Research Based On Atmospheric Pressure Plasma Plume Effects To Cancer Cells And Its Mechanism

Recently, biomedical applications of plasmas are becoming one of the hotspots in the plasma application research area. More and more new types of plasma generation devices are used to modify the structure and function of cells and human tissues, like using plasma to kill various kinds of bacteria(escherichia coli, staphylococcus aureus, et al)in the medical equipments'sterilization process, treating cell culture plates with plasma to control cell proliferation in cell engineering, using plasma to promote wound healing in surgery. These studies are mostly focus on the design of new type plasma generation devices. The objects they treated are mostly bacteria and chemical materials. However the roles of atmospheric pressure plasma play to cancer cells are not well studied. In this artical, we investigate from the biochemical angle, preliminary studied the mechanism of cancer cells killed by atmospheric pressure plasma, and initially hope to find the plasma particle compositions that play major role to cancer cells. Moreover, we have detected some intracellular physical and chemical changes caused by plasma.Firstly we studied the discharge characteristics of plasma jet decives and measured the optical emission of the plasma plume. Then, human hepatocellular carcinoma cell (HepG2),melanoma cel(lB16)and prostate cancer cel(lPC3)were chose as biological model to investigate atmospheric pressure plasma's biochemistry effects on them. We detected that plasma induced cancer cells'death, found that plasma could inhibit various cancer cells'proliferation. Furthermore we got the proper plasma treatment condition, which could kill more cancer cells at the least plasma consumed. Finally human hepatocellular carcinoma cells(HepG2)were treated by plasma and studied the biochemical changes of cancer cells after plasma treatment. We detected the activity of mitochondrial succinate dehydrogenase, cell morphology conditions'changes, the intracellular levels of NOS and ROS, DNA structure and gene's changes et al. From these results we analyzed the reason of cancer cells'death after plasma treatment, derived the mechanism of plasma induced cancer cells'death. The activity particles of the plasma could induce the intracellular levels of NOS and ROS rose, the intracellular free radicals'balance would be broken down afterward, and finally a large number of cancer cells would be lead to death. The study also found out that plasma could cause some changes to the conformation of DNA: from the supercoiled structure into the linearized and open circular structure, which would improve the success rate of transformation frequency. The plasma has a great potential application in genetic engineering.