Synthesis and Evaluation of 99mTc-Labeled l-Aspartic Acid as a EuK Polymer Linker for Targeting PSMA to a Novel SPECT Tumor Tracer

The development of novel tracers targeting prostate-specific membrane antigen (PSMA) has great potential for improving the diagnosis and treatment of prostate cancer (PCa). This study aimed to improve the absolute tumor uptake and tumor-to-background ratios (TBRs) of this novel PSMA tracer by increasing the number of pharmacophores, Glu-urea-Lys (EuK), that specifically bind to PSMA. We successfully synthesized four radioligands and prepared a total of 12 stable radiotracers by coordinating