Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China.
Environ Int. 2022 Apr;162:107177. doi: 10.1016/j.envint.2022.107177. Epub 2022 Mar 15.
Nanoplastics are more likely to be suspended in air and pose a risk of respiratory exposure. However, the early health effects of low-dose nanoplastics on the respiratory system, which are expected to reflect the risk of atmospheric nanoplastics, need to be further evaluated. In this study, nanoparticles of polyethylene terephthalate, a representative plastic polymer in air, were prepared by a precipitation method. The toxicity impacts of nano-PET at environmental concentrations on the human lung carcinoma cell A549 cells were evaluated. Although the nano-PET was identified to enter the cells by confocal microscope observation and alkali-assisted thermal depolymerization coupled with LC-MS/MS analysis, the nano-PET exhibited low toxicity on mitochondrial membrane potential levels and cell apoptosis. At low concentrations of 0.10 and 0.98 μg/mL, the nano-PET had a slight promotion effect on cell viability, while an inhibitory effect on cell viability presented at higher nano-PET concentrations of 98.40 and 196.79 μg/mL. The cell survival rate at 98.4 and 196.79 μg/mL of nano-PET are lower than that of the control, and significant oxidative stress in cells caused by the nano-PET exposure at 49.2 μg/mL was observed. A decrease tendency of mitochondrial membrane potential with the increasing nano-PET exposure presents, which is consistent with the change of reactive oxygen species. Furthermore, nano-PET at ≦ 98.4 μg/mL could not increase the sum of apoptotic in the cells, but the late apoptotic cells increased with the increase of the exposure dose. The major mechanism of the toxic effect of nano-PET on cells may be the increase of reactive oxygen species caused by oxidative stress, which in turn induces a decrease in the mitochondrial membrane potential. This study provides information on the toxicity of nano-PET at environmental concentrations in human lung cells, which helps to enrich the risk cognition of nanoplastics in the respiratory system.
纳米塑料更容易悬浮在空气中，存在呼吸暴露的风险。然而，大气纳米塑料预计会反映出低剂量纳米塑料对呼吸系统的早期健康影响，需要进一步评估。在这项研究中，通过沉淀法制备了空气中代表性塑料聚合物聚对苯二甲酸乙二醇酯的纳米颗粒。评估了环境浓度下的纳米 PET 对人肺癌细胞 A549 细胞的毒性影响。尽管通过共聚焦显微镜观察和碱辅助热解聚结合 LC-MS/MS 分析确定纳米 PET 进入细胞，但纳米 PET 对线粒体膜电位水平和细胞凋亡的毒性较低。在 0.10 和 0.98μg/mL 的低浓度下，纳米 PET 对细胞活力有轻微的促进作用，而在更高浓度的 98.40 和 196.79μg/mL 时则表现出抑制作用。纳米 PET 在 98.4 和 196.79μg/mL 时的细胞存活率低于对照组，并且在 49.2μg/mL 时观察到纳米 PET 暴露引起的细胞明显氧化应激。随着纳米 PET 暴露的增加，线粒体膜电位呈下降趋势，与活性氧的变化一致。此外，纳米 PET 在 ≦ 98.4μg/mL 时不会增加细胞中凋亡的总和，但随着暴露剂量的增加，晚期凋亡细胞增加。纳米 PET 对细胞的毒性作用的主要机制可能是氧化应激引起的活性氧增加，进而导致线粒体膜电位降低。这项研究提供了环境浓度下纳米 PET 对人肺细胞毒性的信息，有助于丰富呼吸系统中纳米塑料的风险认知。
