【作者】 白茹；

【导师】 宋文华；

【作者基本信息】 天津理工大学 ， 安全技术及工程， 2007， 硕士

【摘要】 纳米材料由于其独特的理化性质,且不能用常规的方法和手段进行检测,可能会对人体及生态环境造成污染,从而危及人类健康,因而有必要对其健康效应进行研究。本论文选用三种纳米材料,分别是应用较为广泛的纳米TiO₂、多壁碳纳米管（MWNT）和纳米铁颗粒。由于纳米颗粒主要通过呼吸系统进入人体,所以本实验主要研究纳米材料对生物体肺部的影响。采用非暴露式气管内注人法对昆明种（KM）小鼠染毒,所有材料的染毒剂量为10mg/kg bw和1mg/kg bw,生理盐水对照组小鼠每只注入0.1mL生理盐水,染毒三次,第十天处死小鼠,并进行肺泡灌洗,测定肺泡灌洗液（BALF）中的白细胞总数、乳酸脱氢酶（LDH）活力、羟脯氨酸酶（HYP）含量、肺脏器系数,对肺做病理切片观察,并对小鼠体重变化率进行比较,分别考察三种纳米材料各自的生物学效应,最后对三种纳米材料的生物学效应进行比较。通过实验得出如下结果:1.纳米TiO₂ 10mg/kg bw组体重增长率最低,其他各指标均高于对照组和纳米TiO₂ 1mg/kg bw组,差异显著（P<0.01或P<0.05）。纳米TiO₂ 10mg/kg bw组脏器系数、LDH活力、Hyp含量均高于常规TiO₂ 10mg/kg bw组,差异显著（P<0.01或P<0.05）;虽然纳米TiO₂ 10mg/kg bw组白细胞数目高于常规TiO₂ 10mg/kg bw组（7.47×105）,但差异无显著性。病理形态学观察结果显示,纳米TiO₂ 10mg/kg bw组引起肺部明显病变。2.MWNT 10mg/kg bw组体重增长率最低,其它各指标均高于对照组和纳米1mg/kg bw组,差异显著（P<0.01或P<0.05）,病理形态学观察结果表明,MWNT 10mg/kg bw组小鼠肺部损伤最重。3.纳米铁1mg/kg bw组增长率最低,其肺脏器系数、白细胞数目和羟脯氨酸含量均高于生理盐水对照组和纳米铁1mg/kg bw组,差异显著（P<0.01或P<0.05）。4.纳米TiO₂ 10mg/kg bw组LDH活力最高,MWNT 10mg/kg bw组HYP含量最高。纳米TiO₂ 10mg/kg bw组和MWNT 10mg/kg bw组均导致肺大泡形成和肺实变发生,但纳米TiO₂ 10mg/kg bw组使得小鼠肺呼吸性细支气管上皮消失,而MWNT 10mg/kg bw组只发现细支气管、呼吸性细支气管内有MWNT沉积,未发现上皮黏膜的损坏。对结果进行分析,得出如下结论:1相同的实验条件下,纳米级TiO₂比常规TiO₂更能引起严重的肺部急性损伤,纳米TiO₂高剂量对肺部损伤作用比低剂量组更加明显。2 MWNT对小鼠肺造成一定的急性损伤作用,并且其高剂量组各指标高于低剂量组,对生物体健康构成潜在威胁。3纳米铁对小鼠肺造成一定的急性损伤作用,并且其高剂量组各指标高于低剂量组,对生物体健康构成潜在威胁。4同剂量下纳米TiO₂、MWNT、纳米铁三种材料在体重变化率、LDH活力、HYP含量上存在显著差异,表明不同材料的纳米级颗粒物的肺毒性存在差异,作用机制也不相同。更多还原

【Abstract】 Because of unique physical chemistry quality and can’t be examined by routine methods, Nano-materials exist menace to human health and environment. It is necessary to study the health activities.The dissertation chose three kinds of materials, they were nano-TiO₂ , MWNT, nano-Fe. The dissertation mainly researched on the lung injury. All rats were intratracheally instilled with 10mg/kg bw or 1mg/kg bw of nano-materials. The control group was intratracheally instilled the same volume physiological brine. All rats were intratracheally instilled every three days. At the tenth day, all rats were sacrificed and their lungs were lavaged. The following indexes in bronchoalveolar lavage fluid were examined, （1） amount of leukocyte, （2） activities of LDH, （3） contents of HYP. Lung/body coefficient was measured. At last, did morphological observation and compared change ratio of body weight.Through the experiment we come to the conclusion as follows:1. Body weight increase ratio of nano-TiO₂ -10mg/kg bw group was the lowest. All indexes of nano-10mg/kg bw group were obviously higher than the control group and the nano-1mg/kg bw group （P<0.01 or P<0.05）. At the same dose, three indexesof nano-10mg/kg bw group were higher than normal-10mg/kg bw group（P<0.01或P<0.05）. The amount of leukocyte was also higher than normal-10mg/kg bw group, but the difference was not statistical significance. The results of morphological observation indicated that the rats in nano-10mg/kg bw group had the heavest injury of lungs.2. The body weight increase ratio of MWNT-10mg/kg bw group was the lowest. Other indexes of MWNT-10mg/kg bw group were obviously higher than the control group and the group of MWNT-1mg/kg bw（P<0.01 or P<0.05）. The results of morphological observation indicated that the rats in MWNT 10mg/kg bw group had the heavest injury of lungs.3. The body weight increase ratio of nanosized iron 10mg/kg bw group was lowest. Lung/body coefficient, Leukocyte count and Hydroxyproline（HYP） concentration of nanosized iron 10mg/kg bw group were higher than the control group and the group of nanosized iron 1mg/kg bw（P<0.01 or P<0.05）.4. The activitiy of LDH of nano-TiO₂ -10mg/kg bw group was the highest. The content of HYP of MWNT-10mg/kg bw group was the highest. Both groups did injury of lungs, but the injury degree was different.Analyzing the results, gained conclusions as follows:1. Under the same experimental condition, the effect of lung injury was more severity in high-dose nano-TiO₂ than normal TiO₂ and low-dose nano-TiO₂ .2. Under this experimental condition, MWNT had injured lungs. All indexes of high-dose MWNT were higher than low-dose MWNT. MWNT was evaluated to existing latent menace to human health and environment.3. Under this experimental condition, the effect of lung injury is more severity in nano-iron. All indexes of high-dose nano-iron were higher than low-dose nano-iron. Nano-iron existed latent menace to human health and environment.4. At the same dose, three kinds of materials existed notable differences in body weight increase ratio, the activities of LDH and the contents of HYP. It indicated that there were some differences in lung toxicity and action mechanism between different nano-materials.更多还原