Imaging and quantification of nanoparticles in single cells in their most natural condition are expected to facilitate the biotechnological applications of nanoparticles and allow for better assessment of their biosafety risks. However, current imaging modalities either require tedious sample preparation or only apply to nanoparticles with specific physicochemical characteristics. Here, the emerging hyperspectral stimulated Raman scattering (SRS) microscopy, as a label‐free and nondestructive imaging method, is used for the first time to investigate the subcellular distribution of nanoparticles in the protozoan Tetrahymena thermophila. The two frequently studied nanoparticles, polyacrylate‐coated α‐Fe₂O₃ and TiO₂, are found to have different subcellular distribution pattern as a result of their dissimilar uptake routes. Significant uptake competition between these two types of nanoparticles is further discovered, which should be paid attention to in future bioapplications of nanoparticles. Overall, this study illustrates the great promise of hyperspectral SRS as an analytical imaging tool in nanobiotechnology and nanotoxicology.

中文翻译：

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高光谱受激拉曼散射在单细胞中对纳米粒子吸收竞争的无标记成像

预计在最自然条件下对单个细胞中的纳米颗粒进行成像和定量分析将有助于纳米颗粒的生物技术应用并允许对其生物安全风险进行更好的评估。但是，当前的成像方式要么需要繁琐的样品制备，要么仅适用于具有特定理化特性的纳米粒子。在这里，新兴的高光谱刺激拉曼散射（SRS）显微镜作为一种无标记和非破坏性的成像方法，首次用于研究原生动物四膜虫嗜热菌中纳米颗粒的亚细胞分布。两个频繁研究的纳米颗粒，聚丙烯酸酯-涂覆的α-Fe ₂ ö ₃和TiO ₂由于它们不同的摄取途径，发现它们具有不同的亚细胞分布模式。进一步发现了这两种类型的纳米颗粒之间的显着吸收竞争，在未来的纳米颗粒生物应用中应引起注意。总的来说，这项研究说明了高光谱SRS作为纳米生物技术和纳米毒理学中的分析成像工具的巨大前景。