Preparation of a Multiple-Targeting NIR-Based Fluorogenic Probe and Its Application for Selective Cancer Cell Imaging.

To improve cancer selectivity of imaging agents, we synthesized the triple-targeting, near-infrared (NIR) based fluorogenic probe, Oct-FK(PBA)-NIR. The new probe consists of (1) octreotide as a synthetic ligand of somatostatin receptors, (2) a H2O2-responsive phenylboronic acid, (3) a dipeptide substrate for cathepsin B, and (4) a NIR fluorophore. The results of cell studies show that the probe can be used for selective imaging of cancer cells in the NIR range without interference with normal cells.