Analysis of Biodistribution and in vivo Toxicity of Varying Sized Polystyrene Micro and Nanoplastics in Mice

Bohai Du,1 Tianlan Li,1 Haoqi He,1 Xun Xu,2 Chunmei Zhang,1 Xianzhu Lu,1 Yuhan Wang,1 Jingyi Cao,1 Yinghan Lu,1 Yiwa Liu,1 Shanshan Hu,1 Juxiao Li,1 Li Li,1 Ming Shi1 1Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, Guangdong Province, 523808, People’s Republic of China; 2Experimental Animal Center, Guangdong Medical University, Dongguan, Guangdong Province, 523808, People’s Republic of ChinaCorrespondence: Li Li; Ming Shi, School of Public Health, Guangdong Medical University, Dongguan, Guangdong Province, 523808, People’s Republic of China, Tel +86-15889530426 ; +86-769-22896568, Email lily2017@gdmu.edu.cn; shiming@gdmu.edu.cnIntroduction: Studies have shown that microplastics (MPs) and nanoplastics (NPs) could accumulate in the human body and pose a potential threat to human health. The purpose of this study is to evaluate the biodistribution and toxicity of MPs/NPs with different particle sizes comprehensively and thoroughly.Methods: The purpose of this study was to investigate the biodistribution and in vivo toxicity of polystyrene (PS) MPs/NPs with different sizes (50 nm, 100 nm, and 500 nm). The BALB/c mice were given 100 μL of PS50, PS100 and PS500 at the dosage of 1 mg/kg BW or 10 mg/kg BW, respectively, by gavage once a day. After 28 consecutive days of treatment, the biodistribution of differently sized PS MPs/NPs was determined through cryosection fluorescence microscopy and fluorescent microplate reader analysis, and the subsequent effects of differently sized PS MPs/NPs on histopathology, hematology and blood biochemistry were also evaluated.Results: The results showed that the three different sizes of PS MPs/NPs were distributed in the organs of mice, mainly in the liver, spleen, and intestine. At the same time, the smaller the particle size, the more they accumulate in the body and more easily penetrate the tissue. During the whole observation period, no abnormal behavior and