The Neuroprotective Application Of Atmospheric Pressure Plasmas Jets

Atmospheric pressure plasma jet?APPJ?is a novel low temperature plasma technology developed in recent years.It can be widely used for material surface treatment and biomedicine due to its unique advantages such as low gas temperature and high concentration of active particles,free of vacuum system,etc.Biomedical applications based on APPJ has become a hot topic around world,including the induction of tumor cell apoptosis,sterilization,wound healing and promotion blood coagulation.However,there was no direct evidence to prove the protective effect of APPJ on neurons.In the present study,a needle-to-ring DBD?dielectric barrier discharge?driven by alternating voltage is used to produce the APPJ,and SH-SY5Y cells are treated by plasma jet under different conditions.By studying the change of cell viability?cell apoptosis and the content of NO to study the neuroprotective function of plasma.Firstly,the influence of the applied voltage,driving frequency and helium flow on the plasma jet investigated experimentally.The results show that the jet length increases firstly and then tends to be unchanged at increasing voltage and flow rate in a certain range.The OES?optical emission spectra?shows that there exist many active particles in the jet including N₂⁺,N₂,O and so on.These species may play a double-edged-sword role in biomedical applications.Then,under the parameters,cells were treated for 0-10 s and cultured for 16 hours.Then the cells were injured by 200?M H₂O₂ and the extracellular NO concentration was further assayed using the Greiss reagent.After 24 hours,the activity of cells were tested by CCK-8?Calcein-AM assay?Annexin-V/PI staining assay,respectively.The results showed that with the increase of plasma treatment time,the content of NO increased significantly;0-8s plasma treatment can improve the cell activity and reduce the cell damage caused by H₂O₂,but when the treatment time was up to 10s,plasma increased cell injuries caused by H₂O₂ treatment.1.4slm gas treatment group had no obvious effect on cell injury induced by H₂O_2.At the same time,the plasma did not induce significantly SH-SY5Y proliferation,indicating that the increased cell viability after H₂O₂exposure was not due to the cell proliferation induced by plasma but for the neuroprotective effect of low dose plasma treatment.Since the low dose of NO has neuroprotective function in physiological state,we hypothesized that the neuroprotective function of plasma is related to RNS and NO.