Abstract：
Nanoplastic is recognized as an emerging environmental pollutant due to the anticipated ubiquitous distribution, increasing concentration in the ocean, and potential adverse health effects. While our understanding of the ecological impacts of nanoplastics is still limited, we benefit from relatively rich toxicological studies on other nanoparticles such as nano metal oxides. However, the similarity and difference in the toxicokinetic and toxicodynamic aspects of plastic and metallic nanoparticles remain largely unknown. In this study, juvenile Pacific white shrimp Litopenaeus vannamei was exposed to two types of nanoparticles at environmentally relative low and high concentrations, i.e., 100 nm polystyrene nanoplastics (nano-PS) and titanium dioxide nanoparticles (nano-TiO2) via dietary exposure for 28 days. The systematic toxicological evaluation aimed to quantitatively compare the accumulation, excretion, and toxic effects of nano-PS and nano-TiO2. Our results demonstrated that both nanoparticles were ingested by L. vannamei with lower egestion of nano-TiO2 than nano-PS. Both nanoparticles inhibited the growth of shrimps, damaged tissue structures of the intestine and hepatopancreas, disrupted expression of immune-related genes, and induced intestinal microbiota dysbiosis. Nano-PS exposure caused proliferative cells in the intestinal tissue, and the disturbance to the intestinal microbes was also more serious than that of nano-TiO2. The results indicated that the effect of nano-PS on the intestinal tissue of L. vannamei was more severe than that of nano-TiO2 with the same particle size. The study provides new theoretical basis of the similarity and differences of their toxicity, and highlights the current lack of knowledge on various aspects of absorption, distribution, metabolism, and excretion (ADME) pathways of nanoplastics.
摘要：
由于预期的无处不在的分布，纳米塑料被认为是一种新兴的环境污染物。增加海洋中的浓度，和潜在的不良健康影响。虽然我们对纳米塑料的生态影响的理解仍然有限，我们受益于对其他纳米颗粒如纳米金属氧化物的相对丰富的毒理学研究。然而,塑料和金属纳米颗粒在毒物动力学和毒物动力学方面的相似性和差异仍然很大程度上未知。在这项研究中,太平洋小白虾凡纳滨对虾暴露于环境相对低和高浓度的两种类型的纳米粒子，即，100nm聚苯乙烯纳米塑料（纳米PS）和二氧化钛纳米颗粒（纳米TiO2）通过饮食暴露28天。系统的毒理学评价旨在定量比较积累，排泄,纳米PS和纳米TiO2的毒性作用。我们的结果表明，两种纳米颗粒均被南美白对虾摄入，纳米TiO2的摄入量低于纳米PS。两种纳米粒子都抑制了虾的生长，肠和肝胰腺的组织结构受损，免疫相关基因的表达中断，并诱导肠道微生物群失调。Nano-PS暴露导致肠组织中的细胞增殖,对肠道微生物的干扰也比纳米TiO2严重。结果表明，纳米PS对凡纳滨对虾肠道组织的影响比相同粒径的纳米TiO2更为严重。该研究为其毒性的相似性和差异性提供了新的理论依据,并强调目前对吸收的各个方面缺乏了解，分布，新陈代谢，和纳米塑料的排泄(ADME)途径。
