Abstract: Provided are a fibroblast activation protein inhibitor (FAPI) dimer compound, an FAPI dimer-based positron emission tomography (PET) imaging agent for tumor diagnosis, and a preparation method and use thereof. An amphiphilic polyethylene glycol (PEG) chain and a dimerized structure of FAPI in the FAPI dimer compound with a structure shown in formula I can improve the in vivo kinetic properties of the compound and prolong a residence time of the compound in a tumor, thereby improving the uptake and imaging effects in the tumor. The accurate tumor diagnosis can be achieved by labeling the FAPI dimer compound with a diagnostic nuclide (68Ga), which has promising application prospects in PET imaging for diagnosis and in the preparation of a therapeutic nuclide (such as 177Lu or 90Y)-labeled drug for treating a FAP-?-expressing tumor.

Abstract: The present disclosure relates to the technical field of medicine, and in particular to a fibroblast activation protein inhibitor (FAPI) dimer compound, an FAPI dimer-based positron emission tomography (PET) imaging agent for tumor diagnosis, and a preparation method and use thereof An amphiphilic polyethylene glycol (PEG) chain and a dimerized structure of FAPI in the FAPI dimer compound with a structure shown in formula I provided by the present disclosure can improve the in vivo kinetic properties of the compound and prolong a residence time of the compound in a tumor, thereby improving the uptake and imaging effects in the tumor. The accurate tumor diagnosis can be achieved by labeling the FAPI dimer compound with a diagnostic nuclide (68Ga), which has promising application prospects in PET imaging for diagnosis and in the preparation of a therapeutic nuclide (such as 177Lu or 90Y)-labeled drug for treating a FAP-?-expressing tumor.