Fluorinated Polymer Nanoparticles as a Novel 19F MRI Contrast Agent Prepared by DendrimerInitiated Living Radical Polymerization

Novel fluorinated polymer nanoparticles PNPs for 19F MRI were prepared by living radical polymerization initiated by a dendrimer. The dendritic macroinitiator with Br substituents was synthesized from hydroxygroupterminated G2 polyamidoamine dendrimers. The arborescent fluorinated polymers of 2,2,3,3tetrafluoropropyl methacrylate and 2,2,2trifluoroethyl methacrylate were characterized in molecular weight, the number of arms, the degree of polymerization per arm, and the diameter as a whole. The PNP diameter was precisely controlled by the molecular weight in the range of 3–25 nm. In addition, the fluorinated PNP gave a narrow resonance by 19F NMR spectroscopy. These results indicate that the fluorinated PNP can be used as a new type of 19F MRI agent.