Nonthermal Biocompatible Plasma Inactivation of Coronavirus SARS-CoV-2: Prospects for Future Antiviral 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.

Non-thermal plasma disinfecting procedure is harmless to delicate items of everyday use

Non-thermal plasma (NTP) is a well-known decontamination tool applicable for a wide range of microorganisms and viruses. Since the recent COVID-19 pandemic highlighted the need to decontaminate all daily used items, it is highly desirable to address the applicability of NTP, including its possible harmful effects. To the best of our knowledge, a comprehensive characterization of NTP effects on sensitive materials is still lacking. We investigated the potential damage to common materials of daily use inflicted by air atmospheric NTP generated in Plasmatico v1.0. The materials tested were paper, various metals, and passive and active electronic components modelling sensitive parts of commonly used small electronic devices. The NTP-exposed paper remained fully usable with only slight changes in its properties, such as whitening, pH change, and degree of polymerization. NTP caused mild oxidation of copper, tinned copper, brass, and a very mild oxidation of stainless steel. However, these changes do not affect the normal functionality of these materials. No significant changes were observed for passive electronic components; active components displayed a very slight shift of the measured values observed for the humidity sensor. In conclusion, NTP can be considered a gentle tool suitable for decontamination of various sensitive materials.

Persistence of Coronavirus on Surface Materials and Its Control Measures Using Nonthermal Plasma and Other Agents

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has been responsible for the initiation of the global pandemic since 2020. The virus spreads through contaminated air particles, fomite, and surface-contaminated porous (i.e., paper, wood, and masks) and non-porous (i.e., plastic, stainless steel, and glass) materials. The persistence of viruses on materials depends on porosity, adsorption, evaporation, isoelectric point, and environmental conditions, such as temperature, pH, and relative humidity. Disinfection techniques are crucial for preventing viral contamination on animated and inanimate surfaces. Currently, there are few effective methodologies for preventing SARS-CoV-2 and other coronaviruses without any side effects. Before infection can occur, measures must be taken to prevent the persistence of the coronavirus on the surfaces of both porous and non-porous inanimate materials. This review focuses on coronavirus persistence in surface materials (inanimate) and control measures. Viruses are inactivated through chemical and physical methods; the chemical methods particularly include alcohol, chlorine, and peroxide, whereas temperature, pH, humidity, ultraviolet irradiation (UV), gamma radiation, X-rays, ozone, and non-thermal, plasma-generated reactive oxygen and nitrogen species (RONS) are physical methods.

Special Issue "Advances in Antiviral Agents against SARS-CoV-2 and Its Variants"

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with 770 million reported cases and around 7 million deaths, represents the worst pandemic in the last 100 years [...].

Non-Thermal Plasma Application in Medicine-Focus on Reactive Species Involvement

Non-thermal plasma (NTP) application in medicine is a dynamically developing interdisciplinary field. Despite the fact that basics of the plasma phenomenon have been known since the 19th century, growing scientific attention has been paid in recent years to the use of plasma in medicine. Three most important plasma-based effects are pivotal for medical applications: (i) inactivation of a broad spectrum of microorganisms, (ii) stimulation of cell proliferation and angiogenesis with lower plasma treatment intensity, and (iii) inactivation of cells by initialization of cell death with higher plasma intensity. In this review, we explain the underlying chemical processes and reactive species involvement during NTP in human (or animal) tissues, as well as in bacteria inactivation, which leads to sterilization and indirectly supports wound healing. In addition, plasma-mediated modifications of medical surfaces, such as surgical instruments or implants, are described. This review focuses on the existing knowledge on NTP-based in vitro and in vivo studies and highlights potential opportunities for the development of novel therapeutic methods. A full understanding of the NTP mechanisms of action is urgently needed for the further development of modern plasma-based medicine.

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

Optimizing the therapeutic range of nonthermal atmospheric pressure plasma (NTAPP) for biomedical applications is an active research topic. For the first time, we examined the effect of plasma on-times in this study while keeping the duty ratio and treatment time fixed. We have evaluated the electrical, optical, and soft jet properties for two different duty ratios of 10% and 36%, using the plasma on-times of 25, 50, 75, and 100 ms. Furthermore, the influence of plasma on-time on reactive oxygen and nitrogen species (ROS/RNS) levels in plasma treated medium (PTM) was also investigated. Following treatment, the characteristics of (DMEM media) and PTM (pH, EC, and ORP) were also examined. While EC and ORP rose by raising plasma on-time, pH remained unchanged. Finally, the PTM was used to observe the cell viability and ATP levels in U87-MG brain cancer cells. We found it interesting that, by increasing the plasma on-time, the levels of ROS/RNS dramatically increased in PTM and significantly affected the viability and ATP levels of the U87-MG cell line. The results of this study provide a significant indication of advancement by introducing the optimization of plasma on-time to increase the efficacy of the soft plasma jet for biomedical applications.