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The behaviors of atmospheric pressure plasma jet produced by a coplanar dielectric barrier discharge (CDBD) in helium in external electrostatic and magnetic field are investigated experimentally. Time-resolved ICCD images of jet in electric field, magnetic field, and floating metal ring are recorded, respectively. The results show that the jet dynamics is affected significantly by a metal ring, an electric, and/or a magnetic field. In a transverse electric field, the jet shows behavior of deflection, broadening, and shortening according to the structure of electric field. In a transverse magnetic field, the jet deflects to up or down depending on the magnetic direction. The jet can be slowed down or obstructed by a floating metal ring on the jet path, but will still pass through the tube at higher applied voltages of DBD, without significant change in jet length or shape out of the tube compared with that without metal ring. A positive DC voltage on the metal ring helps to improve the jet length, but a negative voltage will reduce the length or completely stop the jet. The electric field to sustain the jet in helium is estimated to be about 24 ± 15 kV/cm from this experiment. [ABSTRACT FROM AUTHOR]

Atmospheric pressure plasma jet (APPJ) has shown excellent potential prospects in biomedical applications, based on the production of reactive oxygen species and reactive nitrogen species (RNS) from APPJ emissions. The current research focused on the protective effect of APPJ on oxygen and glucose deprivation (OGD)-induced cell death in both the H9C2 cardiac myoblast cell line, a frequently used cardiac cell line in cardioprotective studies, and primary neonatal rat cardiomyocytes (NRCMs). Cells were treated with APPJ for different durations, cultured for 6 h and then subjected to OGD for 18 h before their use in assays. We found that APPJ treatment could maintain H9C2 cell viability and reduce cell apoptosis in a dose-dependent manner in cells subjected to the OGD conditions. To confirm the cardioprotective effect of APPJ on primary NRCM, we first identified the ‘safe dose’ of APPJ treatment by evaluating the cytotoxicity of APPJ on primary NRCMs in normal culture conditions. Under the ‘safe dose’ of APPJ treatment, we also found that the APPJ treatment could maintain NRCM viability under OGD conditions and reduce CK-MB and cTnI release from cardiomyocytes. Further studies revealed that the cytoprotective effect of APPJ may be related to NO production induced by APPJ treatment. Our results gave the first evidence of the cardiotoxicity and cytoprotective effect of APPJ on cardiomyocytes against OGD injury, and furthermore, contributed to new insights into the potential medical applications of plasma in cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Atmospheric pressure plasma jet (APPJ) has recently been the focus of cytoprotective research due to the physiological roles of ROS and RNS. In the current study, we investigated the effect of APPJ treatment on the hypoxia (1% oxygen) induced cell injuries. SH-SY5Y cells were treated by APPJ for different duration and incubated in normoxic condition (20% oxygen) for 5 h followed by 24 h hypoxia treatment. Cell viability was evaluated by lactate dehydrogenase (LDH) release and further monitored using the electric cell-substrate impedance sensing (ECIS) system after APPJ treatment. Results showed that APPJ could reduce cell injuries after 24 h hypoxia, which was consistent with the ECIS results. Furthermore, extracellular NO and H2O2 production was significantly increased with the APPJ treatment. It was also interesting to find that APPJ treatment reduced SH-SY5Y cells proliferation in the hypoxic microenvironment during the first 20 h of hypoxia. Although more work was still need to clarify whether the cell viability maintenance was related to the cell proliferation during hypoxia, our results provide the first evidence of real-time cell viability changes after APPJ treatment under both normoxic and hypoxic conditions, which could provide evidence for the neuroprotective applications of APPJ. [ABSTRACT FROM AUTHOR]