Study On The Action Mechanism Of Different Doses Of Atmospheric Pressure Low Temperature Plasma On Cells

Atmospheric pressure low temperature plasma(NTP)has been applied to many clinical diseases in recent years,such as the healing of acute and chronic wounds,oral therapy,cancer treatment and so on.Clinically,the prolonged treatment of chronic wounds such as venous ulcer,arterial ulcer,diabetic ulcer,traumatic ulcer and pressure ulcer will not only cause long-term physiological pain to the patients,but also cause the patients to bear great mental pressure.Numerous scholars are committed to the research on wound healing.At present,the traditional treatments for chronic wounds include herbal medicine therapy,growth factor cocktail therapy,and skin stem cell(stem cells such as fibroblasts,keratinocytes,and vascular endothelial cells)transplantation therapy.There are many methods,but the limitation for the treatment of chronic wounds still exists in large numbers.For example,drug resistance brought by long-term drug therapy,complex and expensive operation of growth factors and stem cell transplantation therapy,and the financial burden borne by patients are hard to bear.Therefore,new and effective treatment methods for clinical chronic wounds urgently need to be developed.The extensive application of atmospheric pressure low temperature plasma in biomedicine in recent years has given us new inspiration.In addition,for clinically undifferentiated thyroid cancer,although it is very rare for thyroid cancer categories,the clinical mortality rate is as high as 50% or more due to its characteristics of easy metastasis and rapid progress.Traditional radiotherapy,chemotherapy and targeted therapy have their own limitations,so a new and effective treatment is urgently needed.The atmospheric pressure cryogenic plasma also has this cancer therapeutic effect.The reason why low-temperature plasma can be applied not only to wound healing but also to the killing of cancer cells is that the different doses of ROS(reactive oxygen species)produced by it can act on cells to produce completely different biological effects:proliferation,differentiation,apoptosis and even focal death.Therefore,according to the characteristics of low-temperature plasma,we have designed two topics: 1.Low-dose low-temperature plasma promotes chronic wound healing by promoting normal human skin cells;2.High-dose and low-temperature plasma inhibits the progression of cancer by inhibiting the growth of thyroid undifferentiated cancer cells.First,we investigated the effects of low-dose non-thermal atmospheric plasma(NTP)on the proliferation and migration of human immortalized keratinocytes(HaCaT cells)and its molecular mechanisms.To investigate the role of ROS content in low-dose NTP by measuring cell viability,wound healing test,cell cycle,mitochondrial membrane potential and Western Blot.The results showed that the cell proportion at the G1-S phase transition point,cell migration ability,and Cyclin D1 and STAT3 expressions all reached the peak in the 10-S treatment group,while the cell viability and PI3K,AKT,mTOR,ERK,WNT and β-catenin protein expressions all reached the peak in the 15-S treatment group.These results indicated that ROS produced by low-dose NTP promoted the proliferation of HaCaT cells by activating the PI3K/AKT/mTOR signaling pathway,and promoted cell migration by activating the WNT/β-catenin signaling pathway.Therefore,these results will facilitate the use of low-dose NTP in wound healing therapy.Secondly,we investigated the mechanism of high-dose non-thermal plasma inhibiting the growth of undifferentiated thyroid cancer cells(CAL-62 cells);The morphological changes,cell survival rate experiment,extracellular active oxygen and active nitrogen detection,intracellular mitochondrial membrane potential detection,and cell migration ability detection under a microscope were used to explore the effect of high dose on CAL-62 cells.The results showed that after 30 s NTP treatment,CAL-62 cells contracted and became round,with obvious morphological changes.The migration ability of cell viability cells was significantly inhibited,and the mitochondrial membrane potential of cells was significantly decreased.ROS and RNS of cultured cells increased significantly after treatment with NTP.These results indicated that high-dose NTP treatment could significantly inhibit the growth of thyroid undifferentiated cancer cells and induce their early apoptosis,which would provide certain theoretical support for the clinical treatment of undifferentiated thyroid cancer.In summary,ROS generated by low-temperature plasma at different doses can act on different cells to exert different biological effects,namely,low-dose NTP promotes wound healing by promoting the proliferation and migration of normal human skin cells,and high-dose NTP inhibits the progression of undifferentiated thyroid cancer by inhibiting the growth of thyroid undifferentiated cancer cells.