Search

IntroductionPenicillium Digitatum (PD) and Penicillium italicum diseases pose significant economic challenes to citrus fruit production across the globe. The primary aim of this research is to investigate the synergistic effects of low concentrations of H2O2 solution combined with transient spark discharge plasma on the inactivation of PD. Additionally, assess the chemical and physical profaties. Ultimately, this approach can be presented as an eco-friendly solution for rinsing citrus fruits on an industrial scale.Materials and MethodsThe Penicillium digitatum (PD) isolate (ATCC 24692) was obtained from the Tehran Molecular Mycology Laboratory and cultured on Sabouraud Dextrose Agar medium at pH 5.6 and 27°C for 7 days. The initial concentration of spores in the solution was determined using a UV absorption spectrophotometer, set to 0.1 at a wavelenth of 420 nm, and the concentration of spores was approximately equivalent to 106 spores fa milliliter (Palou et al., 2002). In this study, the plasma reactor had a point-to-plane geometry. The high-voltage needle electrode was placed above a Petri dish filled with a microbial solution combined with H2O2, while the grounded electrode was immersed in the solution. The distance between the tip of the needle electrode and the surface of the solution was 15 mm. Solutions of 0.05%, 0.1% and 0.5%v/v H2O2 (35% soluble in water) were added to the microbial solution before plasma treatment. The final volume of the solution was 5 ml and exposure times were 2.5, 5, 10, and 15 minutes. The reactor was fed with an air flow of 2 l/min. A transient spark discharge was generated, characterized by a discharge voltage of approximately 18 kV, short durations of less than 100 ns, and high current pulses exceeding 1A, with a repetition frequency ranging from 0.5 to 10 kHz. After treatment, H2O2, NO2‾, and NO3‾ as the main long-lived species in plasma-activated solution are measured. Also, physical factors such as electrical conductivity and pH were measured. Data Analysis faformed using SAS 9.4 software. Results and DiscussionWith increasing plasma treatment time and H2O2 concentration, the log reduction increased across all treatments. The combination of 0.1 and 0.5% H2O2 solution with plasma resulted in complete inactivation of P. digitatum within just 15 minutes. In plasma-treated solutions, regarding chemical profaties, the concentrations of H2O2, NO2‾, and NO3‾ increased linearly with the treatment time. Furthermore, the electrical conductivity increased linearly, with a notable acceleration in the treated 0.5% H2O2 solution, reaching 373µS cm-1. Additionally, pH value dropped from an initial value of 6.95, using distilled water as a control, to a low of 2.14 for plasma treated with 0.5% H2O2 after 15 min of exposure.ConclusionThe combined treatment was more effective than the isolated use of hydrogen faoxide solution. H2O2 enhances the effectiveness of plsma sterilization without requiring additional power input. Consequently, the synergistic application of atmospheric pressure plasma and H2O2 proved to be a promising method for the inactivation of PD. The findings indicate that reactive oxygen species (ROS) significantly contribute to the inactivation of PD cells, as well as the concentration of H2O2. Finally, the combination of H2O2 solution at 0.1 and 0.5% with cold plasma presents an environmentally friendly method for sanitizing citrus fruits.Acknowledgment This work was supported by the Ferdowsi University of Mashhad [Grant number 48527]. The authors greatly appreciate the technical support from Mazandaran University in Iran, particularly from the Department of Atomic and Molecular Physics. [ABSTRACT FROM AUTHOR]

Reactive species (RS) are the key factors of plasma‐activated solutions (PAS) against cancer. However, the specific contribution of each RS in inducing cancer cell death remain unclear. Therefore, this study aimed to evaluate the anticancer potential and mechanism of plasma‐activated medium (PAM) and plasma‐activated phosphate buffer saline (PA‐PBS) in vitro using colorectal cancer cells HCT116. Results showed that PAM and PA‐PBS effectively inhibited the growth and proliferation of HCT116 cells, with PA‐PBS exhibiting greater potency. H2O2, intracellular reactive oxygen species, and pH (H+) were essential mediators of cell death, and ONOO− exhibited cytotoxicity only after reaching a specific concentration. Additionly, PAS induced cell death through the exogenous apoptotic pathway. [ABSTRACT FROM AUTHOR]

Background: Cold atmospheric plasma (CAP) is an effective treatment for various skin diseases. Plasma-activated solution (PAS) is an indirect method of CAP treatment that produces biological effects similar to those of direct treatment with plasma devices. The anticancer and bacteriostatic effects of PAS have been demonstrated in vitro experiments; however, on the basis of the lack of toxicological studies on PAS, its effects on living mammals when administered by subcutaneous injection is poorly known. Purpose: The purpose of this study was to evaluate the effects of PAS on local skin tissue cells, blood system, heart, liver, lungs, kidneys and other vital organs of the rat when injected subcutaneously. Methods: PAS was prepared by CAP irradiation of phosphate-buffered saline (PBS). PBS and different PBS groups (CAP irradiation for 1, 3, or 5 min) were injected subcutaneously once every 48 h. The rats were euthanized immediately after 10 cycles of therapy. Results: No adverse effects were observed during the entire period of the experiment. Histopathological examination of organs and tissues revealed no structural changes. Moreover, no obvious structural changes were observed in skin tissue. DNA damage and cancerous proliferative changes were not detected in skin tissue treated with PAS. Subsequently, RNA sequencing and western blotting were performed. The results showed that PAS increased the expression of growth factors like transforming growth factor beta (TGF-β) and vascular endothelial growth factor A (VEGFA). These results might be directly linked to the role of PAS in stimulating TGF-β receptor signaling pathway and angiogenesis. Conclusion: The results showed that multiple subcutaneous injections of PAS did not show significant toxic side effects on local skin tissues and some vital organs in rats, providing a scientific basis to support the future treatment of skin diseases with PAS.

Cancer therapy consists of multidisciplinary treatment combining surgery, chemotherapy, radiotherapy, and immunotherapy. Despite the elucidation of cancer mechanisms by comprehensive genomic and epigenomic analyses and the development of molecular therapy, drug resistance and severe side effects have presented challenges to the long-awaited development of new therapies. With the rapid technological advances in the last decade, there are now reports concerning potential applications of non-equilibrium atmospheric pressure plasma (NEAPP) in cancer therapy. Two approaches have been tried: direct irradiation with NEAPP (direct plasma) and the administration of a liquid (e.g. culture medium, saline, Ringer's lactate) activated by NEAPP (plasma-activated solutions: PAS). Direct plasma is a unique treatment method in which various active species, charged ions, and photons are delivered to the affected area, but the direct plasma approach has physical limitations related to the device used, such as a limited depth of reach and limited irradiation area. PAS is a liquid that contains reactive oxygen species generated by PAS, and it has been confirmed to have antitumor activity that functions in the same manner as direct plasma. This review introduces recent studies of PAS and informs researchers about the potential of PAS for cancer therapy. Potential applications of plasma-activated solutions (PAS) in cancer therapy are described. Plasma-activated species generated in PAS, its effect on tumor cells, contribution to nonmalignant immune cells, selectivity and safety are presented. The proposed anti-tumor mechanisms of PAS to date are described. Efficacy and safety evaluations of PAS have been studied in experimental animal models, but no human studies have been conducted. [ABSTRACT FROM AUTHOR]

In this study, tilapia fillets were treated with the plasma-activated solution and refrigerated at 4 ± 1 °C. Compared with the distilled water group, plasma-activated lactic acid (PALA) treatment prolonged the microbiological shelf life of fish fillets by 4 d. The total bacterial count, psychrophilic bacteria, Pseudomonas spp., H 2 S-producing bacteria, and lactic acid bacteria in the PALA group were lower than those in the other treatment groups (P < 0.05). High-throughput sequencing indicated that Proteobacteria and Firmicutes were the two predominant core microbial phyla present during storage. In the first 5 d of storage, Acinetobacter , Kurthia, and Shewanella were the dominant genera. At the 7th d of storage, the spoilage bacteria Aeromonas and Pseudomonas increased slightly. These mechanistic results demonstrate that cold plasma solution treatment allows tilapia fillets to be stored under refrigeration for up to 7 d. Cold plasma solutions have potential applications in fish fillet refrigeration. • Plasma activated solution extended the refrigeration shelf life of fillets. • Plasma activated solution reduces microbial diversity. • Plasma activated solution can be used as a fish fillet disinfectant. [ABSTRACT FROM AUTHOR]

Melanoma is a common malignant skin tumor with highly invasive features and a high metastasis rate that can be difficult to treat clinically. Large-scale resection of primary cutaneous melanoma is often used to avoid postoperative recurrence. For advanced patients, radiotherapy, targeted therapy and immunotherapy are often needed. Low-temperature plasma has been proved to have significant antitumor effects on a variety of cancer cell lines cultured in vitro . The main limitation of direct low-temperature plasma treatment is that it has weak penetration ability and can only treat superficial lesions. In recent years, research on low-temperature plasma-activated solution has revealed that it also have good antitumor effects and low-temperature plasma penetration depth problems can be solved by local injection. The present study revealed that low-temperature plasma-activated phosphate buffer solution exhibited good antitumor effects and biosafety against melanoma in vitro and in vivo . It demonstrated that low-temperature plasma-activated solution has antitumor effects due to its regulation of intracellular redox, destruction of mitochondrial function and DNA damage. In vivo experiments demonstrated that treatment with low-temperature plasma-activated solution not only exhibited antitumor effects but also caused no significant damage to hematopoietic function or liver and kidney functions in mice. All these results demonstrated that low-temperature plasma-activated solution represent a promising antitumor treatment strategy., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 Yang et al.)

Melanoma is a common malignant skin tumor with highly invasive features and a high metastasis rate that can be difficult to treat clinically. Large-scale resection of primary cutaneous melanoma is often used to avoid postoperative recurrence. For advanced patients, radiotherapy, targeted therapy and immunotherapy are often needed. Low-temperature plasma has been proved to have significant antitumor effects on a variety of cancer cell lines cultured in vitro. The main limitation of direct low-temperature plasma treatment is that it has weak penetration ability and can only treat superficial lesions. In recent years, research on low-temperature plasma-activated solution has revealed that it also have good antitumor effects and low-temperature plasma penetration depth problems can be solved by local injection. The present study revealed that low-temperature plasma-activated phosphate buffer solution exhibited good antitumor effects and biosafety against melanoma in vitro and in vivo. It demonstrated that low-temperature plasma-activated solution has antitumor effects due to its regulation of intracellular redox, destruction of mitochondrial function and DNA damage. In vivo experiments demonstrated that treatment with low-temperature plasma-activated solution not only exhibited antitumor effects but also caused no significant damage to hematopoietic function or liver and kidney functions in mice. All these results demonstrated that low-temperature plasma-activated solution represent a promising antitumor treatment strategy. [ABSTRACT FROM AUTHOR]

We present a novel plasma system that can generate a plasma‐activated medium by changing the proportion of reactive gases such as oxygen, nitrogen, and hydrogen in the plasma flow. The correlation between the biological activity of plasma‐activated solutions prepared under multiple plasma gas‐flow conditions was evaluated. Mixed nitrogen, in addition to oxygen, in the gas flow is most powerful for producing plasma‐activated Ringer's lactate solution against antitumor effects on ovarian cancer cells as compared with oxygen or nitrogen alone. The antitumor effect of plasma‐activated solutions is controllable by the modification of the proportion of reactive gases (especially nitrogen and oxygen gases) in the plasma flow. These results suggest that the plasma flow conditions may be one of the candidates for the specifications of the plasma‐activated solutions to the therapeutic effect. [ABSTRACT FROM AUTHOR]

The interactions between plasma‐generated excited particles and water play an integral role in sustainable degradation of pharmaceutical compounds, improving aerobic respiration of activated sludge, and efficient removal of microorganisms from water, and are fundamental to the intentional transfer of reactivity from plasmas to biological solutions for such medical applications as cancer treatment and wound healing. The physical and chemical mechanisms that govern this transfer of reactivity are complex, and include concomitant generation and consumption of species in the gas and liquid phases, and at the interface. As such, it is challenging to predict the quantities of biologically‐active radicals and molecules in liquid phase from gas phase measurements alone. Rapid and accurate quantification of reactive species, such as OH radicals and H2O2 molecules within the liquid phase and their link to specific biological effects is therefore critical for medical applications of plasma‐activated solutions. Using a simple, low‐cost method for trapping and stabilization of OH radicals by means of salicylic acid, this work seeks to provide further insights into the physics and chemistry of generation of OH radicals within the liquid phase, and integrate these findings with decontamination outcomes for four commonly used processing gases. [ABSTRACT FROM AUTHOR]

In recent years, plasma-activated solutions (PASs) have made good progress in the disinfection of medical devices, tooth whitening, and fruit preservation. In this study, we investigated the inactivation efficacy of Newcastle disease virus by PASs. Water, 0.9% NaCl, and 0.3% H2O2 were excited by plasma to obtain the corresponding solutions PAS(H2O), PAS(NaCl), and PAS(H2O2). The complete inactivation of virus after PAS treatment for 30 min was confirmed by the embryo lethality assay (ELA) and hemagglutination (HA) test. Scanning electron microscopy (SEM) results showed that the morphology of the viral particle changed under PAS treatments. The total protein concentration of virus decreased as measured by a Bradford protein assay due to PAS treatment. The nucleic acid integrity assay demonstrated that viral RNA degraded into smaller fragments. Moreover, the physicochemical properties of PASs, including the oxidation-reduction potential (ORP), electrical conductivity, and H2O2 concentration, and electron spin resonance spectra analysis indicated that reactive oxygen and nitrogen species play a major role in the virus inactivation. Therefore, the application of PASs, as an environmentally friendly method, would be a promising alternative strategy in poultry industries. [ABSTRACT FROM AUTHOR]

Plasma pharmacy is a subset of the broader field of plasma medicine. Although not strictly defined, the term aqueous plasma pharmacy (APP) is used to refer to the generation and distribution of reactive plasma-generated species in an aqueous solution followed by subsequent administration for therapeutic benefits. APP attempts to harness the therapeutic effects of plasma-generated oxidant species within aqueous solution in various applications, such as disinfectant solutions, cell proliferation related to wound healing, and cancer treatment. The subsequent use of plasma-generated solutions in the APP approach facilitates the delivery of reactive plasma species to internal locations within the body. Although significant efforts in the field of plasma medicine have concentrated on employing direct plasma plume exposure to cells or tissues, here we focus specifically on plasma discharge in aqueous solution to render the solution biologically active for subsequent application. Methods of plasma discharge in solution are reviewed, along with aqueous plasma chemistry and the applications for APP. The future of the field also is discussed regarding necessary research efforts that will enable commercialization for clinical deployment.