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Plasma medicine is an emerging and innovative interdisciplinary research field combining biology, chemistry, physics, engineering, and medicine. However, the safe clinical application of cold atmospheric plasma (CAP) technology is still a challenge. Here, we examine the use of aluminum (Al) foam with three pores-per-inch (PPI) ratings in clinical plasma applications. Al foams can filter sparks to avoid damage from high voltage discharge during surgery and efficiently deliver reactive species generated in CAP to the target. The sparks appear and plasma intensity increases at the foam/discharge interface, which just slightly increases the interface temperature without changing the interface microstructure during a 30-minute treatment. After CAP penetrated the Al foams, N2, N2+, *OH, O, and He emission peaks were characterized, and the highest values appeared using Al foams with 10 PPI. CAP with and without Al foam intermediating was used to treat deionized water, and the results indicate CAP in combination with 10 PPI Al foam led to much higher ROS concentration than CAP alone. For melanoma cell experiments, CAP with and without Al foam had a similar effect on cell viability after 30-second treatment, while CAP with the 10-PPI Al foam had much higher killing efficiency than CAP alone after 60-second treatment. In summary, 10-PPI Al foam can not only prevent damage to tissues resulting from high discharge voltage during clinical surgery but also increase the delivery efficiency of reactive species generated in plasma for biomedical applications.

In recent years, cold atmospheric plasma (CAP) using inert gas has been successfully applied for biomedicine, such as sterilization, wound healing, skin diseases, and tumor treatment. Here, we reported air cold atmospheric plasma with three different patterns (I. Non: basic square grid structure; II. Square: basic square grid structure + square node; III. Circle: basic square grid structure + circle node) for anaplastic squamous cell carcinoma treatment (VX2 cell line). Various plasma diagnostic techniques were applied to evaluate the physics of air CAP with patterns such as discharge voltage, plasma initial generating process, plasma temperature, and optical emission spectroscopy (OES). The direct effects of air CAP with patterns on anaplastic squamous cell carcinoma treatment (VX2 cell line) were investigated in vitro. We also studied the ROS (reactive oxygen species) and RNS (reactive nitrogen species) generation in cultured media released from VX2 cells after the treatment of air CAP with patterns. The results showed that the air CAP with circle-pattern generated more active substances during at 60s treatment time, which resulted in a higher death rate of VX2 cells. These initial observations establish the air CAP with patterns as potential clinical applications for cancer therapy.

Cold atmospheric plasma (CAP) displays antimicrobial, antitumor, and antiviral properties, while the underlying mechanism is seldom clearly elucidated. In this work, we employed CAP with air-feeding gas to directly inactivate SARS-CoV-2. The results indicate that the typical SARS-CoV-2 morphological spikes disappeared after plasma treatment and the proteosomes of SRAS-CoV-2 were modified. In addition, we also evaluated the safety of the air plasma device in simulating daily life environments through rat experiments. We evaluated rats' daily physiological behavior, body weight, food consumption, organ histopathology, blood biochemical indicators, and so on. These results demonstrate air plasma device is a safe and effective mean prevents virus transmissions and infections.

Plasma activated medium, containing reactive oxygen species (ROS) and reactive nitrogen species (RNS), has been used for cancer treatment as an indirect treatment method. Here we report cold atmospheric plasma (CAP) activated deionized (DI) water using helium (He), argon (Ar), and nitrogen (N2) as feeding gas for the cancer therapy. Basic characteristics of CAP activated DI water with different feeding gases were diagnosed and the effects of three solutions on the breast cancer cells and gastric cancer cells were also recorded. Our findings show that DI water treated by CAP with He feeding gas has a much stronger effect on apoptosis in precultured breast cancer cells and gastric cancer cells. These results are attributed to the higher concentration of ROS generated in CAP-activated DI water using He as feeding gas.

The self-organized pattern (SOP) phenomenon is prevalent in plasma, while knowledge about SOP discharge affecting reactive species generated plasma-activated media (PAM) for cancer therapy is poorly documented. The aim of this study focused on the effect of SOP discharge modes on reactive oxygen and nitrogen species (ROS, RNS) in He SOP plasma-activated media with different conductivity (saline solution and deionized (DI) water), and employed them to breast cancer MDA-MB-231 and pancreatic BxPC-3 cancer cells. Optical emission spectrum and Fluorimetric analysis were used to identify and quantify ROS and RNS generated in He SOP plasma-activated saline solution and DI water. Furthermore, He SOP plasma discharge modes are capable of efficiently controlling the ROS and RNS concentration in the plasma-activated saline solution and DI water, which contribute to the cytotoxic effect. On the other hand, stainless steel and copper were used as a lower electrode to compare their effect on cell viability. Taken together, our findings provide insight into potential mechanisms involved in cell death after treatment with He SOP plasma-activated media.

Micro-sized cold atmospheric plasma (uCAP) has been developed to expand the applications of CAP in cancer therapy. In this paper, uCAP devices with different nozzle lengths were applied to investigate effects on both brain (glioblastoma U87) and breast (MDA-MB-231) cancer cells. Various diagnostic techniques were employed to evaluate the parameters of uCAP devices with different lengths such as potential distribution, electron density, and optical emission spectroscopy. The generation of short- and long-lived species (such as hydroxyl radical (.OH), superoxide (O2-), hydrogen peroxide (H2O2), nitrite (NO2-), et al) were studied. These data revealed that uCAP treatment with a 20 mm length tube has a stronger effect than that of the 60 mm tube due to the synergetic effects of reactive species and free radicals. Reactive species generated by uCAP enhanced tumor cell death in a dose-dependent fashion and was not specific with regards to tumor cell type.

The electrochemical behavior and mechanical properties of friction stir welded AA5086 and AA6061 Al alloys were investigated. Micro-hardness measurements and tensile tests showed that the heat-affected zone (HAZ) in AA6061 had minimum hardness value (i.e., 88 HV) and served as failure site in the dissimilar weld. Corrosion testing revealed that the minimum value of Icorr appeared in the HAZ 5086 (0.54 uA/cm2) and HAZ 5086 was most resistant to corrosion. The AA 5086 side of the weld showed better corrosion resistance than the AA 6061 side., Comment: arXiv admin note: substantial text overlap with arXiv:1511.05507

Experiments have revealed a nontrivial cancer-inhibiting capability of liquid media treated by the plasma jet capable of forming thinly stratified self-organized patterns at a plasma-liquid interface. A pronounced cancer depressing activity towards at least two kinds of human cancer cells, namely breast cancer MDA-MB-231 and human glioblastoma U87 cancer lines, was demonstrated. After a short treatment at the thinly stratified self-organized plasma-liquid interface pattern, the cancer inhibiting media demonstrate well pronounced depression and apoptosis activities towards tumor cells, not achievable without interfacial stratification of plasma jet to thin (of several um) current filaments, which therefore play a pivotal (yet still not completely clear) role in building up the cancer inhibition properties. Moreover, thinly stratified, self-organized interfacial discharge is capable to efficiently control the ROS and RNS concentrations in the cancer-inhibiting media, and in particular, abnormal ROS/RNS ratios not achievable in discharges which do not form stratified thin-filament patterns could be obtained. These results were explained in terms of interaction of thin plasma filaments of the self-organized pattern with gas and liquid, where the unusual interaction conditions (i.e., high surface-to-volume ratios etc.) cause accumulation of ROS, RNS and other species in unusual ratios and concentrations, thus forming potentially efficient anti-cancer cocktail. Our funding could be extremely important for handling the cancer proliferation problem, and hence, it should be brought to light to attract due attention of the researchers and explore the possible potential of this approach in tackling the challenging problem of high cancer-induced mortality and rising morbidity trends.

Cold atmospheric plasma (CAP) was shown to affect cells not only directly, but also indirectly by means of plasma pre-treated solution. This study investigated a new application of CAP generated in deionized (DI) water for the cancer therapy. In our experiments, the CAP solution was generated in DI water using helium as carrier gas. We report on the effects of this plasma solution in breast (MDA-MD-231) and gastric (NCI-N87) cancer cells. The results revealed that apoptosis efficiency was dependent on the plasma exposure time and on the levels of reactive oxygen and nitrogen species (ROS and RNS). The plasma solution that resulted from 30-minute treatment of DI water had the most significant effect in the rate of apoptosis., Comment: arXiv admin note: text overlap with arXiv:1605.05345

Non-thermal atmospheric plasma (NTAP) can be applied to living tissues and cells as a novel technology for cancer therapy. Even though studies report on the successful use of NTAP to directly irradiate cancer cells, this technology can cause cell death only in the upper 3-5 cell layers. We report on a NTAP argon solution generated in DI water for treating human gastric cancer cells (NCl-N87). Our findings showed that the plasma generated in DI water during a 30-minute treatment had the strongest affect in inducing apoptosis in cultured human gastric cancer cells. This result can be attributed to presence of reactive oxygen species (ROS) and reactive nitrogen species (RNS) produced in water during treatment. Furthermore, the data showed that elevated levels of RNS may play an even more significant role than ROS in the rate of apoptosis in gastric cancer cells., Comment: arXiv admin note: text overlap with arXiv:1607.06775

Cold atmospheric plasma (CAP) has been emerged as a novel technology for cancer treatment. CAP can directly treat cells and tissue but such direct application is limited to skin or can be invoked as a supplement during open surgery. In this study we report indirect plasma treatment using CAP discharged in DI water using three gases as carriers (argon, helium and nitrogen). Plasma stimulated water was applied to human breast cancer cell line (MDA-MB-231). MTT assay tests showed that using argon plasma had the strongest effect on inducing apoptosis in cultured human breast cancer cells. This result is attributed to the elevated production of the reactive oxygen species and reactive nitrogen species in water in the case of argon plasma., Comment: arXiv admin note: text overlap with arXiv:1607.06775

The microstructure, mechanical properties, and corrosion behavior of friction stir welded (FSW) AA6061 aluminum alloys were investigated. Dynamic recrystallized structures were observed and grain sizes of nugget zone (NZ), thermomechanically-affected zone (TMAZ), heat-affected zone (HAZ), and base material (BM) were different. Hardness test indicated that the minimum and maximum hardness values wereobtained in the HAZ and BM, respectively. Tensile results showed that fracture occurred in the relatively weak regions in between TMAZ and HAZ. Polarization tests illustrated that the FSW process improved the corrosion resistance of AA6061-AA6061 and the HAZ had better corrosion resistance than other regions. Raman characterizations revealed that aluminum hydroxide was the main corrosion product formed on Al after immersion experiments. Intergranular attack was observed in the NZ and downside by scanning electron microscopy., Comment: arXiv admin note: text overlap with arXiv:1511.04990