Effect of Plasma On-Time with a Fixed Duty Ratio on Reactive Species in Plasma-Treated Medium and Its Significance in Biological Applications

Comparative assessment of UV-C radiation and non-thermal plasma for inactivation of foodborne fungal spores suspension in vitro

Fungal contamination poses a persistent challenge to industries, particularly in food, healthcare, and clinical sectors, due to the remarkable resilience of fungi in withstanding conventional control methods. In this context, our research delves into the comparative efficacy of UV radiation and non-thermal plasma (NTP) on key foodborne fungal contaminants - Alternaria alternata, Aspergillus niger, Fusarium culmorum, and Fusarium graminearum. The study examined the impact of varying doses of UV radiation on the asexual spores of all mentioned fungal strains. Simultaneously, the study compared the effects of UV radiation and NTP on the metabolic activity of cells after spore germination and their subsequent germination ability. The results revealed that UV-C radiation (254 nm) did not significantly suppress the metabolic activity of cells after spore germination. In contrast, NTP exhibited almost 100% effectiveness on both selected spores and their subsequent germination, except for A. niger. In the case of A. niger, the effectiveness of UV-C and NTP was nearly comparable, showing only a 35% decrease in metabolic activity after 48 hours of germination, while the other strains (A. alternata, F. culmorum, F. graminearum) exhibited a reduction of more than 95%. SEM images illustrate the morphological changes in structure of all tested spores after both treatments. This study addresses a crucial gap in existing literature, offering insights into the adaptation possibilities of treated cells and emphasizing the importance of considering exposure duration and nutrient conditions (introduction of fresh medium). The results highlighted the promising antimicrobial potential of NTP, especially for filamentous fungi, paving the way for enhanced sanitation processes with diverse applications.

Improvement of transdermal absorption rate by nonthermal biocompatible atmospheric pressure plasma

Nonthermal biocompatible plasma (NBP) is a promising option for improving medication absorption into the human skin. Currently, most plasma devices for cosmetics employ a floating-electrode plasma source for treating the skin. Human skin serves as the ground electrode in the floating-electrode plasma discharge, and discharge occurs between the skin and electrodes of the device. In this in vitro study, we aimed to evaluate the effect of NBP on the skin permeation of niacinamide. We have quantified the transdermal absorption rates of niacinamide in both untreated skin and skin treated with NBP for a duration of 10 s. The absorption of niacinamide for both without and with NBP treatment was observed until 12 h incubation time. Without plasma treatment, the human skin exhibited stable and low transdermal absorption of niacinamide up to 12 h. However, the NBP treatment significantly increased the transdermal absorption of niacinamide from 0.5 h to 6 h and continuously increased skin penetration over a duration of more than 12 h incubation period. The obtained results suggest that NBP-treated human skin showed a 60-fold higher penetration rate than non-treated skin. The increased penetration rate of niacinamide can be mainly attributed to plasmaporation subsequent to NBP treatment. The findings of this study demonstrate that NBP treatment results in remarkable skin permeability, making it a promising candidate for both cosmetic and pharmaceutical delivery applications.

Low-Temperature Plasma Techniques in Biomedical Applications and Therapeutics: An Overview

Plasma, the fourth fundamental state of matter, comprises charged species and electrons, and it is a fascinating medium that is spread over the entire visible universe. In addition to that, plasma can be generated artificially under appropriate laboratory techniques. Artificially generated thermal or hot plasma has applications in heavy and electronic industries; however, the non-thermal (cold atmospheric or low temperature) plasma finds its applications mainly in biomedicals and therapeutics. One of the important characteristics of LTP is that the constituent particles in the plasma stream can often maintain an overall temperature of nearly room temperature, even though the thermal parameters of the free electrons go up to 1 to 10 keV. The presence of reactive chemical species at ambient temperature and atmospheric pressure makes LTP a bio-tolerant tool in biomedical applications with many advantages over conventional techniques. This review presents some of the important biomedical applications of cold-atmospheric plasma (CAP) or low-temperature plasma (LTP) in modern medicine, showcasing its effect in antimicrobial therapy, cancer treatment, drug/gene delivery, tissue engineering, implant modifications, interaction with biomolecules, etc., and overviews some present challenges in the field of plasma medicine.

Effect of Plasma-Treated Water with Magnesium and Zinc on Growth of Chinese Cabbage

Nonthermal biocompatible plasma (NBP) is an emerging technology in the field of agriculture to boost plant growth. Plasma is a source of various gaseous reactive oxygen and nitrogen species (RONS) and has a promising role in agricultural applications, as the long-lived RONS (H₂O₂, NO₂^-, NO₃^-) in liquid activate signaling molecules in plant metabolism. Plasma-treated water (PTW) has an acidic pH of around 3 to 4, which may be detrimental to pH-sensitive plants. Innovative techniques for producing PTW with a pH value of 6 to 7 under neutral circumstances are desperately required to broaden the application range of NBP in agriculture. Furthermore, Pak Choi (Brassica campestris L.) is a Brassicaceae family green vegetable that has yet to be investigated for its response to NBP. In this work, we proposed an alternate method for neutralizing the pH of PTW by immersing metal ions (Mg²⁺ and Zn²⁺) in the PTW and observing its effect on Pak Choi. After synthesizing PTW with MECDBD, we analyzed germination rate and growth parameters, then seedlings for 42 days to show physiological, biochemical, and molecular levels. The germination rate was observed to be higher with PTW and more efficient when metal ions were present. Seedling length and germination rates were dramatically boosted when compared to DI water irrigation. Because of the increased chlorophyll and protein content, the plants responded to the availability of nitrogen by generating highly green leaves. Furthermore, we observed that PTW increases the expression of NR genes and GLR1 genes, which are further increased when metals are submerged in the PTW. Furthermore, PTW and PTW with metals reduced ABI5 and CHO1 which is associated with a growth inhibitor. According to this study, nonthermal plasma might be utilized to significantly improve seed germination and seedlings' development.