold plasma (ACP) on the mortality of rice weevils. ACP generates non-thermal ionized gas at or near room temperature and has been effective in inactivating microorganisms and pests, including rice weevils. We hypothesized that ACP treatment would have detrimental effects on the weevils, leading to a high mortality rate. To evaluate this hypothesis, we applied a treatment voltage of 80 kV and treatment times of 0, 3, 5, 8, and 10 min across all life stages of rice weevils, including the egg, larval (1st – 4th instars), pupal, and adult phases. Additionally, we examined post-treatment retention times of 0, 24, 48, and 72 h to assess how long the treated weevils survived after exposure. We observed that both treatment time and post-treatment retention time impacted, especially for weevils treated with shorter durations. Higher treatment times (5,8, and 10 min) showed that eggs failed to hatch, larvae and pupae were unable to emerge, and adults either died immediately after treatment (depending on the treatment duration) or within 24–48 h post-treatment. Based on these findings, we can conclude that ACP has detrimental effects on rice weevils, providing valuable insights into the potential use of ACP as an integrated pest management strategy.

Assessing the Effects of Cold Atmospheric Plasma on the Natural Microbiota and Quality of Pork during Storage.

Cold atmospheric plasma (CAP) is a novel non-thermal technology with significant potential for use in meat processing to prolong shelf life. The objective of the study was to evaluate the efficiency of CAP treatment on the natural microbiota and quality traits of pork stored for 8 days at 4 °C. CAP treatment was applied by employing piezoelectric direct discharge technology to treat pork samples for 0, 3, 6, and 9 min. Reductions of approximately 0.8-1.7 log CFU/g were observed in total viable counts (TVC) and Pseudomonas spp. levels for CAP treatments longer than 3 min, immediately after treatment. A storage study revealed that CAP-treated pork (>6 min) had significantly lower levels of TVC, Pseudomonas spp., and Enterobacteriaceae throughout storage. Regarding quality traits, CAP application for longer than 3 min significantly increased water retention and yellowness and decreased meat redness compared to untreated pork. However, other parameters such as pH, tenderness, and lightness exhibited no statistically significant differences between untreated and CAP-treated pork. Lipid oxidation levels were higher only for the 9-min treatment compared to untreated pork. Our results revealed that CAP is a promising technology that can extend the microbiological shelf life of pork during refrigeration storage.

Pathogens inactivation and preservation of Pacific white shrimp by atmospheric cold plasma treatment

Atmospheric cold plasma (ACP) efficacy in inactivating Listeria monocytogenes and Vibrio parahaemolyticus was investigated on fresh and frozen shrimp. ACP inactivation efficacy increased with treatment time (5–20 min) and treatment voltages (60–80 kV) due to increased reactive gas species. ACP yielded stronger pathogen inactivation on frozen versus fresh shrimp. ACP treatment at 80 kV for 30 min maximally reduced L. monocytogenes and V. parahaemolyticus by 0.94 and 1.26 log CFU/g on fresh shrimp and by 1.68 and 2.0 log CFU/g on frozen shrimp. During storage at 4 °C, ACP-treated shrimp exhibited slightly higher thiobarbituric acid reactive substances (TBARS) levels but overall improved quality attributes, including lower total viable count, total volatile basic nitrogen, and pH, as well as higher sensory scores compared to the controls. ACP also extended shrimp shelf-life by 2 days. Therefore, ACP holds significant potential for seafood disinfection and preservation. Industrial relevanceACP effectively reduced levels of Listeria monocytogenes and Vibrio parahaemolyticus on both fresh and frozen shrimp with greater inactivation effects on frozen shrimp. In addition to enhancing microbial safety, ACP also improved shrimp quality and extended shelf-life. ACP could readily be coupled with packaging technology and bio preservatives to enhance its efficacy. This research provides a foundation for the eventual industrial adoption of ACP technology to benefit both consumers through reduced pathogen risks, and seafood processors through improved product safety, quality, and shelf-life.

Decitabine combined with cold atmospheric plasma induces pyroptosis via the ROS/Caspase-3/GSDME signaling pathway in Ovcar5 cells

BackgroundHigh methylation of the DFNA5 gene results in the absence of GSDME, a key protein that mediates pyroptosis, while decitabine demethylates the DFNA5 gene, resulting in high expression of the GSDME protein. Cold atmospheric plasma (CAP) is a novel anti-cancer method that induces tumor cell death. MethodsThe pyroptosis induced by decitabine in combination with CAP in Ovcar5 cells was evaluated. In particular, mitochondrial membrane potential was estimated by JC-1 staining, dehydrogenase (LDH) release was assessed by ELISA, Annexin V/PI staining was detected by flow cytometry, the cell cycle changes were evaluated using PI staining followed by detection by flow cytometry, and Caspase-9 cleavage, Caspase-3 cleavage and GSDME expression were evaluated by western blot. ResultsDecitabine resulted in high expression of the GSDME in Ovcar5 in a concentration-dependent manner and increased tumor cell sensitivity to CAP. CAP induced mitochondrial damage and activated the Caspase-9/Caspase-3 pathway. Therefore, decitabine combined with CAP induced Ovcar5 cell pyroptosis through Caspase-3 mediated GSDME cleavage. Reactive oxygen species (ROS) generated by CAP treatment played an important role in the CAP/decitabine combination-induced production of ROS, activation of Caspase-9/Caspase-3, GSDME cleavage and pyroptosis that ROS scavenger NAC inhibited all these processes. ConclusionsCAP combined with decitabine induced Caspase-3 activation, which cleaved decitabine-upregulated GSDME and ediated pyroptosis.

Cold Atmospheric Plasma Improves the Colonization of Titanium with Primary Human Osteoblasts: An In Vitro Study.

Several studies have shown that cold atmospheric plasma (CAP) treatment can favourably modify titanium surfaces to promote osteoblast colonization. The aim of this study was to investigate the initial attachment of primary human osteoblasts to plasma-treated titanium. Micro-structured titanium discs were treated with cold atmospheric plasma followed by the application of primary human osteoblasts. The microwave plasma source used in this study uses helium as a carrier gas and was developed at the Leibniz Institute for Surface Modification in Leipzig, Germany. Primary human osteoblasts were analyzed by fluorescence and cell biological tests (alkaline phosphatase activity and cell proliferation using WST-1 assay). The tests were performed after 4, 12, and 24 h and showed statistically significant increased levels of cell activity after plasma treatment. The results of this study indicate that plasma treatment improves the initial attachment of primary human osteoblasts to titanium. For the first time, the positive effect of cold atmospheric plasma treatment of micro-structured titanium on the initial colonization with primary human osteoblasts has been demonstrated. Overall, this study demonstrates the excellent biocompatibility of micro-structured titanium. The results of this study support efforts to use cold atmospheric plasmas in implantology, both for preimplantation conditioning and for regeneration of lost attachment due to peri-implantitis.

Inactivation of lipase and lipoxygenase in whole wheat flour using atmospheric cold plasma and steam treatments: Kinetics, mechanism, and impact on its compositional properties

This study aims to utilize two separate techniques, viz., atmospheric cold plasma (voltage: 5–25 kV; time: 1–10 min) and steam treatments (at 100 °C for 1–4 min), to inactivate lipase and lipoxygenase in whole wheat flour (WWF) and assess the impact on its compositional properties. The cold plasma exposure of WWF at 25 kV/6 min resulted in 97.5% and 100% inactivation in lipase and lipoxygenase activity, respectively, whereas corresponding inactivation values after the steam treatment (100 °C/4 min) were 90.6% and 99.7%. The inactivation order (n) of lipase and lipoxygenase during cold plasma treatment was 1.2 and 1.0, respectively. In the optical emission spectra of cold plasma-induced air, the band heads within 328–426 nm confirmed the transition between various reactive nitrogen species (second positive, first negative, second positive, and mono-positive systems). The band-head for OH radicals was recorded at 314 nm. The oxygen molecular band at 739 nm and singlet oxygen transition line at 778 nm were also observed. The cold plasma and steam treatments resulted in a more random coil in lipase's secondary structure. The cold plasma treatment at 25 kV/6 min didn't impact the particle size, density, color profile, and proximate composition of the flour.

Integrated in-package treatment of hydrogen peroxide and cold plasma for microbial inactivation of cabbage slices.

The efficacy of an in-package microbial inactivation method, combining H2O2 and atmospheric dielectric barrier discharge cold plasma (ADCP) treatments (H2O2-ADCP), in reducing contamination of Brassica oleracea (cabbage) slices was investigated. Cabbage slices were placed in a polyethylene terephthalate container with a H2O2-soaked polypropylene pad attached to the inside of the lid, followed by subjecting the closed container to ADCP treatment. The H2O2-ADCP treatment inactivated Escherichia coli O157:H7 and Listeria monocytogenes, resulting in reductions of 1.8 and 2.0 log CFU/g, respectively, which were greater than the sum of the inactivation effects observed with each individual treatment. The combined treatment decreased the count of Bacillus cereus spores and indigenous bacteria by 1.0 log spores/g and 1.3 log CFU/g, respectively. Moreover, the in-package method did not alter the moisture content or texture of cabbage slices. These results demonstrate the potential of H2O2-ADCP as a microbial decontamination method for packaged cabbage slices.

Survival of Listeria Strains and Shelf Life Determination of Fresh Blueberries (Vaccinium corymbosum) Treated with Cold Atmospheric Plasma.

Fresh blueberries are delicate, hand-picked, packaged, and refrigerated fruits vulnerable to spoilage and contamination. Cold atmospheric plasma (CAP) is a promising antimicrobial technology; therefore, this study evaluated the CAP treatment effect on acid-tolerant Listeria innocua and Listeria monocytogenes and evaluated changes in the quality of the treated fruit. Samples were spot-inoculated with pH 5.5 and 6.0 acid-adapted Listeria species. Samples were treated with gliding arc CAP for 15, 30, 45, and 60 s and evaluated after 0, 1, 4, 7, and 11 days of storage at 4 °C and 90% humidity for the following quality parameters: total aerobic counts, yeast and molds, texture, color, soluble solids, pH, and titratable acidity. CAP treatments of 30 s and over demonstrated significant reductions in pathogens under both the resistant strain and pH conditions. Sixty-second CAP achieved a 0.54 Log CFU g-1 reduction in L. monocytogenes (pH 5.5) and 0.28 Log CFU g-1 for L. monocytogenes (pH 6.0). Yeast and mold counts on day 0 showed statistically significant reductions after 30, 45, and 60 s CAP with an average 2.34 Log CFU g-1 reduction when compared to non-CAP treated samples. Quality parameters did not show major significant differences among CAP treatments during shelf life. CAP is an effective antimicrobial treatment that does not significantly affect fruit quality.

Cold atmospheric plasma stabilizes mismatch repair for effective, uniform treatment of diverse colorectal cancer cell types

Mismatch Repair (MMR) mechanisms play a pivotal role in rectifying DNA replication errors and maintaining the stability of DNA microsatellite structure. Colorectal cancer (CRC) can be characterized into microsatellite stability (MSS) and microsatellite instability (MSI) subtypes based on the functionality of MMR. MSI CRC notably exhibits enhanced chemotherapy resistance, attributable to diminished MMR-related protein expression. Cold atmospheric plasma (CAP) has emerged as a promising treatment modality, demonstrating efficacy in inducing apoptosis in various cancer cells. However, the therapeutic impact of CAP on MSI colorectal cancer, and the underlying mechanisms remain elusive. In this study, we investigated the effects of CAP on MSI (MC38, HCT116, and LOVO) and MSS (CT26 and HT29) CRC cell lines. We are probing into the products of CAP treatment. Our findings indicate that CAP treatment induces comparable effects on apoptosis, reactive oxygen species (ROS), and reactive nitrogen species (RNS), as well as the expression of apoptosis-related proteins in both MSI and MSS cells. Mechanistically, CAP treatment led to an elevation in the expression of mismatch repair proteins (MLH1 and MSH2), particularly in MSI cells, which notably have been proven to facilitate the activation of apoptosis-related proteins. Collectively, our study reveals that CAP enhances apoptotic signaling and induces apoptosis in MSI colorectal cancer cells by upregulating the expression of MMR-related proteins, thereby reinforcing MMR stabilization.