纳米银( AgNP)是指粒子直径在1~100 nm的金属银单质,现已广泛应用于多个领域。研究发现,AgNP的毒性特征与其粒径大小有一定的关系,粒径越小,毒性越强,一般来说20 nm左右毒性最强。进入机体后在体内各器官均有分布,但浓度有明显差异,有的在肾脏中还表现出性别差异。AgNP进入生物机体各器官会产生一定的毒性效应。 AgNP对体外细胞的毒性往往表现出剂量效应,而体内实验中,其毒性效应会随着作用对象及作用方式的不同而不同。此外, AgNP还会产生一定的生殖毒性,使亲代生殖特性降低,并可通过母体胎盘传递到子代体内,对子代的生长发育造成一定的影响。 AgNP毒性作用机制主要通过产生自由基导致器官的氧化应激损伤；药酶代谢活力降低导致代谢障碍；亦有相关基因表达的缺陷,及某些分子如转录因子NF-E2相关因子2(Nrf2)所致的蛋白酶表达异常。总之,AgNP可对生物有机体产生毒性,我们在应用的同时要对其生物安全性进行评价,最大程度地减少甚至避免其对我们的损害。%Silver nanoparticles ( AgNP) , the metallic silver par-ticles with the diameter of 1 ~100 nm are now widely used in many fields. Many researches show that the smaller size of Ag-NP, the stronger toxicity it shows. Generally speaking, AgNP with 20 nm shows strongest toxicity. After entering the body, they are distributed in different organs in the body, and the dis-tribution in the kidney shows a certain gender difference. They also produce some toxic effects after entering body organs. AgNP often exhibit dose effect on the toxicity in vitro cells,while in vivo experiments, their toxic effects change with the different objects and ways of acting. In addition, AgNP can produce toxic effects on reproduction, and may cause parental reproductive activity to deteriorate, and pass the toxic effects to offspring through the placenta to exert a negative influence on the growth and develop-ment of the offspring. The toxicity mechanisms of AgNP are oxi-dative stress injury caused by producing free radicals;metabolic disorders caused by reducing of drug metabolic enzyme activity;and also related gene expression defects and certain molecules, such as transcription factor NF-E2-related factor 2(Nrf2) prote-ase caused by abnormal expression. In short, AgNP can be toxic to organisms, and we must evaluate their biological safety when we use it, to minimize or even avoid the danger it brings about.
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