Description:

The investigators designed and synthesized a novel fibroblast activation protein (FAP) ligand (DOTA-GPFAPI-04) by assembling three functional moieties: a quinoline-based FAP inhibitor for specifically targeting FAP, a FAP substrate Gly-Pro as a linker for increasing the FAP protein interaction, and a 2,2',2",2‴-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid (DOTA) chelator for radiolabeling with different radionuclides. Molecular docking studies investigated the FAP targeting ability of DOTA-GPFAPI-04. DOTA-GPFAPI-04 was then radiolabeled with 68Ga to give 68Ga-DOTA-GPFAPI-04 for positron emission tomography (PET) imaging. The investigators found that the 68Ga-DOTA-GPFAPI-04 has high stability, targeted specificity, and longer retention time. The tumor-to-muscle (T/M) ratio for 68Ga-DOTA-GPFAPI-04 reached 9.15.