The prostate specific membrane antigen (PSMA), extensively overexpressed on prostate cancer (PCa) cell surface, has been validated as a diagnostic biomarker for PCa. However, insufficient attention has been paid to the development of PSMA-specific probes loaded with small chemical molecules for the in vivo molecular imaging of PCa. In this study, we innovatively labelled superparamagnetic iron oxide nanoparticles with a PSMA-targeting Glu-Urea-Lys scaffold. An optimized synthetic route was developed to offer a physiochemically stable probe. The probe demonstrated high binding affinity (0.38 ± 0.08 μg(Fe)/mL) and binding specificity to PSMA expressed on prostate cancer cell surface in vitro. In a xenograft PCa mouse model, significant negative contrast of the implanted prostate cancer xenograft could be specifically observed by MRI 6 h after tail vein injection of the tracer (Fe, 20 mg/kg), exhibiting its potential to exclusively enhance magnetic resonance detection of PCa.
