手术切除是结直肠癌（CRC）患者的有效治疗方法，但隐匿性转移阻碍了疗效。目前，尚无有效方法实现肿瘤阳性淋巴结（LN）的术中诊断。在此，我们采用近红外-II（NIR-II）有机供体-π-受体-π-供体探针FE-2PEG，该探针在1100 nm以上具有明亮的荧光，具有优异的光稳定性、血液循环时间和生物相容性，以实现具有改进的时间和空间分辨率的高性能生物成像。重要的是，FE-2PEG 通过增强的渗透性和保留效应，在原位 CRC、转移性肠系膜淋巴结和腹膜转移瘤中显示出有效的被动富集。 NIR-II荧光引导手术（FGS）下腹膜微转移切除的敏感性为94.51%，特异性为86.59%，阳性预测值（PPV）为96.57%，阴性预测值为79.78%。即使对于小于 3 毫米的微转移，PPV 仍然达到 96.07%。病理染色和NIR-II显微成像证明FE-2PEG能够成功勾画肿瘤和正常组织之间的边界。采用 FE-2PEG (1100 ~ 1300 nm) 和 PbS@CdS 量子点 (> 1500 nm) 的双色 NIR-II 成像策略成功地在手术过程中保护了血液供应和正常组织。基于 NIR-II 的 FGS 为 CRC 的精确术中诊断和微创手术提供了广阔的前景。© 2023。作者。

Surgical resection is an effective treatment for colorectal cancer (CRC) patients, whereas occult metastases hinder the curative effect. Currently, there is no effective method to achieve intraoperatively diagnosis of tumor-positive lymph nodes (LNs). Herein, we adopt a near-infrared-II (NIR-II) organic donor-pi-acceptor-pi-donor probe FE-2PEG, which exhibits bright fluorescence over 1100 nm, excellent photostability, blood circulation time, and biocompatibility, to achieve high-performance bioimaging with improved temporal and spatial resolution. Importantly, the FE-2PEG shows efficient passive enrichment in orthotopic CRC, metastatic mesenteric LNs, and peritoneal metastases by enhanced permeability and retention effect. Under NIR-II fluorescence-guided surgery (FGS), the peritoneal micrometastases were resected with a sensitivity of 94.51%, specificity of 86.59%, positive predictive value (PPV) of 96.57%, and negative predictive value of 79.78%. The PPV still achieves 96.07% even for micrometastases less than 3 mm. Pathological staining and NIR-II microscopy imaging proved that FE-2PEG could successfully delineate the boundary between the tumor and normal tissues. Dual-color NIR-II imaging strategy with FE-2PEG (1100 ~ 1300 nm) and PbS@CdS quantum dots (> 1500 nm) successfully protects both blood supply and normal tissues during surgery. The NIR-II-based FGS provides a promising prospect for precise intraoperative diagnosis and minimally invasive surgery of CRC.© 2023. The Author(s).