Background: Silicon nanoparticles are widely used in daily life. Therefore, they attract increased attention because of their potential biotoxicity to the lungs when inhaled. The aims of this study are to explore the organism distribution and genotoxicity of silica nanoparticles in human bronchial epithelial cells (BEAS-2B).
Methods: The biodistribution of silica with different particle sizes in human bronchial epithelial cells was observed by transmission electron microscopy (TEM). DNA damage was detected by single-cell gel electrophoresis (comet assay).
Results: TEM revealed that SiO₂ nanoparticles with different sizes can be uptaken by cells and be localized in the cytoplasm and the nucleus. Compared with micro-silica, nano-silica in BEAS-2B cells can inflict more severe DNA damage (P<0.05).
Conclusions: The particle size of silica nanoparticles can be used to determine their distribution in biological cells. Compared with micro-silica, nano-silica has higher genotoxicity.
背景与目的: 纳米二氧化硅广泛应用于社会生产生活中，肺部是吸入暴露纳米二氧化硅的主要靶器官，因此，二氧化硅对肺部的生物毒性作用引起人们的广泛关注。本研究旨在探讨纳米二氧化硅在人支气管上皮细胞内的亚细胞分布和遗传毒性。
方法: 应用透射电子显微镜（transmission electron microscope, TEM）观察不同粒径二氧化硅在人支气管上皮细胞（immortalized human bronchial epithelium cells, BEAS-2B）内的亚细胞分布；应用单细胞凝胶电泳检测不同粒径二氧化硅处理BEAS-2B细胞24 h后的DNA损伤，了解不同粒径二氧化硅的遗传毒性作用。
结果: 透射电镜观察到微米二氧化硅不能进入细胞，纳米二氧化硅赋存在细胞质，纳米二氧化硅导致线粒体、内质网等细胞器损伤。纳米二氧化硅导致比微米二氧化硅更严重的DNA损伤（P < 0.05）。
结论: 二氧化硅的粒径决定二氧化硅颗粒物是否能进入细胞及在细胞内的分布，纳米二氧化硅对细胞遗传毒性比微米二氧化硅严重。