Radiochemistry and Preclinical PET Imaging of (68)Ga-Desferrioxamine Radiotracers Targeting Prostate-Specific Membrane Antigen.

Radiochemistry and Preclinical PET Imaging of (68)Ga-Desferrioxamine Radiotracers Targeting Prostate-Specific Membrane Antigen. Mol Imaging. 2017 Jan-Dec;16:1536012117737010 Authors: Gourni E, Del Pozzo L, Bartholomä M, Kiefer Y, T Meyer P, Maecke HR, Holland JP Abstract Radiotracers incorporating the urea-based Glu-NH-C(O)-NH-Lys group have gained prominence due to their role in targeting prostate-specific membrane antigen (PSMA)-a clinical biomarker of prostate cancer. Here, the synthesis, radiolabeling, and in vitro and in vivo characterization of two (68)Ga-radiolabeled Glu-NH-C(O)-NH-Lys radiotracers conjugated to the desferrioxamine B (DFO) chelate were evaluated. Two linker groups based on amide bond and thiourea coupling chemistries were employed to develop (68)Ga-DFO-Nsucc-PSMA ((68)Ga-4) and (68)Ga-DFO- pNCS-Bn-PSMA ((68)Ga-7), respectively. Radiosynthesis proceeded quantitatively at room temperature with high radiochemical yields, chemical/radiochemical purities, and specific activities. Pharmacokinetic profiles of (68)Ga-4 and (68)Ga-7 were assessed using positron-emission tomography (PET) in mice bearing subcutaneous LNCaP tumors. Data were compared to the current clinical benchmark radiotracer (68)Ga-HBED-CC-PSMA ((68)Ga-1) (HBED = N,N'-Bis(2-hydroxy-5-(ethylene-beta-carboxy)benzyl)ethylenediamine N,N'-diacetic acid). Results indicated that the target binding affinity, protein association, blood pool and background org...
Source: Molecular Imaging - Category: Radiology Tags: Mol Imaging Source Type: research