indocyanine green + pH (low) insertion peptide

**Indocyanine green + pH (low) insertion peptide** is a combination molecular imaging agent consisting of the clinically approved near-infrared fluorescent dye indocyanine green (ICG) covalently linked to a pH (low) insertion peptide (pHLIP). The peptide selectively inserts into cell membranes in acidic microenvironments, a feature typical of many tumor cells due to their glycolytic activity. Upon systemic administration (commonly intravenous), the agent accumulates in tumors by targeting the acidic extracellular surface, enabling high-contrast, prolonged visualization of blood vessels and tumor tissues during surgery. The fluorescence signal of ICG is greatly enhanced (up to 20-fold) when tethered to the cell membrane via pHLIP. pHLIP ICG is being developed primarily for fluorescence-guided surgery and tumor delineation, and is currently undergoing clinical trials as a tumor-targeting intraoperative imaging agent.

Brand names

pHLIP ICG

Other names

pH-low insertion peptide-indocyanine greenindocyanine green + pHLIP