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Atmospheric pressure cold plasmas are widely used in the biomedical field as evidenced by developments in recent years. In this study, a quartz tube-guided gas–liquid two-phase discharge has been configured with a hollow needle-water structure. The power source for the device was sinusoidal, and switching between a gas–liquid miscible discharge and a pure gaseous discharge was simple. It was discovered that the gas–liquid discharge was beneficial in terms of reactant species generation and reaction efficiency in terms of processing water. The types of particles, the physicochemical properties, and the concentrations of reactive oxygen and nitrogen species in the discharge were studied spectroscopically. The discharge was discovered to have high levels of H2O2 and NO2−, and the activated water was proven to be effective at sterilizing samples that were contaminated with micro-organisms. Key experimental parameters including the driving voltage and the air flow rate were optimized to achieve the best sterilization conditions. The membrane potential changes in the treated bacteria were also studied to explore the causes of bacterial inactivation. The results showed that the device exhibited a strong bactericidal effect for the gas–liquid mixed phase discharge operating at 17 kV for 5 min with a gas flow rate of 0.3 SLM. In addition, the present device offers enhanced sterilization efficiency relative to the efficiency of conventional plasma sterilization equipment and, therefore, has a wide range of applications. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) is the second most common hematologic malignancy. MM stem cells (MMSCs) are thought to be the main causes of in vivo engraftment and eventual recurrence. As a notable new technology, cold atmospheric plasmas (CAPs) show a promising anti-tumor effect, due to their production of various ROS. In this study, we found that different types of plasma could inhibit MM's ability to form cell colonies, suppress MM in vivo engraftment, and extend survival times. We demonstrated that NAC (a ROS scavenger) could block ROS increases and reverse the inhibition of MM's cell-colony-formation ability, which was induced by the plasma treatment. By using a stem cell signaling array, we found that the Notch pathway was inhibited by the plasma treatment; this was further confirmed by conducting real-time PCRs of three MM cell lines. Together, these results constitute the first report of plasma treatment inhibiting MM in vivo engraftment and prolonging survival time by suppressing the Notch pathway via ROS regulation. [ABSTRACT FROM AUTHOR]

Violet phosphorus (VP) has emerged as the most stable and biocompatible allotrope of phosphorus. Our study first reported the synergistic anti-cancer effects by combination treatment of violet phosphorene nanosheets (VPNS) and cold atmospheric plasma (CAP) in vitro and in vivo. VPNS-1 exhibited remarkable efficacy in inhibiting tumor growth by suppressing arachidonic acid metabolism, while CAP induced cancer cell apoptosis through the increase of reactive oxygen species (ROS). Moreover, the key role played by AKT and anti-apoptotic proteins of the Bcl-2 family (Bcl-2, Bcl-xL, and Mcl-1) in the induction of apoptosis in VPNS-CAP treatment was demonstrated. Our combination therapy just like "tai chi", controlling cancer cell growth and death with low or no side effect. [Display omitted] • VPNS-1 and CAP have synergistic anti-cancer effects by in vitro and in vivo. • VPNS-1 inhibit tumor growth by suppressing arachidonic acid metabolism in vivo. • AKT, Bcl-2, Bcl-xL and Mcl-1inhibition by co-treatment to induce cell apoptosis. • VPNS-1 and CAP treatment show low or no side effects in vivo. Violet phosphorene nanosheets (VPNS), another type of two-dimensional nonmetal nanostructure, is a promising nanomaterial for biomedical applications. Cold atmospheric plasma (CAP) is an emerging anti-cancer strategy. Here, for the first time, a synergistic combination of VPNS and CAP exhibited remarkable efficacy in cancer treatment. Our findings revealed that VPNS and CAP effectively suppress cancer cell viability by inhibiting cell proliferation and inducing cell apoptosis in vitro. Moreover, we demonstrated the synergistic anti-cancer effect of VPNS and CAP in vivo , with low or no side effects. By metabolism analysis in vivo , we first reported that VPNS-1 inhibited tumor growth by down-regulating Delta-12-Prostaglandin J2, 8,9-DiHETrE, and Hepoxilin B, thereby suppressing arachidonic acid metabolism. Additionally, the down-regulation of AKT and anti-apoptotic proteins (Bcl-2, Bcl-xL and Mcl-1) of Bcl-2 family contributed to the inhibition of cell growth and the initiation of cell apoptosis. Our results unveiled a novel and promising anti-cancer approach involving the combined treatment of VPNS and CAP. [ABSTRACT FROM AUTHOR]