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A continuous risk from microbial infections poses a major environmental and public health challenge. As an emerging strategy for inhibiting bacterial infections, plasma‐activated water (PAW) has proved to be highly effective, environmental‐friendly, and non‐drug resistant to a broad range of microorganisms. However, the relatively short lifetime of reactive oxygen and nitrogen species (RONS) and the high spreadability of liquid PAW inevitably limit its real‐life applications. In this study, plasma‐activated hydrogel (PAH) is developed to act as reactive species carrier that allow good storage and controlled slow‐release of RONS to achieve long‐term antibacterial effects. Three hydrogel materials, including hydroxyethyl cellulose (HEC), carbomer 940 (Carbomer), and acryloyldimethylammonium taurate/VP copolymer (AVC) are selected, and their antibacterial performances under different plasma activation conditions are investigated. It is shown that the composition of the gels plays the key role in determining their biochemical functions after the plasma activation. The antimicrobial performance of AVC is much better than that of PAW and the other two hydrogels, along with the excellent stability to maintain the antimicrobial activity for more than 14 days. The revealed mechanism of the antibacterial ability of the PAH identifies the unique combination of short‐lived species (1O2, ∙OH, ONOO− and O2−) stored in hydrogels. Overall, this study demonstrates the efficacy and reveals the mechanisms of the PAH as an effective and long‐term disinfectant capable of delivering and preserving antibacterial chemistries for biomedical applications. [ABSTRACT FROM AUTHOR]

Enhancing virus multiplication could assist in the rapid production of vaccines against viral diseases. Cold atmospheric plasma (CAP), a physical approach relying on reactive oxygen species to achieve the desirable cellular outcome, was shown to be effective in enhancing virus propagation, where bovine rhinotrachieitis virus and Madin-Darby Bovine Kidney cells were used as the modeling virus and cell line, respectively. CAP was shown to create synergies with virus infection in arresting host cells at the G2/M stage, decreasing cell membrane potential, increasing intracellular calcium level, and inducing selective autophagy. In addition, CAP was demonstrated to suppress virus-triggered immunogenic signaling as evaluated by IRF7 expression. We presented evidences on CAP-triggered maximization of host resources toward virus multiplication that is advantageous for viral vaccine production, and opened a novel regime for applying CAP in the sector of medical care and health. [ABSTRACT FROM AUTHOR]

[Display omitted] • Underwater plasma bubbles were used to degrade cefixime in water. • Complete cefixime degradation with high-energy yield of 1.5 g/kWh. • Degradation of cefixime was conducted by reactive species, especially short-lived OH radicals. • Degradation pathways of cefixime were proposed by intermediates identified by LCMS. • Plasma treatment leads to the loss of antibacterial activity and cytotoxicity of cefixime. Excessive use and indiscriminate discharge of antibiotics inevitably lead to their accumulation in the environment, posing significant ecological and physiological risks. Non-thermal plasma (NTP) is receiving increasing attention as a sustainable technology for the efficient breakdown of these antibiotics as well as other contaminants. However, implementation of NTP technology still faces several hurdles, particularly the maximization of the reactive plasma effects and the practical scaling approaches. In this study, we generated NTP inside forming bubbles with enlarged gas-liquid interfacial areas for efficient delivery of reactive plasma species to target cefixime antibiotic molecules in aqueous solution. The degradation of cefixime was largely dependent on the different number of microholes, air flow rate, discharge power, plasma exposure time and solution properties. Results show that a high-performance degradation was achieved in the 10-microhole reactor with an energy yield of 1.5 g/kWh, after 30 min of plasma treatment. Based on LC-MS analysis, an NTP-initiated cefixime degradation pathway was proposed. Cytotoxicity studies demonstrated that the antibiotic activity of cefixime was effectively and wholly deactivated by the plasma process, and that no toxic effects of the 30 min-treated water were observed toward human cell lines. Furthermore, considering that air was employed as the inducer gas, which results in the formation of reactive nitrogen species in the water, the treated water was able to enhance seedling growth, further contributing to the societal and economic benefits of this plasma-based antibiotic degradation strategy. [ABSTRACT FROM AUTHOR]

Simple Summary: Cold atmospheric plasma (CAP) and plasma-activated medium (PAM) are known to selectively kill cancer cells, however the efficacy of CAP in cancer cells following epithelial-mesenchymal transition (EMT), a process which endows cancer cells with increased stemness, metastatic potential, and resistance to conventional therapies, has not been previously examined. We have used several established models of EMT to show that PAM is significantly more active in cancer cells exhibiting EMT than their epithelial counterparts. We further show that this enhancement correlated with increased levels of reactive oxygen species (ROS) in the mesenchymally-shifted cell lines. Cold atmospheric plasma (CAP) has emerged as a highly selective anticancer agent, most recently in the form of plasma-activated medium (PAM). Since epithelial–mesenchymal transition (EMT) has been implicated in resistance to various cancer therapies, we assessed whether EMT status is associated with PAM response. Mesenchymal breast cancer cell lines, as well as the mesenchymal variant in an isogenic EMT/MET human breast cancer cell system (PMC42-ET/LA), were more sensitive to PAM treatment than their epithelial counterparts, contrary to their responses to other therapies. The same trend was seen in luminal muscle-invasive bladder cancer model (TSU-Pr1/B1/B2) and the non-muscle-invasive basal 5637 bladder cancer cell line. Three-dimensional spheroid cultures of the bladder cancer cell lines were less sensitive to the PAM treatment compared to their two-dimensional counterparts; however, incrementally better responses were again seen in more mesenchymally-shifted cell lines. This study provides evidence that PAM preferentially inhibits mesenchymally-shifted carcinoma cells, which have been associated with resistance to other therapies. Thus, PAM may represent a novel treatment that can selectively inhibit triple-negative breast cancers and a subset of aggressive bladder cancers, which tend to be more mesenchymal. Our approach may potentially be utilized for other aggressive cancers exhibiting EMT and opens new opportunities for CAP and PAM as a promising new onco-therapy. [ABSTRACT FROM AUTHOR]

• Underwater plasma bubbles facilitated mass transfer of highly reactive species. • Plasma catalytic bubbles using CeO 2 enhanced the AP removal efficiency. • Catalytic performance and durability of CeO 2 were improved by plasma activation. • Degradation mechanisms of AP were proposed by intermediates identified by LCMS. Interactions between effects generated by non-thermal plasma (NTP) and catalysts are increasingly investigated, ranging from energy conversion and material synthesis to pollutant degradation (e.g. volatile organic compounds, VOCs) and water purification. To make the water ecosystem more environmentally and economically sustainable, green and efficient wastewater treatment technologies are urgently required. In this study, a plasmacatalytic bubble column reactor was designed to generate underwater plasma bubbles (PBs) for efficient delivery of plasma-produced gaseous reactive oxidative species to the liquid phase for subsequent applications. This system shows great potential for degrading a stubborn water contaminant azophloxine (AP), which was further enhanced with an addition of CeO 2 catalysts, resulting in the catalytic oxidation of the azo dyes. Moreover, the performances and durability of CeO 2 were further improved via plasma pre-activation. The plasma-treated CeO 2 (CeO 2 -P) displayed a combination of favourable properties, such as a higher concentration of oxygen vacancies and Ce3+ (observed by XPS), a narrowed energy bandgap, and an increased specific surface area (by 41.39%). Compared with the sole PBs and PBs/CeO 2 systems, the highest removal efficiency and kinetic constant up to 99.5% and 0.907 min−1, respectively, were achieved in the PBs/CeO 2 -P system. Reactive species trapping corroborated that ·OH and ·O 2 – played an integral part in AP degradation. Finally, intermediates in the process of AP degradation were identified and a degradation pathway was proposed. This research would offer a promising remediation methodology for water purification via the integration of underwater plasma bubbles and CeO 2 catalysts. [ABSTRACT FROM AUTHOR]