Skin renewal activity of non-thermal plasma through the activation of β-catenin in keratinocytes

Inhibition of glutamine metabolism increases sensitivity to plasma-activated medium-induced cytotoxicity

Non-thermal atmospheric pressure plasma (NTP), an ionized gas containing electrons, ions, radicals, and photons, has various biological effects, including wound healing and anticancer effects. Plasma-activated medium (PAM), which is prepared by irradiating medium with NTP, preferentially kills cancer cells. Large amounts of reactive oxygen species (ROS) and reactive nitrogen species (RNS) included in PAM are closely related to its anticancer effects. The precise mechanism of PAM-induced cytotoxicity is not fully understood; however, PAM exposure has been reported to reduce cellular energy metabolism. Glutamine (Gln) is an important amino acid as an energy source in cancer cells. Gln is converted to glutamate by glutaminase (GLS), and is utilized to synthesize ATP and glutathione (GSH). Expression levels of GLS have been shown to be higher in certain types of cancers. In this study, we examined the effects of GLS inhibition on PAM cytotoxicity using breast cancer MDA-MB-231 cells. Pretreatment with BPTES, a glutaminase 1 (GLS1) inhibitor, dose-dependently enhanced PAM-induced cell death. PAM-induced ROS production and γ-H2AX formation, a DNA damage marker, were increased in cells pretreated with BPTES compared with PAM alone. BPTES pretreatment enhanced a PAM-induced decrease in intracellular GSH, indicating the possibility that BPTES reduces the antioxidant capacity of MDA-MB-231 cells. In addition, BPTES pretreatment enhanced PAM-induced loss of the mitochondrial membrane potential and reduction of ATP production. Moreover, GLS1 knockdown promoted PAM-induced cell death. Taken together, the combination of GLS1 inhibitors such as BPTES is considered to be useful for enhancing the cytotoxic effects of PAM against cancer cells.

No-ozone cold plasma induces apoptosis in human neuroblastoma cell line via increased intracellular reactive oxygen species (ROS)

BACKGROUND

This study aimed to evaluate the effect of argon-based No-ozone Cold Plasma (NCP) on neuroblastoma cancer cell apoptosis.

METHODS

Experiments were performed with SK-N-SH and HS 68. Cell cultures were treated with NCP for 1, 3, and 5 min. NCP was applied using three different strategies: direct NCP application to cell cultures, to only media, and to only cells. Evaluation of cell viability and the level of the reactive oxygen species (ROS) was performed. N-acetyl-L-cysteine (NAC) was also used to antagonize intracellular ROS. Cleaved caspase 3, PARP, aquaporin (AQP) 3 and 8 were detected.

RESULTS

NCP induced a gradual decrease in the SK-N-SH cell viability. In contrast, the viability of HS 68 cells did not change. SK-N-SH cells viability was reduced the most when the only media-NCP application strategy was employed. Intracellular ROS levels were significantly increased with time. Cleaved caspase 3 and PARP were increased at 6 h after NCP application. SK-N-SH cells remained viable with NAC after NCP application. AQP 3 and 8 were over-expressed in SK-N-SH cells.

CONCLUSION

These findings demonstrate the anti-cancer effect of NCP on neuroblastoma cells. NCP enhanced the selective apoptosis of neuroblastoma cells due to the increased intracellular ROS.

High-frequency plasma spark discharge assessment in pulse-scanning digital holographic interferometry

In this paper, we consider the method for observing and detecting of high-frequency pulsed plasma spark discharge by means of stroboscopic digital holographic interferometry to demonstrate the feasibility of the electron concentration assessment in nonthermal plasma. A spark discharge with a 5 kHz frequency and 1250 ns duration has been exited between two electrodes in atmospheric pressure. The sequence of holograms acquired due to the proper synchronization between plasma pulses, laser radiation, and the camera's frame grabbing that ensure the recording of the plasma pulses at different moments of time, and the temporal optical scanning of plasma pulse were realized. We also show that the phase difference contrast variation corresponds to the plasma's instant and indicates a change in the electron concentration in the discharge. The concentration of electrons at different moments of plasma existence has been estimated. The limitations of the proposed method are considered, and its applicability for the study of low-temperature pulsed plasma are discussed.

Topical Application of No-Ozone Cold Plasma in Combination with Vitamin C Reduced Skin Redness and Pigmentation of UV-Irradiated Mice

Ultraviolet (UV) is the main cause of sunburn on the skin as it induces erythema and accelerates pigmentation. Vitamin C is one of the most frequently used compounds to reduce UV-induced skin pigmentation, but it has limitations in absorption through the skin. In this study, we tested whether a no-ozone cold plasma (NCP) treatment can improve UV-irradiated skin by helping the action of Vitamin C. For this, among five groups of HRM-2 hairless mice, four groups of mice were subjected to UVB irradiation, and three groups of UVB-treated mice were treated with NCP, Vitamin C, and NCP + Vitamin C, respectively. For evaluating the effect of each treatment, the melanin and erythema index was measured during animal experiments. Histological changes were monitored by performing H&E and MTS and IHC against tyrosinase and melanin. As a result, the naturally recovered mice showed a 28-point decrease in the melanin index, whereas a decrease of around 88, 74.3, and 106 points was detected in NCP-, Vitamin C-, and NCP + vitamin C-treated mice, respectively. Likewise, only a 39-point reduction in the erythema index was monitored in naturally recovered mice, but the NCP-, vitamin C-, and NCP + vitamin C-treated mice showed a 87.3-, 77-, and 111-point reduction, respectively. Interestingly, the skin tissues of the mice treated with NCP in combination with Vitamin C mostly recovered from UVB-induced damage. Altogether, this study elucidated the beneficial effect of the treatment of NCP in combination with Vitamin C on the UVB-irradiated skin, which might be helpful for treating sunburn on the skin.

Non-thermal plasma directly accelerates neuronal proliferation by stimulating axon formation

Among the various methods, Non Thermal Plasma (NTP) has been recently introduced and is being studied to recover the damaged nerve. In the recent years, several studies have suggested that NTP accelerates nerve cell regeneration, but the mechanism remains unknown. This study evaluated the effect of NTP on neuronal proliferation in SH-SY5Y (Human neuroblastoma cells) cells differentiated by retinoic acid (RA) and investigated the mechanism by which NTP promotes cell proliferation. We analyzed the morphology of differentiated SH-SY5Y cells, and performed western blot analysis and reverse transcription polymerase chain reaction (RT-PCR). Immunofluorescence analysis was performed in an in vivo study by categorizing Wistar A rats into three groups: non-nerve damage (Non-ND), nerve damage (ND), and nerve damage + NTP treatment (ND + NTP). The cell morphology analysis revealed that the number of cells increased and axonal elongation progressed after NTP treatment. In addition, western blots indicated that tau expression increased significantly after NTP treatment. The RT-PCR results revealed that the expression of tau, wnt3a, and β-catenin increased after NTP treatment. The in vivo immunofluorescence assay showed that NTP increased the markers for tau and S100B while regulating the over-expression of MAP2 and GAP43. NTP treatment accelerated cell proliferation and regeneration of damaged neurons in differentiated SH-SY5Y cells. These results establish the fact of NTP as a noninvasive and effective treatment for nerve injury.

Anti-Cancer Activity of the Combinational Treatment of Noozone Cold Plasma with p-FAK Antibody-Conjugated Gold Nanoparticles in OSCC Xenograft Mice

Oral squamous cell cancer (OSCC) is the most common type of oral cancer (about 80–90% of cases) and various research is being done to cure the disease. This paper aims to verify whether treatment with no-ozone cold plasma (NCP), which is designed for safe usage of the plasma on oral cavities, in combination with gold nanoparticles conjugated with p-FAK antibody (p-FAK/GNP) can trigger the selective and instant killing of SCC-25 cells both in vitro and in vivo. When SCC25 and HaCaT cells are exposed to p-FAK/GNP+NCP, the instant cell death was observed only in SCC25 cells. Such p-FAK/GNP+NCP-mediated cell death was observed only when NCP was directly treated on SCC25 harboring p-FAK/GNP. During NCP treatment, the removal of charged particles from NCP using grounded electric mesh radically decreased the p-FAK/GNP+NCP-mediated cell death. This p-FAK/GNP+NCP-mediated selective cell death of OSCC was also observed in mice xenograft models using SCC25 cells. The mere treatment of p-FAK/GNP and NCP on the xenograft tumor slowly decreased the size of the tumor, and only about 50% of the tumor remained at the end of the experiment. On the other hand, 1 week of p-FAK/GNP+NCP treatment was enough to reduce half of the tumor size, and most of tumor tissue had vanished at the end. An analysis of isolated tissues showed that in the case of individual treatment with p-FAK/GNP or NCP, the cancer cell population was reduced due to apoptotic cell death. However, in the case of p-FAK/GNP+NCP, apoptotic cell death was unobserved, and most tissues were composed of collagen. Thus, this paper suggests the possibility of p-FAK/GNP+NCP as a new method for treating OSCC.

Biological Risk Assessment of Three Dental Composite Materials following Gas Plasma Exposure

Gas plasma is an approved technology that generates a plethora of reactive oxygen species, which are actively applied for chronic wound healing. Its particular antimicrobial action has spurred interest in other medical fields, such as periodontitis in dentistry. Recent work has indicated the possibility of performing gas plasma-mediated biofilm removal on teeth. Teeth frequently contain restoration materials for filling cavities, e.g., resin-based composites. However, it is unknown if such materials are altered upon gas plasma exposure. To this end, we generated a new in-house workflow for three commonly used resin-based composites following gas plasma treatment and incubated the material with human HaCaT keratinocytes in vitro. Cytotoxicity was investigated by metabolic activity analysis, flow cytometry, and quantitative high-content fluorescence imaging. The inflammatory consequences were assessed using quantitative analysis of 13 different chemokines and cytokines in the culture supernatants. Hydrogen peroxide served as the control condition. A modest but significant cytotoxic effect was observed in the metabolic activity and viability after plasma treatment for all three composites. This was only partially treatment time-dependent and the composites alone affected the cells to some extent, as evident by differential secretion profiles of VEGF, for example. Gas plasma composite modification markedly elevated the secretion of IL6, IL8, IL18, and CCL2, with the latter showing the highest correlation with treatment time (Pearson’s r > 0.95). Cell culture media incubated with gas plasma-treated composite chips and added to cells thereafter could not replicate the effects, pointing to the potential that surface modifications elicited the findings. In conclusion, our data suggest that gas plasma treatment modifies composite material surfaces to a certain extent, leading to measurable but overall modest biological effects.

Plasma Dermatology: Skin Therapy Using Cold Atmospheric Plasma

Cold atmospheric plasma-based plasma medicine has been expanding the diversity of its specialties. As an emerging branch, plasma dermatology takes advantage of the beneficial complexity of plasma constituents (e.g., reactive oxygen and nitrogen species, UV photons, and electromagnetic emission), technical versatility (e.g., direct irradiation and indirect aqueous treatment), and practical feasibility (e.g., hand-held compact device and clinician-friendly operation). The objective of this comprehensive review is to summarize recent advances in the CAP-dominated skin therapy by broadly covering three aspects. We start with plasma optimisation of intact skin, detailing the effect of CAP on skin lipids, cells, histology, and blood circulation. We then conduct a clinically oriented and thorough dissection of CAP treatment of various skin diseases, focusing on the wound healing, inflammatory disorders, infectious conditions, parasitic infestations, cutaneous malignancies, and alopecia. Finally, we conclude with a brief analysis on the safety aspect of CAP treatment and a proposal on how to mitigate the potential risks. This comprehensive review endeavors to serve as a mini textbook for clinical dermatologists and a practical manual for plasma biotechnologists. Our collective goal is to consolidate plasma dermatology’s lead in modern personalized medicine.

No-ozone cold plasma can kill oral pathogenic microbes in H2O2-dependent and independent manner

To apply the sterilisation effect of low-temperature plasma to the oral cavity, the issue of ozone from plasma must be addressed. In this study, a new technology for generating cold plasma with almost no ozone is developed and is named Nozone (no-ozone) Cold Plasma (NCP) technology. The antimicrobial efficacy of the NCP against four oral pathogens is tested, and its specific mechanism is elucidated. The treatment of NCP on oral pathogenic microbes on a solid medium generated a growth inhibition zone. When NCP is applied to oral pathogens in a liquid medium, the growth of microbes decreased by more than 10⁵ colony forming units, and the bactericidal effect of NCP remained after the installation of dental tips. The bactericidal effect of NCP in the liquid medium is due to the increase in hydrogen peroxide levels in the medium. However, the bactericidal effect of NCP in the solid medium depends on the charged elements of the NCP. Furthermore, the surface bactericidal efficiency of the dental-tip-installed NCP is proportional to the pore size of the tips and inversely proportional to the length of the tips. Overall, we expect this NCP device to be widely used in dentistry in the near future.

Analysis of fibroblast pen usage amongst TikTok social media users

Social media networks serve as convenient platforms for the dissemination of information, including that which pertains to healthcare. However, social media networks may also disseminate incorrect information, and may even propagate potentially harmful skincare trends. Since its inception in 2016, TikTok, a social media platform wherein users can create and share videos, has served as a tool for the propagation of multiple, potentially dangerous cosmetic trends, most recently the usage of fibroblast pens.^1,2 Fibroblast pens, also known as plasma pens, are toted to produce a variety of skincare benefits. However, many of the pens being sold commercially, and subsequently used on TikTok, are not FDA-regulated. Potential adverse effects include the development of dyspigmentation, scarring, and mechanical burns of the skin.³ This study assessed social media content to improve our understanding of fibroblast pen usage amongst TikTok creators. An initial search of public TikTok posts tagged with "#PlasmaPen," "#PlasmaPenTreatment," "#FibroblastPlasma," or "#FibroblastPlasmaPen" identified 200 posts, of which 78 were eliminated after accounting for overlapping posts between hashtags, posts that were later deleted by the user, and those in languages other than English. We analyzed posts according to creator type and classified them into four main themes. The 78 videos were later re-viewed to provide more detailed subdivisions within the four main themes. Analysis showed that 36% of the posts were created by lay-person TikTok users, followed by 25% of posts being created by self-proclaimed fibroblast skin tightening specialists. Major themes include advertisement of the fibroblast pen (61%), experience with the fibroblast pen (26%), education on the fibroblast pen's uses and benefits (6.5%), and warnings related to usage of the pen (6.5%). TikTok users are more likely to encounter a post regarding fibroblast pen usage from uncredentialled, non-medical professional accounts. Only 6.5% of posts were created with the intention of serving as a warning to users, with most of these posts being created by medical doctors. Dermatologists should be aware of the misinformation regarding fibroblast pens and consider posting on social media to raise awareness about this potentially dangerous skincare trend.

Experimental Study of a Nonthermal DBD-Driven Plasma Jet System Using Different Supply Methods

This article presents an experimental study of a DBD-driven plasma jet system. The aim of the study is to design a whole system (the jet reactor, its electrical power supply, and a gas-feeding apparatus) suitable for biomedical applications. The article describes the test bench developed for this purpose and discusses the parameters it controls. The measurements show that the studied solutions can be used to control critical parameters such as the jet temperature and dimensions. The best results were obtained for a bipolar short-pulse voltage power supply in the 10–20 kHz frequency range and for a series resonant inverter current power supply operated in “burst mode”, allowing low-frequency modulation.

Enhancement of Osteoblast Differentiation Using No-Ozone Cold Plasma on Human Periodontal Ligament Cells

Periodontitis is an inflammatory disease that leads to periodontal tissue destruction and bone resorption. Proliferation and differentiation of cells capable of differentiating into osteoblasts is important for reconstructing periodontal tissues destroyed by periodontitis. In this study, the effects of the nozone (no-ozone) cold plasma (NCP) treatment on osteoblastic differentiation in periodontal ligament (PDL) cells were investigated. To test the toxicity of NCP on PDL cells, various NCP treatment methods and durations were tested, and time-dependent cell proliferation was analyzed using a water-soluble tetrazolium salts-1 assay. To determine the effect of NCP on PDL cell differentiation, the cells were provided with osteogenic media immediately after an NCP treatment to induce differentiation; the cells were then analyzed using alkaline phosphatase (ALP) staining, an ALP activity assay, real time PCR, and Alizarin Red S staining. The NCP treatment without toxicity on PDL cells was the condition of 1-min NCP treatment immediately followed by the replacement with fresh media. NCP increased ALP, osteocalcin, osteonectin, and osteopontin expression, as well as mineralization nodule formation. NCP treatment promotes osteoblastic differentiation of PDL cells; therefore, it may be beneficial for treating periodontitis.

Investigation of Nonthermal Plasma Jet Excitation Mode and Optical Assessment of Its Electron Concentration

The results of a study of a plasma jet of atmospheric-pressure helium driven by a capacitive discharge using sine and pulsed modes of excitation are presented. The homogeneous discharge of a multi-channel plasma jet at gas temperature of 34 °C and helium flow rate of 0.5 L/min was achieved with short pulse excitation. A digital holography method is proposed to estimate a basic plasma parameter, i.e., its electron concentration. An automated digital holographic interferometry set-up for the observation and study of a nonthermal plasma jet in a pulse mode is developed and described. The synchronization features of recording devices with the generation of plasma pulses are considered. The electron concentration of the plasma jet is also estimated. The disadvantages of the proposed technique and its further application are discussed.

Non-thermal atmospheric pressure plasma activates Wnt/β-catenin signaling in dermal papilla cells

There is an unmet need for novel, non-pharmacological therapeutics to treat alopecia. Recent studies have shown the potential biological benefits of non-thermal atmospheric pressure plasma (NTAPP), including wound healing, angiogenesis, and the proliferation of stem cells. We hypothesized that NTAPP might have a stimulatory effect on hair growth or regeneration. We designed an NTAPP-generating apparatus which is applicable to in vitro and in vivo experiments. The human dermal papilla (DP) cells, isolated fresh hair follicles, and mouse back skin were exposed with the NTAPP. Biological outcomes were measured using RNA-sequencing, RT-PCR, Western blots, and immunostaining. The NTAPP treatment increased the expression levels of Wnt/β-catenin pathway-related genes (AMER3, CCND1, LEF1, and LRG1) and proteins (β-catenin, p-GSK3β, and cyclin D1) in human DP cells. In contrast, inhibitors of Wnt/β-catenin signaling, endo-IWR1 and IWP2, attenuated the levels of cyclin D1, p-GSK3β, and β-catenin proteins induced by NTAPP. Furthermore, we observed that NTAPP induced the activation of β-catenin in DP cells of hair follicles and the mRNA levels of target genes of the β-catenin signaling pathway (CCND1, LEF1, and TCF4). NTAPP-treated mice exhibited markedly increased anagen induction, hair growth, and the protein levels of β-catenin, p-GSK3β, p-AKT, and cyclin D1. NTAPP stimulates hair growth via activation of the Wnt/β-catenin signaling pathway in DP cells. These findings collectively suggest that NTAPP may be a potentially safe and non-pharmacological therapeutic intervention for alopecia.

Protective effects of non-thermal plasma on triethylene glycol dimethacrylate-induced damage in odontoblast-like MDPC-23 cells

AIM

To evaluate whether the use of non-thermal plasma (NTP) could reduce triethylene glycol dimethacrylate (TEGDMA)-mediated damage in MDPC-23 cells.

METHODOLOGY

The effects of NTP and TEGDMA on MDPC-23 cell proliferation were tested using WST-1 assays after pretreatment with NTP for 1 min and exposure to TEGDMA. Live/Dead assays were used to visualize cell death. To monitor the effects of NTP and TEGDMA on the cell cycle and apoptotic cell death, flow cytometry was performed. Western blotting was used to assess changes in protein levels mediated by NTP and TEGDMA treatment, and enzyme-linked immunosorbent assays were performed to evaluate the effects of NTP and TEGDMA on prostaglandin E₂ (PGE₂ ) expression. One-way analysis of variance and Duncan's post hoc tests were used for statistical analysis.

RESULTS

NTP treatment effectively protected cells from TEGDMA-mediated cell damage and blocked TEGDMA-mediated cell growth inhibition (p < .05). NTP appeared to protect cells from death (p < .05) and blocked TEGDMA-mediated apoptotic cell death. Additionally, NTP reduced TEGDMA-mediated apoptotic activation of poly (ADP) ribose polymerase-1 and caspase-3 (p < .05). Furthermore, NTP effectively reduced TEGDMA-mediated expression of cyclooxygenase-2 and PGE₂ proteins by inhibiting nuclear factor-κB protein expression (p < .05).

CONCLUSIONS

NTP alleviated TEGDMA-mediated adverse effects by reducing cytotoxicity and inflammatory reactions in cells exposed to TEGDMA.

A proline derivative-enriched methanol fraction from Sideroxylon obtusifolium leaves (MFSOL) stimulates human keratinocyte cells and exerts a healing effect in a burn wound model

It was previously demonstrated that the methanol fraction of Sideroxylon obtusifolium (MFSOL) promoted anti-inflammatory and healing activity in excisional wounds. Thus, the present work investigated the healing effects of MFSOL on human keratinocyte cells (HaCaT) and experimental burn model injuries. HaCaT cells were used to study MFSOL's effect on cell migration and proliferation rates. Female Swiss mice were subjected to a second-degree superficial burn protocol and divided into four treatment groups: Vehicle, 1.0% silver sulfadiazine, and 0.5 or 1.0% MFSOL Cream (CrMFSOL). Samples were collected to quantify the inflammatory mediators, and histological analyses were performed after 3, 7, and 14 days. The results showed that MFSOL (50 μg/mL) stimulated HaCaT cells by increasing proliferation and migration rates. Moreover, 0.5% CrMFSOL attenuated myeloperoxidase (MPO) activity and also stimulated the release of interleukin (IL)-1β and IL-10 after 3 days of treatment. CrMFSOL (0.5%) also enhanced wound contraction, promoted improvement of tissue remodeling, and increased collagen production after 7 days and VEGF release after 14 days. Therefore, MFSOL stimulated human keratinocyte (HaCaT) cells and improved wound healing via modulation of inflammatory mediators of burn injuries.

Plasma-mediated enhancement of enzyme secretion in Aspergillus oryzae

Technical bottlenecks in protein production and secretion often limit the efficient and robust industrial use of microbial enzymes. The potential of non-thermal atmospheric pressure plasma to overcome these technical barriers was examined. Spores of the fermenting fungus Aspergillus oryzae (A. oryzae) were submerged in potato dextrose broth (PDB) (5 × 106 per ml) and treated with micro dielectric barrier discharge plasma at an input voltage of 1.2 kV and current of 50 to 63 mA using nitrogen as the feed gas. The specific activity of α-amylase in the broth was increased by 7.4 to 9.3% after 24 and 48 h of plasma treatment. Long-lived species, such as NO2 - and NO3 - , generated in PDB after plasma treatment may have contributed to the elevated secretion of α-amylase. Observations after 24 h of plasma treatment also included increased accumulation of vesicles at the hyphal tip, hyphal membrane depolarization and higher intracellular Ca2+ levels. These results suggest that long-lived nitrogen species generated in PDB after plasma treatment can enhance the secretion of α-amylase from fungal hyphae by depolarizing the cell membrane and activating Ca2+ influx into hyphal cells, eventually leading to the accumulation of secretory vesicles near the hyphal tips.

The emerging potential of cold atmospheric plasma in skin biology

The maintenance of skin integrity is crucial to ensure the physiological barrier against exogenous compounds, microorganisms and dehydration but also to fulfill social and aesthetic purposes. Besides the development of new actives intended to enter a formulation, innovative technologies based on physical principles have been proposed in the last years. Among them, Cold Atmospheric Plasma (CAP) technology, which already showed interesting results in dermatology, is currently being studied for its potential in skin treatments and cares. CAP bio-medical studies gather several different expertise ranging from physics to biology through chemistry and biochemistry, making this topic hard to pin. In this review we provide a broad survey of the interactions between CAP and skin. In the first section, we tried to give some fundamentals on skin structure and physiology, related to its essential functions, together with the main bases on cold plasma and its physicochemical properties. In the following parts we dissected and analyzed each CAP parameter to highlight the already known and the possible effects they can play on skin. This overview aims to get an idea of the potential of cold atmospheric plasma technology in skin biology for the future developments of dermo-cosmetic treatments, for example in aging prevention.

Potential effect of non-thermal plasma for the inhibition of scar formation: a preliminary report

Non-thermal plasma (NTP) is a promising biomedical tool for application to wound healing. However, there is limited scientific evidence that confirms its efficacy to inhibit scar formation. This study aims to investigate the role of non-thermal plasma in scar formation. Two full-thickness dorsal cutaneous wounds of rats were treated with either a non-thermal helium plasma jet or helium. It was determined that the non-thermal plasma jet accelerated the wound healing process from 5 days after surgery (day 5: 41.27% ± 2.351 vs 54.7% ± 5.314, p < 0.05; day 7: 56.05% ± 1.881 vs 75.28% ± 3.914, p < 0.01; day 14: 89.85% ± 2.991 vs 98.07% ± 0.839, p < 0.05). The width of the scars for the NTP group was narrower than those of control group (4.607 ± 0.416 mm vs 3.260 ± 0.333 mm, p < 0.05). In addition, a lower level of TGF-β1, p-Smad2 and p-Smad3 were detected in the NTP treated wounds (p < 0.05, p < 0.01 and p < 0.01). As expected, α-SMA was also significantly decreased in the NTP treatment group (p < 0.01). Moreover, the expression of type I collagen and the proportion of type I to III collagen were lower in the NTP group (p < 0.05). The results of the study suggest that NTP may play a potential role in scar formation by inhibiting the TGF β1 signal pathway and reducing the levels of α-SMA and type I collagen, and may have clinical utility in the future.

Plasma Permeabilization of Human Excised Full-Thickness Skin by µs- and ns-pulsed DBD

INTRODUCTION

Cold atmospheric plasma (CAP) is gaining increasing importance as a medical or cosmetic treatment for various indications. The technology is best suited to the treatment of surfaces such as the skin and is already used in wound care and, in exemplary case studies, the reduction of superficial tumors. Several plasma sources have been reported to affect the skin barrier function and potentially enable drug delivery across or into plasma-treated skin.

OBJECTIVE

In this study, this effect was quantified for different plasma sources in order to elucidate the influence of voltage rise time, pulse duration, and power density in treatments of full-thickness skin.

METHODS

We compared three different dielectric barrier discharges (DBDs) as to their permeabilization efficiency using Franz diffusion cell permeation experiments and measurements of the transepithelial electrical resistance (TEER) with full-thickness human excised skin.

RESULTS

We found a significant reduction of the TEER for all three plasma sources. Permeation of the hydrophilic sodium fluorescein molecule was enhanced by a factor of 11.7 (low power) to 41.6 (high power) through µs-pulsed DBD-treated skin. A smaller effect was observed after treatment with the ns-pulsed DBD.

CONCLUSIONS

The direct treatment of excised human full-thickness skin with CAP, specifically a DBD, can lead to pore formation and enhances transdermal transport of sodium fluorescein.

Non-thermal plasma accelerates the healing process of peripheral nerve crush injury in rats

The objective of this study was to evaluate the effect of non-thermal plasma (NTP) on the healing process of peripheral nerve crush injuries, which can occur during dental implant procedures. For this, a rat model of sciatic nerve crush injury (SNCI) was adopted. The rats were divided into three groups: non-nerve damage (non-ND), nerve damage (ND), and ND+NTP group. To evaluate the sciatic nerve (SN) function, the static sciatic index was calculated, and the muscle and SN tissues were subjected to a histologic analysis. The results showed that NTP effectively accelerated the healing process of SNCI in rats. In contrast to the ND group, which showed approximately 60% recovery in the SN function, the NTP-treated rats showed complete recovery. Histologically, the NTP treatments not only accelerated the muscle healing, but also reduced the edema-like phenotype of the damaged SN tissues. In the ND group, the SN tissues had an accumulation of CD68-positive macrophages, partially destroyed axonal fibers and myelinated Schwann cells. Conversely, in the ND+NTP group, the macrophage accumulation was reduced and an overall regeneration of the damaged axon fibers and the myelin sheath was accomplished. The results of this study indicate that NTP can be used for healing of injured peripheral nerves.

Plasma Medicine: A Field of Applied Redox Biology

Plasma medicine comprises the application of physical plasma directly on or in the human body for therapeutic purposes. Three most important basic plasma effects are relevant for medical applications: i) inactivation of a broad spectrum of microorganisms, including multidrug-resistant pathogens, 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 treatment intensity, above all in cancer cells. Based on own published results as well as on monitoring of relevant literature the aim of this topical review is to summarize the state of the art in plasma medicine and connect it to redox biology. One of the most important results of basic research in plasma medicine is the insight that biological plasma effects are mainly mediated via reactive oxygen and nitrogen species influencing cellular redox-regulated processes. Plasma medicine can be considered a field of applied redox biology.

ROS from Physical Plasmas: Redox Chemistry for Biomedical Therapy

Physical plasmas generate unique mixes of reactive oxygen and nitrogen species (RONS or ROS). Only a bit more than a decade ago, these plasmas, operating at body temperature, started to be considered for medical therapy with considerably little mechanistic redox chemistry or biomedical research existing on that topic at that time. Today, a vast body of evidence is available on physical plasma-derived ROS, from their spatiotemporal resolution in the plasma gas phase to sophisticated chemical and biochemical analysis of these species once dissolved in liquids. Data from in silico analysis dissected potential reaction pathways of plasma-derived reactive species with biological membranes, and in vitro and in vivo experiments in cell and animal disease models identified molecular mechanisms and potential therapeutic benefits of physical plasmas. In 2013, the first medical plasma systems entered the European market as class IIa devices and have proven to be a valuable resource in dermatology, especially for supporting the healing of chronic wounds. The first results in cancer patients treated with plasma are promising, too. Due to the many potentials of this blooming new field ahead, there is a need to highlight the main concepts distilled from plasma research in chemistry and biology that serve as a mechanistic link between plasma physics (how and which plasma-derived ROS are produced) and therapy (what is the medical benefit). This inevitably puts cellular membranes in focus, as these are the natural interphase between ROS produced by plasmas and translation of their chemical reactivity into distinct biological responses.

Non-thermal plasma inhibits mast cell activation and ameliorates allergic skin inflammatory diseases in NC/Nga mice

Non-thermal plasma (NTP) has many functional activities such as, sterilization, wound healing and anti-cancer activity. Despite of its wide spread biomedical application, the effect of NTP on immune cells and allergic response has not been well studied. In this study, we determined whether NTP suppresses mast cell activation, which is important for allergic response, and ameliorates an atopic dermatitis (AD)-like skin inflammatory disease in mice. Exposure to NTP-treated medium during mast cell activation inhibited the expression and production of IL-6, TNF-α and suppressed NF-κB activation. We also investigated whether NTP treatment ameliorates house dust mite (HDM)-induced AD-like skin inflammation in mice. NTP treatment inhibited increases in epidermal thickness and recruitment of mast cells and eosinophils, which are important cell types in AD pathogenesis. In addition, Th2 cell differentiation was induced by application of HDM and the differentiation was also inhibited in the draining lymph node of NTP-treated mice. Finally, the expression of AD-related cytokines and chemokines was also decreased in NTP-treated mice. Taken together, these results suggest that NTP might be useful in the treatment of allergic skin diseases, such as AD.

Ethanol extract of asiasari radix preferentially induces apoptosis in G361 human melanoma cells by differential regulation of p53

Background

In Korea and China, asiasari radix (AR) is widely used as a traditional anti-inflammatory and analgesic agent. After its skin-regenerating and hair loss-preventing activities were identified, several types of AR extracts were used for aesthetic purposes. Nevertheless, the effect of ARE on various types of skin cancers was not fully studied yet.

Methods

In this study, we tested the effect of an ethanolic AR extract (ARE) on G361 human melanoma and HaCaT human keratinocyte cell lines. After ARE exposure, cell growth and the expression patterns of proteins and genes were monitored.

Results

The ARE-mediated cell growth inhibition was greater in G361 cells than in HaCaT cells due to differences in its cell growth regulation effects. Interestingly, ARE treatment induced caspase-3-mediated apoptosis in G361 cells, but not in HaCaT cells. Furthermore, ARE reduced the expression of p53 and p21 proteins in G361 cells, whereas it induced their expression in HaCaT cells. ARE induced cell death in G361 cells through the reactive oxygen species (ROS)-dependent regulation of p53 and p21 in G361 cells. Microarray analysis showed that ARE regulates Mouse double minute 2 homolog (MDM2) and CASP8 and FADD-like apoptosis regulator (CFLAR) gene expression in G361 and HaCaT cells differently.

Conclusion

The treatment of ARE preferentially induces apoptosis in melanoma cells by the ROS-dependent differential regulation of p53 level. Therefore, ARE can be used as a new medicinal option for melanoma.

Cold atmospheric plasma is a viable solution for treating orthopedic infection: a review

Bacterial infection and antibiotic resistance are major threats to human health and very few solutions are available to combat this eventuality. A growing number of studies indicate that cold (non-thermal) plasma treatment can be used to prevent or eliminate infection from bacteria, bacterial biofilms, fungi and viruses. Mechanistically, a cold plasma discharge is composed of high-energy electrons that generate short-lived reactive oxygen and nitrogen species which further react to form more stable compounds (NO2, H2O2, NH2Cl and others) depending on the gas mixture and plasma parameters. Cold plasma devices are being developed for medical applications including infection, cancer, plastic surgery applications and more. Thus, in this review we explore the potential utility of cold plasma as a non-antibiotic approach for treating post-surgical orthopedic infections.

Physical plasma and leukocytes - immune or reactive?

Leukocytes are professionals in recognizing and removing pathogenic or unwanted material. They are present in virtually all tissues, and highly motile to enter or leave specific sites throughout the body. Less than a decade ago, physical plasmas entered the field of medicine to deliver their delicate mix of reactive species and other physical agents for mainly dermatological or oncological therapy. Plasma treatment thus affects leukocytes via direct or indirect means: immune cells are either present in tissues during treatment, or infiltrate or exfiltrate plasma-treated areas. The immune system is crucial for human health and resolution of many types of diseases. It is therefore vital to study the response of leukocytes after plasma treatment in vitro and in vivo. This review gathers together the major themes in the plasma treatment of innate and adaptive immune cells, and puts these into the context of wound healing and oncology, the two major topics in plasma medicine.

Potential Applications of Non-thermal Plasma in Animal Husbandry to Improve Infrastructure

Infrastructure in animal husbandry refers to fundamental facilities and services necessary for better living conditions of animals and its economy to function through better productivity. Mainly, infrastructure can be divided into two categories: hard infrastructure and soft infrastructure. Physical infrastructure, such as buildings, roads, and water supplying systems, belongs to hard infrastructure. Soft infrastructure includes services which are required to maintain economic, health, cultural and social standards of animal husbandry. Therefore, the proper management of infrastructure in animal husbandry is necessary for animal welfare and its economy. Among various technologies to improve the quality of infrastructure, non-thermal plasma (NTP) technology is an effectively applicable technology in different stages of animal husbandry. NTP is mainly helpful in maintaining better health conditions of animals in several ways via decontamination from microorganisms present in air, water, food, instruments and surfaces of animal farming systems. Furthermore, NTP is used in the treatment of waste water, vaccine production, wound healing in animals, odor-free ventilation, and packaging of animal food or animal products. This review summarizes the recent studies of NTP which can be related to the infrastructure in animal husbandry.

Non-thermal plasma specifically kills oral squamous cell carcinoma cells in a catalytic Fe(II)-dependent manner

Oral cancer accounts for ~2% of all cancers worldwide, and therapeutic intervention is closely associated with quality of life. Here, we evaluated the effects of non-thermal plasma on oral squamous cell carcinoma cells with special reference to catalytic Fe(II). Non-thermal plasma exerted a specific killing effect on oral squamous cell carcinoma cells in comparison to fibroblasts. Furthermore, the effect was dependent on the amounts of catalytic Fe(II), present especially in lysosomes. After non-thermal plasma application, lipid peroxidation occurred and peroxides and mitochondrial superoxide were generated. Cancer cell death by non-thermal plasma was promoted dose-dependently by prior application of ferric ammonium citrate and prevented by desferrioxamine, suggesting the association of ferroptosis. Potential involvement of apoptosis was also observed with positive terminal deoxynucleaotidyl transferase-mediated dUTP nick end labeling and annexin V results. Non-thermal plasma exposure significantly suppressed the migratory, invasive and colony-forming abilities of squamous cell carcinoma cells. The oral cavity is easily observable; therefore, non-thermal plasma can be directly applied to the oral cavity to kill oral squamous cell carcinoma without damaging fibroblasts. In conclusion, non-thermal plasma treatment is a potential therapeutic option for oral cancer.

Plasma cupping induces VEGF expression in skin cells through nitric oxide-mediated activation of hypoxia inducible factor 1

Despite a long history, the clinical efficacy of cupping therapy is still under debate. This is likely due to the lack of direct evidence for the biological actions of cupping, since the short exposure of cells to vacuum condition rarely has affects cellular activity. In this study, the medicinal properties of a recent medical technology, non-thermal plasma, were added to classical cupping and designated as 'plasma cupping' (PC). In our results, the plasma-generating efficacy was increased under a cupping-like semi-vacuum condition (410 Torr) rather than normal atmospheric pressure (760 Torr). Notably, while cupping rarely affects the angiogenic factor vascular-endothelial growth factor (VEGF)-A, the PC treatment on HaCaT human keratinocytes significantly induced the expression of VEGF-A. The increased expression of the VEGF-A gene after the PC treatment was expected to be a result of PC-mediated ERK protein activation. The PC-mediated activation of ERK was essential for the activity of hypoxia inducible factor (HIF) 1 alpha, which is responsible for the PC-mediated expression of VEGF-A. The PC mediated increase of NO in the media was thought as a main reason for the elevated HIF-1 protein activity. In addition to the angiogenesis-promoting action of PC, it also showed anti-inflammatory activity by reducing TNF-α-mediated IL-1β and IL-6 expression. Taken together, this study indicates the potential for PC that could enhance the clinical efficacy of cupping by adding the effects of non-thermal plasma to traditional cupping.

Prevention of bacterial colonization on non-thermal atmospheric plasma treated surgical sutures for control and prevention of surgical site infections

Surgical site infections have a remarkable impact on morbidity, extended hospitalization and mortality. Sutures strongly contribute to development of surgical site infections as they are considered foreign material in the human body. Sutures serve as excellent surfaces for microbial adherence and subsequent colonization, biofilm formation and infection on the site of a surgery. Various antimicrobial sutures have been developed to prevent suture-mediated surgical site infection. However, depending on the site of surgery, antimicrobial sutures may remain ineffective, and antimicrobial agents on them might have drawbacks. Plasma, defined as the fourth state of matter, composed of ionized gas, reactive oxygen and nitrogen species, free radical and neutrals, draws attention for the control and prevention of hospital-acquired infections due to its excellent antimicrobial activities. In the present study, the efficacy of non-thermal atmospheric plasma treatment for prevention of surgical site infections was investigated. First, contaminated poly (glycolic-co-lactic acid), polyglycolic acid, polydioxanone and poly (glycolic acid-co-caprolactone) sutures were treated with non-thermal atmospheric plasma to eradicate contaminating bacteria like Staphylococcus aureus and Escherichia coli. Moreover, sutures were pre-treated with non-thermal atmospheric plasma and then exposed to S. aureus and E. coli. Our results revealed that non-thermal atmospheric plasma treatment effectively eradicates contaminating bacteria on sutures, and non-thermal atmospheric plasma pre-treatment effectively prevents bacterial colonization on sutures without altering their mechanical properties. Chemical characterization of sutures was performed with FT-IR and XPS and results showed that non-thermal atmospheric plasma treatment substantially increased the hydrophilicity of sutures which might be the primary mechanism for the prevention of bacterial colonization. In conclusion, plasma-treated sutures could be considered as novel alternative materials for the control and prevention of surgical site infections.

MicroRNA-7450 regulates non-thermal plasma-induced chicken Sertoli cell apoptosis via adenosine monophosphate-activated protein kinase activation

Non-thermal plasma treatment is an emerging innovative technique with a wide range of biological applications. This study was conducted to investigate the effect of a non-thermal dielectric barrier discharge plasma technique on immature chicken Sertoli cell (SC) viability and the regulatory role of microRNA (miR)-7450. Results showed that plasma treatment increased SC apoptosis in a time- and dose-dependent manner. Plasma-induced SC apoptosis possibly resulted from the excess production of reactive oxygen species via the suppression of antioxidant defense systems and decreased cellular energy metabolism through the inhibition of adenosine triphosphate (ATP) release and respiratory enzyme activity in the mitochondria. In addition, plasma treatment downregulated miR-7450 expression and activated adenosine monophosphate-activated protein kinase α (AMPKα), which further inhibited mammalian target of rapamycin (mTOR) phosphorylation in SCs. A single-stranded synthetic miR-7450 antagomir disrupted mitochondrial membrane potential and decreased ATP level and mTOR phosphorylation by targeting the activation of AMPKα, which resulted in significant increases in SC lethality. A double-stranded synthetic miR-7450 agomir produced opposite effects on these parameters and ameliorated plasma-mediated apoptotic effects on SCs. Our findings suggest that miR-7450 is involved in the regulation of plasma-induced SC apoptosis through the activation of AMPKα and the further inhibition of mTOR signaling pathway.

Increment of growth factors in mouse skin treated with non-thermal plasma

Non-thermal plasma (NTP) has several beneficial effects, and can be applied as a novel instrument for skin treatment. Recently, many types of NTP have been developed for potential medical or clinical applications, but their direct effects on skin activation remain unclear. In this study, the effect of NTP on the alteration of mouse skin tissue was analyzed. After NTP treatment, there were no signs of tissue damage in mouse skin, whereas significant increases in epidermal thickness and dermal collagen density were detected. Furthermore, treatment with NTP increased the expression of various growth factors, including TGF-α, TGF-β, VEGF, GM-CSF, and EGF, in skin tissue. Therefore, NTP treatment on skin induces the expression of growth factors without causing damage, a phenomenon that might be directly linked to epidermal expansion and dermal tissue remodeling.