Microplastics (MP) and nanoplastics (NP) pollutions pose a rising environmental threat to humans and other living species, given their escalating presence in essential resources that living subjects ingest and/or inhale. Herein, to elucidate the potential health implications of MP/NP, we report for the first time by using label-free hyperspectral stimulated Raman scattering (SRS) imaging technique developed to quantitatively monitor the bioaccumulation and metabolic toxicity of MP/NP within live zebrafish larvae during their early developmental stages. Zebrafish embryos are exposed to environmentally related concentrations (3–60 μg/ml) of polystyrene (PS) beads with two typical sizes (2 μm and 50 nm). Zebrafish are administered isotope-tagged fatty acids through microinjection and dietary intake for in vivo tracking of lipid metabolism dynamics. In vivo 3D quantitative vibrational imaging of PS beads and intrinsic biomolecules across key zebrafish organs reveals that gut and liver are the primary target organs of MP/NP, while only 50 nm PS beads readily aggregate and adhere to the brain and blood vessels. The 50 nm PS beads are also found to induce more pronounced hepatic inflammatory response compared to 2 μm counterparts, characterized by increased biogenesis of lipid droplets and upregulation of arachidonic acid detected in zebrafish liver. Furthermore, Raman-tagged SRS imaging of fatty acids uncovers that MP/NP exposure significantly reduces yolk lipid utilization and promotes dietary lipid storage in zebrafish, possibly associated with developmental delays and more pronounced food dilution effects in zebrafish larvae exposed to 2 μm PS beads. The hyperspectral SRS imaging in this work shows that MP/NP exposure perturbs the development and lipid metabolism in zebrafish larvae, furthering the understanding of MP/NP ingestions and consequent toxicity in different organs in living species.

中文翻译：

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使用高光谱受激拉曼散射显微镜定量评估和监测活体斑马鱼中微塑料和纳米塑料的分布和脂质代谢


微塑料 (MP) 和纳米塑料 (NP) 污染对人类和其他生物物种造成的环境威胁日益严重，因为它们在生物体摄入和/或吸入的基本资源中的存在不断增加。在此，为了阐明 MP/NP 的潜在健康影响，我们首次报告使用无标记高光谱受激拉曼散射 (SRS) 成像技术来定量监测活体斑马鱼幼虫内 MP/NP 的生物累积和代谢毒性在他们的早期发展阶段。将斑马鱼胚胎暴露于环境相关浓度（3–60 μg/ml）的聚苯乙烯 (PS) 珠中，该珠具有两种典型尺寸（2 μm 和 50 nm）。通过显微注射和饮食摄入，向斑马鱼施用同位素标记的脂肪酸，以体内跟踪脂质代谢动态。 PS 珠子和斑马鱼关键器官的内在生物分子的体内 3D 定量振动成像表明，肠道和肝脏是 MP/NP 的主要靶器官，而只有 50 nm PS 珠子容易聚集并粘附在大脑和血管上。与 2 μm 对应物相比，50 nm PS 珠还被发现能诱导更明显的肝脏炎症反应，其特征是斑马鱼肝脏中检测到的脂滴生物发生增加和花生四烯酸上调。此外，拉曼标记的脂肪酸 SRS 成像发现，MP/NP 暴露显着降低了斑马鱼卵黄脂质利用率并促进了膳食脂质储存，这可能与暴露于 2 μm PS 珠的斑马鱼幼虫的发育延迟和更明显的食物稀释效应有关。 这项工作中的高光谱 SRS 成像表明，MP/NP 暴露会扰乱斑马鱼幼虫的发育和脂质代谢，从而进一步了解 MP/NP 摄入以及生物物种不同器官中随之而来的毒性。