A near-infrared fluorescent probe with assembly/aggregation-induced retention effect for specific diagnosis of metastasis and image-guided surgery in breast cancer.

Image-guided surgery is crucial for achieving complete tumor resection, reducing postoperative recurrence and improving patient survival. However, current clinical near-infrared fluorescent probes, such as indocyanine green (ICG), face two main limitations: 1) lack of active tumor targeting, and 2) short retention time in tumors, which restricts real-time imaging during surgery. To address these issues, we developed a near-infrared fluorescent probe capable of in situ nanofiber formation within tumor lesions. This probe actively targets the integrin αβ receptors overexpressed on breast cancer cells and exhibits assembly/aggregation-induced retention effects at the tumor site, significantly extending the imaging time window. Additionally, we found that the probe's fluorescence intensity can be enhanced under receptor induction. Due to its excellent tumor specificity and sensitivity, 1FCG-FFGRGD not only identifies primary breast cancer but also precisely locates smaller lymph node metastases and detects sub-millimeter peritoneal metastases. In summary, this near-infrared probe, leveraging assembly/aggregation-induced retention effects, holds substantial potential for various biomedical applications.