Automated Radiolabeling and Evaluation of [18F]FPMBBG: A Novel Cardiac Neuronal PET Imaging Agent

• DOI: 10.1002/jlcr.4139
• Publication Date: 2025-03-04T17:30:06Z
• Authors: Min Ju; Wanjie Ren; Zongyao Zhang; Jie Lu; Kai Han; Lei Wang; Wei Fang

ABSTRACTThis study reports the automated radiosynthesis and evaluation of [18F]FPMBBG, a radiopharmaceutical designed to target the norepinephrine transporter (NET). A newly developed fully protected benzylguanidine precursor, which prevents interference from non‐protected benzylguanidine part during the nucleophilic process, has enabled a one‐pot two‐step fully automated cassette‐based synthesis of [18F]FPMBBG. This advancement enhances the feasibility of the synthesis, ensures reproducibility, and allows for the production of substantial quantities of the radiotracer, paving the way for future clinical applications. [18F]FPMBBG was prepared in radiochemical yield of ~ 23% (n = 6, decay‐corrected) within 70 min, with a radiochemical purity exceeding 98%, and molar activity of > 2 GBq/μmol. In studies using miniature Bama pigs, [18F]FPMBBG showed favorable distribution, providing high‐contrast cardiac images at an early stage. Moreover, desipramine inhibition studies confirmed the high NET specificity of [18F]FPMBBG. The efficient automated synthesis, robust heart uptake, and minimal background signal highlight [18F]FPMBBG as a promising PET tracer for assessing cardiac sympathetic neuronal function.