The FASEB JournalResearch Communication 19 F magnetic resonance imaging for stem/progenitor cell tracking with multiple unique perfluorocarbon nanobeacons

MRI has been employed to elucidate the migratory behavior of stem/progenitor cells noninva- sively in vivo with traditional proton ( 1 H) imaging of iron oxide nanoparticle-labeled cells. Alternatively, we demon- strate that fluorine ( 19 F) MRI of cells labeled with differ- ent types of liquid perfluorocarbon (PFC) nanoparticles produces unique and sensitive cell markers distinct from any tissue background signal. To define the utility for cell tracking, mononuclear cells harvested from human umbilical cord blood were grown under proendothelial conditions and labeled with nanoparticles composed of two distinct PFC cores (perfluorooctylbromide and perfluoro-15-crown-5 ether). The sensitivity for detect- ing and imaging labeled cells was defined on 11.7T (research) and 1.5T (clinical) scanners. Stem/progeni- tor cells (CD34CD133CD31) readily internalized PFC nanoparticles without aid of adjunctive labeling techniques, and cells remained functional in vivo. PFC- labeled cells exhibited distinct 19 F signals and were readily detected after both local and intravenous injec- tion. PFC nanoparticles provide an unequivocal and unique signature for stem/progenitor cells, enable spatial cell localization with 19 F MRI, and permit quan- tification and detection of multiple fluorine signatures via 19 F MR spectroscopy. This method should facilitate