Group of Mutagenesis, Department of Genetics and Microbiology, Faculty of Biosciences, Universitat Autònoma de Barcelona, Campus of Bellaterra, 08193 Cerdanyola del Vallès, Barcelona, Spain; Zoology Department, Faculty of Sciences, Sohag University, 82524 Sohag, Egypt.
Group of Mutagenesis, Department of Genetics and Microbiology, Faculty of Biosciences, Universitat Autònoma de Barcelona, Campus of Bellaterra, 08193 Cerdanyola del Vallès, Barcelona, Spain; Zoology Department, Faculty of Sciences, Sohag University, 82524 Sohag, Egypt.
Sci Total Environ. 2022 Oct 10;842:156923. doi: 10.1016/j.scitotenv.2022.156923. Epub 2022 Jun 23.
Since heavy metals and micro-/nanoplastics (MNPLs) can share common environmental niches, their potential interactions could modulate their hazard impacts. The current study was planned to evaluate the potential interactions between silver compounds (silver nanoparticles or silver nitrate) and two different sizes of polystyrene nanoplastics (PSNPLs) (PS-50 and PS-500 nm), administered via ingestion to Drosophila larvae. While egg-to-adult survival was not affected by the exposure to silver compounds, PSNPLs, or their coexposures, the combined treatments succeeded to restore the delay of fly emergence induced by silver compounds. Transmission electron microscopy (TEM) and inductively coupled plasma mass spectrometry (ICP-MS) showed the ability of PSNPLs to transport silver compounds (regardless of their form) across the intestinal barrier, delivering them into the hemolymph of Drosophila larvae in a concentration exceeding that mediated by the exposure to silver compounds alone. The molecular response (gene expression) of Drosophila larvae greatly fluctuated, accordingly if exposures were administered alone or in combination. Although PSNPLs produced some oxidative stress in the hemocytes of Drosophila, especially at the highest dose (1 mM), higher levels were observed after silver exposure, regardless of its form. Interestingly, the oxidative stress of silver, especially that produced by nano‑silver, drastically decreased when coexposed with PSNPLs. Similar effects were observed regarding the DNA damage induced in Drosophila hemocytes, where cotreatment decreased the genotoxicity induced by silver compounds. This antagonistic interaction could be attributed to the ability of tiny plastic specks to confine silver, avoiding its bioavailability, and diminishing their potential impacts.
由于重金属和微/纳米塑料（MNPLs）可以共享共同的环境小生境，它们之间的潜在相互作用可能会调节它们的危害影响。本研究旨在评估银化合物（银纳米粒子或硝酸银）和两种不同尺寸的聚苯乙烯纳米塑料（PSNPLs）（PS-50 和 PS-500nm）之间的潜在相互作用，这些塑料通过摄食被递送至果蝇幼虫体内。虽然暴露于银化合物、PSNPLs 或它们的共同暴露不会影响卵到成虫的存活率，但联合处理成功地恢复了银化合物诱导的果蝇出现延迟。透射电子显微镜（TEM）和电感耦合等离子体质谱（ICP-MS）显示 PSNPLs 能够将银化合物（无论其形式如何）穿过肠屏障运输，将其递送至果蝇幼虫的血淋巴中，其浓度超过单独暴露于银化合物所介导的浓度。果蝇幼虫的分子反应（基因表达）也随之大幅波动，这取决于暴露是单独进行还是联合进行。尽管 PSNPLs 在果蝇的血细胞中产生了一些氧化应激，尤其是在最高剂量（1mM）下，但在银暴露后观察到更高的水平，无论其形式如何。有趣的是，银的氧化应激，尤其是纳米银产生的氧化应激，在与 PSNPLs 共同暴露时大大降低。在果蝇血细胞中诱导的 DNA 损伤也观察到类似的效应，其中共同处理降低了银化合物诱导的遗传毒性。这种拮抗相互作用可以归因于微小塑料斑点将银限制在其中的能力，从而避免其生物利用度，并降低其潜在影响。
