低温等离子体对小鼠皮肤伤口愈合的影响
Effect of low-temperature plasma on wound healing of mouse skin

摘要：目的 比较不同剂量的大气压低温等离子体对BALB/c小鼠伤口愈合的影响，探讨低温等离子体处理小鼠伤口的最佳剂量以及影响伤口愈合的机制。方法 采用介质阻挡放电方法产生大气压低温等离子体射流，对小鼠皮肤伤口进行处理，按处理时间分为10s、20s、30s、40s、50s实验组，以不处理的自然愈合的伤口作为阴性对照组，以人重组表皮生长因子处理伤口作为阳性对照组，每天处理1次，连续观察14d。每天记录各组的伤口尺寸变化；取处理第7天的伤口组织行HE染色观察组织病理学变化；免疫荧光染色技术检测伤口组织中Ⅰ型胶原蛋白的表达；发射光谱分析低温等离子体射流的成分。结果 10s、20s、30s、40s实验组的小鼠伤口愈合速度较快，分别在第12、10、7、13天均基本愈合，而50s实验组的小鼠伤口在第14天尚未愈合；阳性对照组的小鼠伤口在第7天全部愈合，30s实验组可以达到阳性对照组小鼠伤口愈合效果。HE染色与免疫荧光染色技术表明，30s的等离子体处理剂量可以最大限度的促进伤口表皮再生，肉芽组织增生和胶原沉淀。光谱诊断发现低温等离子体中含有OH、NO、激发态N？？2分子以及激发态O原子。结论 适量的低温等离子体可促进小鼠的伤口愈合，而过量则会抑制小鼠伤口的愈合；伤口的愈合过程可能和低温等离子体中的活性氧、活性氮的作用相关。
ABSTRACT: Objective To compare the different doses of low-temperature plasma (LTP) on wound healing in BALB/c mice so as to discuss the effects of the optimal dose of low-temperature plasma dealing with wound in mice and the acting mechanism of wound healing. Methods Adoptatmospheric pressure plasma jet discharged by the dielectric barrier was used to treat mouse skin wound. According to the processing time, the wounds were divided into 10s, 20s, 30s, 40s and 50s experimental groups, while naturally healing wounds served as negative controls and the wounds dealt with recombinant human epidermal growth factor served as positive controls. We recorded the wound size every day, observed the histopathological changes, the expression level of type Ⅰ collagen by immunofluorescence, and analyzed the composition of low-temperature plasma jet. Results The wounds with plasma treatment time of 10s, 20s, 30s, and 40s showed significant daily improvement and almost complete closure at days 12, 10, 7, 13, respectively. However, the wounds with plasma treatment time of 50s remained unhealed at day 14. The wounds in positive control group all healed, and the wound healing effect in positive control group could be achieved in 30s group. HE staining and immunofluorescence staining assays showed the optimal result of epidermal cell regeneration, granulation tissue hyperplasia, and collagen deposition in histological aspect at day 7 in 30 s group. The low-temperature plasma jet contained highly reactive free radicals of nitrogen and oxygen, which play an important role in wound healing process. Conclusion Appropriate doses of cold plasma can accelerate wound healing whereas over-doses of plasma can suppress wound healing. The process of wound healing may be related to reactive oxygen and nitrogen species in LTP