In Vivo Positron Emission Tomography (PET) Imaging with an αvβ6 Specific Peptide Radiolabeled using 18F-“Click” Chemistry: Evaluation and Comparison with the Corresponding 4-[18F]Fluorobenzoyl- and 2-[18F]Fluoropropionyl-Peptides

Abstract

Numerous radiolabeled peptides have been utilized for in vivo imaging of a variety of cell surface receptors. For applications in PET using [¹⁸F]fluorine, peptides are radiolabeled via a prosthetic group approach. We previously developed solution-phase ¹⁸F-“click” radiolabeling and solid-phase radiolabeling using 4-[¹⁸F]fluorobenzoic and 2-[¹⁸F]fluoropropionic acids. Here we compare the three different radiolabeling approaches and report the effects on PET imaging and pharmacokinetics. The prosthetic groups did have an effect; metabolites with significantly different polarities were observed.