A NIR-II fluorescent probe for high contrast non-invasive imaging of tumors with a high EGFR-expression

Abstract

NIR-II fluorescence imaging is one powerful tool of molecular imaging, which shows a promising future in cancer early diagnosis and image-guided therapy. The advancements of molecular imaging probes would be conducive to the enhancement in the contrast and fidelity of cancer imaging. Epidermal growth factor receptor (EGFR) is a biomarker widely used for cancer theranostics, and we herein developed a novel EGFR-targeting NIR-II fluorescent probe CH1055-PEG1k-GE11 utilizing CH1055 as a core to couple with EGFR-targeting peptides GE11 via a mild crosslinking strategy. The results suggested that CH1055-PEG1k-GE11 possessed enhanced EGFR-targeting capability in vitro and achieved high contrast imaging of EGFR-highly expressing tumors in vivo. During the 24 h imaging after intravenous injection, CH1055-PEG1k-GE11 enabled a tumor-to-background ratio substantially surpassing the Rose criterion of 5 since 1 h postinjection (p.i.) and reached the highest value of 12.89 at 2 h p.i. Moreover, this probe was partially renal-clearable and exhibited favorable biocompatibility based on the results of cell viability and hematoxylin and eosin assays. Based on the above facts, CH1055-PEG1k-GE11 may have promising application prospects in the imaging of tumors with a high EGFR-expression.