School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Med-X Research Institute and School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
J Hazard Mater. 2024 Mar 5;465:133371. doi: 10.1016/j.jhazmat.2023.133371. Epub 2023 Dec 26.
The emerging stress caused by nanomaterials in the environment is of great concern because they can have toxic effects on organisms. However, thorough study of the interactions between cells and diverse nanoparticles (NPs) using a unified approach is challenging. Here, we present a novel approach combining stimulated emission depletion (STED) microscopy and scanning transmission electron microscopy (STEM) for quantitative assessment, real-time tracking, and in situ imaging of the intracellular behavior of gold-silver nanoclusters (AuAgNCs), based on their fluorescence and electron properties. The results revealed an aggregated state of AuAgNCs within the mitochondria and an increase in sulfur content in AuAgNCs, presumably owing to their reaction with thiol-containing molecules inside the mitochondria. Moreover, AuAgNCs (100 μg/mL) induced a 75% decline in mitochondrial membrane potential and a 12-fold increase of mitochondrial reactive oxygen species in comparison to control. This mitochondrial damage may be triggered by the reaction of AuAgNCs with thiol, which provides direct imaging evidence for uncovering the action mechanism of AuAgNCs on the mitochondria. The proposed dual-imaging strategy using STED and STEM is a potential tool to offer valuable insights into cytotoxicity between subcellular structures and diverse NPs, and can serve as a key strategy for nanomaterial biosafety assessment.
环境中新兴的纳米材料所带来的压力引起了人们的极大关注，因为它们可能对生物体产生毒性作用。然而，使用统一的方法来深入研究细胞与各种纳米颗粒（NPs）之间的相互作用具有挑战性。在这里，我们提出了一种新的方法，结合受激发射损耗（STED）显微镜和扫描透射电子显微镜（STEM），基于其荧光和电子特性，对金-银纳米团簇（AuAgNCs）的细胞内行为进行定量评估、实时跟踪和原位成像。结果表明 AuAgNCs 在线粒体中呈聚集状态，并且 AuAgNCs 中的硫含量增加，这可能是由于它们与线粒体内部含硫分子的反应。此外，与对照组相比，AuAgNCs（100μg/mL）使线粒体膜电位降低了 75%，线粒体活性氧增加了 12 倍。这种线粒体损伤可能是由 AuAgNCs 与硫的反应引发的，这为揭示 AuAgNCs 对线粒体作用机制提供了直接的成像证据。该研究提出的使用 STED 和 STEM 的双成像策略可能是一种潜在的工具，可以深入了解亚细胞结构与各种 NPs 之间的细胞毒性，并可以作为纳米材料生物安全性评估的关键策略。
