纳米铜对家蚕的生物效应及其作用机制

发布时间：2018-05-06 09:15

本文选题：家蚕 + Cu纳米颗粒　；参考：《江苏科技大学》2016年硕士论文

【摘要】：随着纳米材料的广泛应用,越来越多的纳米产品进入到人们的生活中,极大的增加了其曝露于人体的机会。纳米铜是一种常用的金属纳米材料,由于其特殊的物理化学特性,被广泛的应用在各领域。纳米铜的广泛应用已引起了人们对其生物安全性的关注,目前关于纳米铜毒性效应的研究较少,其毒性机制尚不明确,同时纳米铜的毒性试验大都是以成本高、伦理道德争议多的高级动物作为模型动物进行的,为了解决上述实验中存在的问题并对纳米铜的生物安全性评价提供理论依据,寻找一种成本低、争议少、对纳米材料反应灵敏的模型动物来研究纳米铜的生物毒性显得尤为重要。本研究以五龄家蚕作为模型动物,通过第二腹足注射曝露染毒,在200μg/头剂量下研究纳米铜对家蚕的毒性效应和作用机制。实验主要研究内容和成果如下:1.分别给家蚕注射不同浓度的20 nm CuNPs悬浮液,通过曝露实验结果计算得到CuNPs对家蚕的48 h半致死剂量(LD50)为196.05μg/头,95%可置信区间为145.85?230.15μg/头,CuNPs的曝露会抑制家蚕生长,影响家蚕食欲,同时也会给家蚕体内组织带来一定的损伤,并呈现一定的时间效应和剂量效应。2.建立了微波消解-电感耦合等离子体质谱法检测CuNPs在家蚕各组织含量的方法,实验过程中Cu元素的标准曲线呈现良好的线性关系,空白组和实验组中相关系数分别为0.99945和0.99969,Cu元素的加标回收率在101%?106%之间,相对标准偏差RSD小于3.22%。实验结果表明CuNPs在进入到家蚕体内后会引起各组织中Cu元素的含量显著性的升高(p0.05),其中脂肪体、中肠、气管中Cu元素含量变化比较大,可能是CuNPs的主要靶器官。3.采用石蜡切片技术、TEM观测及EDS能谱对家蚕各组织的病理变化和CuNPs的存在形态进行了分析。结果表明CuNPs在进入到家蚕体内后会以原有的纳米颗粒状存在于家蚕各组织中,不但会破坏各组织自身的一些防御屏障对组织产生一些损伤,同时还会对家蚕各组织细胞产生一定的毒害。结果还发现,进入家蚕组织内的CuNPs会被一层生物分子所覆盖,但对于这一覆盖层的成分组成及相关的作用机理还不是很明确,需进一步的研究。4.在该曝露剂量下,CuNPs会对家蚕各组织产生一定的氧化损伤,表现为:家蚕各组织中ROS强度显著提升(p0.05),同时氧化损伤标志物脂质过氧化产物MDA均显著性提升(p0.05),DNA氧化产物8-OHdG水平也明显升高;CuNPs还会破坏家蚕各组织的抗氧化系统,表现为抗氧化酶SOD和CAT酶活性受到显著性的抑制;各组织中环磷酸腺苷(cAMP)表达量显著下降(p0.05)。5.在该曝露剂量下CuNPs会对家蚕各组织中细胞因子的表达产生一定的影响,破坏家蚕的免疫机制,并导致一系列的病变:各组织和血淋巴中半胱氨酸蛋白酶抑制剂(CysC)表达显著性上调(p0.05)、核转录因子-κB(NF-κB)表达显著性上调(p0.05)、免疫球蛋白(Ig)的分泌受到明显抑制(p0.05)、细胞凋亡因子(Fas)显著性上调(p0.05)。
[Abstract]:With the wide application of nanomaterials, more and more nanomaterials have entered people's lives and greatly increased their exposure to the human body. Nano copper is a kind of common metal nanomaterial. Because of its special physical and chemical properties, it has been widely used in the various domain. The wide application of nano copper has caused people to it. At present, there are few studies on the toxicity of nanoscale copper, and its toxicity mechanism is not clear. At the same time, the toxicity test of nanoscale copper is mostly based on high cost and ethical and moral disputes. In order to solve the problems in the experiment and evaluate the biosafety of nano copper, the toxicity of nano copper is not clear. It is very important to study the biological toxicity of nano copper by providing a theoretical basis, looking for a low cost and less controversial animal with sensitive reaction to nanomaterials to study the biological toxicity of nanoscale copper. In this study, five age silkworm was used as a model animal to study the toxicity and effect of nano copper on silkworm by injecting second gastropods and exposed to 200 mu g/ head. The main contents and results of the experiment are as follows: 1. the 20 nm CuNPs suspension of different concentration of silkworm was injected into the silkworm, and the 48 h semi lethal dose (LD50) of the silkworm (LD50) was 196.05 mu g/ head and 95% confidence interval was 145.85? 230.15 mu g/ head. The exposure of CuNPs to inhibit the growth of silkworm and affect the appetite of the silkworm. It also brings some damage to the tissues of silkworm, and presents a certain time effect and dose effect.2. to establish a method of microwave digestion inductively coupled plasma mass spectrometry to detect the content of CuNPs in the silkworm tissues. The standard curves of Cu elements in the experiment show a good linear relationship and the relationship between the blank group and the experimental group. The number of Cu elements was 0.99945 and 0.99969 respectively, and the recovery rate of the addition standard was 101%? 106%. The relative standard deviation RSD was less than 3.22%. experimental results showed that CuNPs could cause a significant increase in the content of Cu elements in the tissues of the silkworm (P0.05). The content of the Cu elements in the fat body, middle intestine and the trachea was relatively large, which may be CuNPs The main target organ of.3. was paraffin section technique, TEM observation and EDS spectrum analysis were used to analyze the pathological changes of the tissues of the silkworm and the existence form of CuNPs. The results showed that CuNPs would exist in the silkworm tissues in the silkworm body after entering the silkworm body, which not only destroyed some defense barrier pairs of the tissues themselves. It is also found that the CuNPs in the silkworm tissue will be covered by a layer of biomolecules, but the composition and the related mechanism of the covering layer are not very clear. It is necessary to study the.4. at the exposure dose of CuNPs. There were some oxidative damage in the tissues of the silkworm, which showed that the ROS intensity of the silkworm tissues increased significantly (P0.05), while the lipid peroxidation product MDA of the oxidative damage markers increased significantly (P0.05), and the 8-OHdG level of the DNA oxidation product increased obviously, and CuNPs also destroyed the antioxidant system of the silkworm tissues, which showed the antioxidant enzyme SOD and C. AT enzyme activity was significantly inhibited, and the expression of cAMP in each tissue decreased significantly (P0.05).5. at the exposed dose of CuNPs could affect the expression of cytokines in the tissues of the silkworm, destroying the immune mechanism of the silkworm, and causing a series of pathological changes: the inhibition of cysteine protease in the tissues and the hemolymph. The expression of CysC was significantly up-regulated (P0.05), the expression of nuclear factor kappa B (NF- kappa B) was significantly up-regulated (P0.05), the secretion of immunoglobulin (Ig) was significantly inhibited (P0.05), and apoptosis factor (Fas) was significantly up-regulated (P0.05).

【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X171.5;TB383.1

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