Abstract The emerging second near-infrared (NIR-II) fluorescence imaging has shown great promise for in vivo imaging of small animals such as mice, yet the onward movement to large-size animals such as rats is still undeveloped. In this work, for the first time, we report comprehensive NIR-II deciphering of brain blood vasculature and main organs of living rats based on aggregation-induced emission (AIE) dots. The AIE dots possess simultaneously high brightness, excellent stability with various treatments, and good biocompatibility. Thanks to the long emission range and high brightness, in vivo NIR-II fluorescence microscopic imaging with the AIE dots beyond 1200 nm allows for visualizing rat brain vasculature with high spatial resolution (∼4 μm) and deep penetration (700 μm), representing the highest penetration depth and best resolution of rat brain imaging yet achieved in the field. The NIR-II AIE dots also enable the detection of tiny vascular blockage in real time at the early stage of cerebral thrombosis. Furthermore, in vivo non-invasive monitoring of rat’s gastrointestinal tract and bladder in a high-contrast manner helps to better understand the digestive system and excretory processes. This work will inspire new insights into the development of advanced NIR-II technique for large animal imaging, rendering great promise for real applications.

中文翻译：

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用于 NIR-II 解密活老鼠的高度稳定和明亮的 AIE 点

摘要 新兴的第二近红外 (NIR-II) 荧光成像技术在小鼠等小动物体内成像方面显示出了巨大的前景，但对大鼠等大型动物的进一步运动尚待开发。在这项工作中，我们首次报告了基于聚集诱导发射 (AIE) 点对活体大鼠的脑血管系统和主要器官的全面 NIR-II 破译。AIE点同时具有高亮度、各种处理的优异稳定性和良好的生物相容性。由于长发射范围和高亮度，AIE 点超过 1200 nm 的体内 NIR-II 荧光显微成像允许以高空间分辨率（~4 μm）和深度穿透（700 μm）可视化大鼠脑血管系统，代表了该领域迄今为止实现的大鼠脑成像的最高穿透深度和最佳分辨率。NIR-II AIE 点还可以在脑血栓形成的早期实时检测微小的血管阻塞。此外，以高对比度方式对大鼠胃肠道和膀胱进行体内无创监测有助于更好地了解消化系统和排泄过程。这项工作将激发对大型动物成像的先进 NIR-II 技术开发的新见解，为实际应用带来巨大希望。以高对比度的方式对大鼠胃肠道和膀胱进行体内无创监测，有助于更好地了解消化系统和排泄过程。这项工作将激发对大型动物成像的先进 NIR-II 技术开发的新见解，为实际应用带来巨大希望。以高对比度的方式对大鼠胃肠道和膀胱进行体内无创监测，有助于更好地了解消化系统和排泄过程。这项工作将激发对大型动物成像的先进 NIR-II 技术开发的新见解，为实际应用带来巨大希望。