Lymphatic system plays a vital role in facilitating tumor metastasis in the early stage. It is urgent to understand the structure, development and function of the lymphatics via the high-resolution and real-time imaging during the period. In this study, by using different ratios of polymer dots (Pdots) as nanoprobe, multi-scale multi-modal imaging methods are employed to observe the structure and function of the lymphatics in the tumor-bearing mice. Our findings demonstrate that the lymphatics display enlargement and thickening before the tumor metastasis. Moreover, the distortions, burrs, new-born branches and dysfunctional valves are observed. Furthermore, the combination of multiphoton confocal microscope and uDICSO realizes the complete transparency and super-resolution imaging of lymph nodes and lymphatic vessels together for the first time. These results show the exciting possibility of using functional Pdots for imaging the lymphatics in tumor metastasis, development and disease models in small animals.

淋巴系统在促进肿瘤早期转移中起着至关重要的作用。迫切需要在此期间通过高分辨率和实时成像来了解淋巴管的结构，发育和功能。在这项研究中，通过使用不同比例的聚合物点（Pdots）作为纳米探针，采用多尺度多模态成像方法观察荷瘤小鼠淋巴管的结构和功能。我们的发现表明，淋巴管在肿瘤转移之前显示出增大和增厚。此外，观察到变形，毛刺，新生分支和瓣膜功能异常。此外，多光子共聚焦显微镜和uDICSO的结合首次实现了淋巴结和淋巴管的完全透明性和超分辨率成像。