The biological fate of nanoparticles (NPs) taken up by organisms from their environment is a crucial issue for assessing ecological hazard. Despite its importance, it has scarcely been addressed due to the technical difficulties of doing so in whole organism in vivo studies. Here, by using transmission electron microscopy and energy dispersive X-ray spectroscopy (TEM-EDS), we describe the key aspects that characterize the interaction between an aquatic organism of global ecological and economic importance, the early larval stage of the Japanese oyster (Crassostrea gigas), and model gold NPs dispersed in their environment. The small size of the model organism allowed for a high-throughput visualization of the subcellular distribution of NPs, providing a comprehensive and robust picture of the route of uptake, mechanism of cellular permeation, and the pathways of clearance counterbalancing bioaccumulation. We show that NPs are ingested by larvae and penetrate cells through alimentary pinocytic/phagocytic mechanisms. They undergo intracellular digestion and storage inside residual bodies, before excretion with feces or translocation to phagocytic coelomocytes of the visceral cavity for potential extrusion or further translocation. Our mechanistically-supported findings highlight the potential of oyster larvae and other organisms which feature intracellular digestion processes to be exposed to man-made NPs and thus any risks associated with their inherent toxicity.

中文翻译：

---

牡蛎幼虫摄取的金纳米颗粒被细胞通过消化内吞途径内化。

生物从其环境中吸收的纳米颗粒（NPs）的生物命运是评估生态危害的关键问题。尽管它很重要，但由于在整个生物体内研究中这样做的技术困难，因此几乎没有得到解决。在这里，通过使用透射电子显微镜和能量色散X射线光谱（TEM-EDS），我们描述了表征具有全球生态和经济意义的水生生物，日本牡蛎幼体早期阶段（Crassostrea）之间相互作用的关键方面。 gigas），并模拟分散在其环境中的金纳米颗粒。模型有机体尺寸小，可实现NPs亚细胞分布的高通量可视化，从而提供了摄取途径，细胞渗透机制，以及清除平衡生物积累的途径。我们表明，NPs被幼虫摄入，并通过消化性红细胞/吞噬机制渗透细胞。它们会在粪便中排泄或转移至内脏吞噬性粒细胞，然后进行潜在的挤压或进一步转移，然后在残留体内进行细胞内消化和储存。我们的机制支持的研究结果突出了牡蛎幼虫和其他具有细胞内消化过程的生物体暴露于人造NP的潜力，因此可能存在与其固有毒性相关的任何风险。它们会在粪便中排泄或转移至内脏吞噬性粒细胞，然后进行潜在的挤压或进一步转移，然后在残留体内进行细胞内消化和储存。我们的机制支持的研究结果突出了牡蛎幼虫和其他具有细胞内消化过程的生物体暴露于人造NP的潜力，因此可能存在与其固有毒性相关的任何风险。它们会在粪便中排泄或转移至内脏吞噬性粒细胞，然后进行潜在的挤压或进一步转移，然后在残留体内进行细胞内消化和储存。我们的机制支持的研究结果突出了牡蛎幼虫和其他具有细胞内消化过程的生物体暴露于人造NP的潜力，因此可能存在与其固有毒性相关的任何风险。