A very popular RGD cyclic peptide. c(RGDfK) is a 5-amino acid head-tailamide ring tumor-targeting peptide that specifically targets tumor microvessels and cancer cells by binding to αvβ3 integrin on the cell surface.
There is a series of integrin isoforms that recognize and bind to the tripeptide sequence RGD (arginine-glycine-aspartate), representing the most prominent recognition motifs involved in cell adhesion. Among them, cyclo (-RGDfK) has been widely used in biomaterial coatings to improve cell adhesion or as a imaging agent for tumor treatment.