To date, the occurrence, fate and toxicity of metal-based NPs in the environment is under investigated. Their unique physicochemical, biological and optical properties, responsible for their advantageous application, make them intrinsically different from their bulk counterpart, raising the issue of their potential toxic specificity or “nanosize effect”. The aim of this study was to investigate copper bioaccumulation, subcellular distribution and toxic effect in the marine benthic species Scrobicularia plana exposed to two forms of sediment-associated copper, as nanoparticles (CuO NPs) and as soluble ions (CuCl₂). Results showed that the exposure to different copper forms activated specific organism's metal handling strategies. Clams bioaccumulated soluble copper at higher concentrations than those exposed to sediment spiked with CuO NPs. Moreover, CuO NPs exposure elicited a stronger detoxification response mediated by a prompt mobilization of CuO NPs to metal-containing granules as well as a delayed induction of MT-like proteins, which conversely, sequestered soluble copper since the beginning of the exposure at levels significantly different from the control. Eventually, exposure to high concentrations of either copper form led to the same acute toxic effect (100% mortality) but the outcome was delayed in bivalves exposed to CuO NPs suggesting that the mechanisms underlying toxicity were copper form-specific. Indeed, while most of soluble copper was associated to the mitochondrial fraction suggesting an impairment of the ATP synthesis capacity at mitochondrial level, CuO NPs toxicity was most likely caused by the oxidative stress mediated by their bioaccumulation in the enzymatic and mitochondrial metabolically available fractions.

迄今为止，正在研究环境中基于金属的NP的发生，命运和毒性。它们独特的物理化学，生物学和光学性质决定了它们的优势应用，使其与大批同类产品本质上不同，从而引发了潜在的毒性特异性或“纳米级效应”的问题。这项研究的目的是研究暴露于两种形式的沉积物相关铜的海洋底栖生物平面藻类中铜的生物富集，亚细胞分布和毒性作用，即纳米颗粒（CuO NPs）和可溶离子（CuCl ₂）。结果表明，暴露于不同的铜形式激活了特定生物的金属处理策略。蛤的生物累积可溶性铜的浓度高于暴露于掺有CuO NP的沉积物的铜。此外，CuO NPs的暴露引起了更强的解毒反应，这是由于CuO NPs迅速动员到含金属的颗粒以及MT类蛋白的延迟诱导所致，相反，由于暴露开始以来，螯合可溶性铜的水平显着与控件不同。最终，暴露于高浓度的任何一种铜形式都导致相同的急性毒性作用（100％死亡率），但是暴露于CuO NP的双壳类动物的结果被延迟，表明毒性的潜在机制是特定于铜形式的。确实，