TiO2纳米颗粒对小鼠脑毒性的实验研究

目的了解注入到小鼠气管内的TiO2纳米颗粒对脑部的毒性。方法将粒径3 nm的TiO2纳米颗粒分别按0.4、4.0、40.0 mg/kg的剂量注入到3组小鼠的气管内,每组13只小鼠。3 d后用电感耦合等离子体质谱仪(ICP-MS)测定每组中3只小鼠的大脑和血液中TiO2的含量变化,同时测定每组中5只小鼠大脑匀浆液中H2O2的浓度变化,每组中的其他5只小鼠的大脑用于制备常规病理切片进行光学显微镜观察。结果小鼠的大脑和血液中TiO2含量随TiO2纳米颗粒注入剂量的增加而增加。小鼠大脑匀浆中H2O2的浓度也随TiO2纳米颗粒注入剂量的增加而增加;小鼠大脑病理学观察表明,TiO2纳米颗粒对大脑造成的损伤主要表现为血脑屏障的破坏、组织内溢血和组织坏死。结论注入到气管内的TiO2纳米颗粒会对小鼠大脑造成剂量依赖性损伤。

Experimental Study on Brain Toxicity Induced by TiO2 Nanoparticles in Mice

Objective To study the brain toxicity induced by TiO2 nanoparticles intratracheally instilled into the mice lungs.Methods TiO2 nanoparticles of 3 nm diameter were intratracheally instilled into three groups of mice lungs with respective dosages of 0.4,4.0 and 40.0 mg/kg and with 13 mice in each group.Three days after the intratracheal instillation,the inductively coupled plasma mass spectrometry(ICP-MS)was used to detect the TiO2 contents in cerebrum and blood of 3 mice in each group.In addition,5 mice in each group were chosen for measuring H2O2 concentrations in brain homogenate,and another 5 mice in each group were used to prepare the routine cerebrum pathological slices for observation under light microscopy.Results The TiO2 contents in the cerebrum and blood,and the H2O2 concentrations in the brain homogenate increased as dosages of TiO2 nanoparticles increased.The pathological observation demonstrated that the cerebral lesions induced by TiO2 nanoparticles were characterized by destruction of blood-brain barrier,tissue hemorrhage and necrosis.Conclusions The TiO2 nanoparticles intratracheally instilled into the mice lungs could induce dose-dependent cerebral toxicity.