Near-infrared targeted EGFR fluorescent probe for tumor imaging and diagnosis

The incidence of prostate cancer has increased rapidly in recent years. And the detection of tumor markers is an effective way for early diagnosis and poor prognosis. Prostate cancer is associated with growth factor receptors. Epidermal growth factor receptor (EGFR) expression is increased in a majority of prostate cancer patients. Peptide probes have the advantages of convenient modification and selective and rapid clearance in the molecular imaging of tumors. H1 is a short peptide designed and modified based on the CDR3 region of a nanobody targeting the epidermal growth factor receptor (EGFR) with high affinity for malignant tumors that overexpress EGFR. The CDR3 sequence of nanobodies has a long finger-like structure that allows deep interaction with the cryptic epitope of the antigen. Here we synthesized a sensitive fluorescent peptide probe of H1 conjugated to imaging moieties MPA. Experimental data showed that H1-MPA targets EGFR with high affinity. Meanwhile, H1-MPA has high tumor uptake and a strong signal-to-noise ratio. In addition, the near-infrared fluorescent probe H1-MPA can determine tumor boundaries and can be used to monitor and prevent tumor metastasis, including hepatic metastasis, for accurate tumor diagnosis. H1-MPA provides a promising tool for cancer diagnosis.