Sentinel lymph node imaging and biopsy is important to clinical assessment of cancer metastasis, and novel non-radioactive lymphographic tracers have been actively pursued over the years. Here, we develop gold molecular clusters (Au₂₅) functionalized by phosphorylcholine (PC) ligands for NIR-II (1000–3000 nm) fluorescence imaging of draining lymph nodes in 4T1 murine breast cancer and CT26 colon cancer tumor mouse models. The Au-phosphorylcholine (Au-PC) probes exhibit ‘super-stealth’ behavior with little interactions with serum proteins, cells and tissues in vivo, which differs from the indocyanine green (ICG) dye. Subcutaneous injection of Au-PC allows lymph node mapping by NIR-II fluorescence imaging at an optimal time of ~ 0.5 − 1 hour postinjection followed by rapid renal clearance. Preclinical NIR-II fluorescence LN imaging with Au-PC affords high signal to background ratios and high safety and biocompatibility, promising for future clinical translation.

前哨淋巴结成像和活检对于癌症转移的临床评估很重要，多年来一直在积极探索新型非放射性淋巴结示踪剂。在这里，我们开发了金分子簇 (Au ₂₅) 由磷酸胆碱 (PC) 配体功能化，用于 4T1 小鼠乳腺癌和 CT26 结肠癌肿瘤小鼠模型中引流淋巴结的 NIR-II (1000–3000 nm) 荧光成像。Au-磷酸胆碱 (Au-PC) 探针表现出“超级隐身”行为，与体内血清蛋白、细胞和组织几乎没有相互作用，这与吲哚菁绿 (ICG) 染料不同。皮下注射 Au-PC 允许在注射后约 0.5 - 1 小时的最佳时间通过 NIR-II 荧光成像进行淋巴结映射，然后进行快速肾脏清除。使用 Au-PC 的临床前 NIR-II 荧光 LN 成像可提供高信号背景比以及高安全性和生物相容性，有望用于未来的临床转化。