FOLH1 and metastatic prostate carcinoma: A urea-based ligand (ACUPA)with free carboxylic acid groups interacts with the S1′ pocketof PSMA selectively and has been employed in several single-photonemission computed tomography (SPECT) and positron emission tomography(PET) imaging and theranostic agents for prostate cancer.3−6177Lu-based PSMA-targeted radiotherapy is currently utilizedin the clinic to treat metastatic prostate cancer.7−9 Inspired bypromising clinical studies, there has been increased interest in utilizingPSMA targeting for nanoparticle delivery for imaging and therapy.10−17