In the recent decades, fluorogens with aggregation-induced emission (AIEgens) have been intensively explored in biomedical applications. One main strategy to bring these hydrophobic AIEgens into the aqueous biological environment is to encapsulate them in nanoparticles with functionalized polymeric matrices. However, exploration of reliable strategies that can afford AIE nanoparticles with uniform size and stable loading efficiency with minimized variation still remains a challenge. Here, we rationally designed amphiphilic AIEgens, constructed by a hydrophobic donor-acceptor-donor (D-A-D) core and hydrophilic polyethylene glycol (PEG) chain. The afforded amphiphilic AIEgens can self-assemble into uniform nanoparticles with average sizes of ~35 nm, showing an emission maximum beyond 1000 nm and quantum yields (QYs) above 10%. We then used the bright AIE nanoparticles for multiscale intravital vascular fluorescence imaging in the second near-infrared window (NIR-II, 1000–1700 nm) in mouse and rabbit models with a high-resolution of ~38 μm and a penetration depth of ~1 cm. As such, our results demonstrate an efficient self-assembly strategy to construct advanced AIE nanoparticles for angiography.

在最近的几十年中，在生物医学应用中已深入研究了具有聚集诱导发射的氟气（AIEgens）。将这些疏水性AIEgens引入水性生物环境的一种主要策略是将它们封装在具有功能化聚合物基质的纳米颗粒中。然而，探索能够提供具有均匀尺寸和稳定负载效率且变化最小的AIE纳米颗粒的可靠策略仍然是一个挑战。在这里，我们合理设计了两亲性AIEgens，由疏水性供体-受体-供体（DAD）核心和亲水性聚乙二醇（PEG）链构成。所提供的两亲性AIEgen可以自组装成平均粒径约为35 nm的均匀纳米颗粒，显示出超过1000 nm的最大发射峰和超过10％的量子产率（QYs）。然后，我们在小鼠和兔模型的第二个近红外窗口（NIR-II，1000-1700 nm）中将明亮的AIE纳米粒子用于多尺度活体血管荧光成像，其高分辨率为〜38μm，穿透深度为〜 1厘米 因此，我们的结果证明了一种有效的自组装策略，可构建用于血管造影的先进AIE纳米颗粒。