EphA2-targeted NIR-I/II fluorescent probe for specific imaging of colorectal cancer.

Complete surgical resection is the cornerstone of therapy for early-stage colorectal cancer. However, accurate intraoperative tumor localization remains a clinical challenge. Targeted fluorescent probes have emerged as effective tools to assist real-time tumor visualization during surgery. EPH-3-DBS is an EphA2-targeted NIR-I/NIR-II fluorescent molecular probe, composed of the novel cyanine-based dye DBS and the high-affinity EphA2-targeting peptide EPH-3. EPH-3-DBS exhibits excellent optical properties and high binding specificity for EphA2-expressing tumors. In vivo imaging demonstrated that EPH-3-DBS selectively accumulates in tumor tissues, whereas the non-targeted DBS shows no significant tumor affinity. Superior imaging performance was observed in both orthotopic colorectal cancer and liver metastasis models. Owing to its high tumor-to-background ratio (TBR>2.0) and prolonged imaging window, EPH-3-DBS holds significant potential for application in fluorescence-guided surgery.