Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic.
Center for Evidence - based Health Care, Taipei Medical University - Shuang Ho Hospital, No. 291, Zhongzheng Road, Zhonghe District, New Taipei City 23561, Taiwan.
IET Nanobiotechnol. 2018 Sep;12(6):695-700. doi: 10.1049/iet-nbt.2017.0109.
Titanium dioxide (TiO) has been vastly used commercially, especially as white pigment in paints, colorants, plastics, coatings, cosmetics. Certain industrial uses TiO in diameter <100 nm. There are three common exposure routes for TiO: (i) inhalation exposure, (ii) exposure via gastrointestinal tract, (iii) dermal exposure. Inhalation and gastrointestinal exposure appear to be the most probable ways of exposure, although nanoparticle (NP) penetration is limited. However, the penetration rate may increase substantially when the tissue is impaired. When TiO NPs migrate into the circulatory system, they can be distributed into all tissues including brain. In brain, TiO lead to oxidative stress mediated by the microglia phagocytic cells which respond to TiO NPs by the production and release of superoxide radicals that convert to multiple reactive oxygen species (ROS). The ROS production may also cause the damage of blood-brain barrier which then becomes more permeable for NPs. Moreover, several studies have showed neuron degradation and the impairment of spatial recognition memory and learning abilities in laboratory rodent exposed to TiO NPs.
二氧化钛（TiO）在商业上被广泛应用，特别是作为白色颜料用于油漆、着色剂、塑料、涂料、化妆品。某些工业用途中 TiO 的粒径<100nm。TiO 的三种常见暴露途径为：（i）吸入暴露，（ii）经胃肠道暴露，（iii）皮肤暴露。吸入和胃肠道暴露似乎是最有可能的暴露途径，尽管纳米颗粒（NP）的穿透受到限制。然而，当组织受损时，穿透率可能会大大增加。当 TiO NPs 迁移到循环系统中时，它们可以分布到包括大脑在内的所有组织中。在大脑中，TiO 通过吞噬细胞（即小胶质细胞）介导的氧化应激，对 TiO NPs 产生和释放超氧自由基，进而转化为多种活性氧物质（ROS）作出反应。ROS 的产生也可能导致血脑屏障的损伤，使 NPs 更容易穿透。此外，一些研究表明，在实验室啮齿动物中，暴露于 TiO NPs 会导致神经元退化以及空间识别记忆和学习能力受损。
