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Updated: Jul 20, 2025

Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
Radiofluorination of an Anionic, Azide-Functionalized Teroligomer by Copper-Catalyzed Azide-Alkyne Cycloaddition
Barbara Wenzel1, Maximilian Schmid2,3, Rodrigo Teodoro1
1Department of Neuroradiopharmaceuticals, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf, 04318 Leipzig, Germany.
Abstract:
This study describes the synthesis, radiofluorination and purification of an anionic amphiphilic teroligomer developed as a stabilizer for siRNA-loaded calcium phosphate nanoparticles (CaP-NPs). As the stabilizing amphiphile accumulates on nanoparticle surfaces, the fluorine-18-labeled polymer should enable to track the distribution of the CaP-NPs in brain tumors by positron emission tomography after application by convection-enhanced delivery. At first, an unmodified teroligomer was synthesized with a number average molecular weight of 4550 ± 20 Da by free radical polymerization of a defined composition of methoxy-PEG-monomethacrylate, tetradecyl acrylate and maleic anhydride. Subsequent derivatization of anhydrides with azido-TEG-amine provided an azido-functionalized polymer precursor (o14PEGMA-N) for radiofluorination. The 18F-labeling was accomplished through the copper-catalyzed cycloaddition of o14PEGMA-N with diethylene glycol-alkyne-substituted heteroaromatic prosthetic group [ which was synthesized with a radiochemical yield (RCY) of about 38% within 60 min using a radiosynthesis module. The 18F-labeled polymer [ was obtained after a short reaction time of 2-3 min by using CuSO4/sodium ascorbate at 90 °C. Purification was performed by solid-phase extraction on an anion-exchange cartridge followed by size-exclusion chromatography to obtain [ with a high radiochemical purity and an RCY of about 15%.
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