Perfluorocarbon-Based ¹⁹ F MRI Nanoprobes for In Vivo Multicolor Imaging

In vivo multicolor imaging is important for monitoring multiple biomolecular or cellular processes in biology. ¹⁹ F magnetic resonance imaging (MRI) is an emerging in vivo imaging technique because it can non-invasively visualize ¹⁹ F nuclei without endogenous background signals. Therefore, ¹⁹ F MRI probes capable of multicolor imaging are in high demand. Herein, we report five types of perfluorocarbon-encapsulated silica nanoparticles that show ¹⁹ F NMR peaks with different chemical shifts. Three of the nanoprobes, which show spectrally distinct ¹⁹ F NMR peaks with sufficient sensitivity, were selected for in vivo multicolor ¹⁹ F MRI. The nanoprobes exhibited ¹⁹ F MRI signals with three colors in a living mouse. Our in vivo multicolor system could be utilized for evaluating the effect of surface functional groups on the hepatic uptake in a mouse. This novel multicolor imaging technology will be a practical tool for elucidating in vivo biomolecular networks by ¹⁹ F MRI.