Synthesis, Characterization, and Application of Core Shell Co0.16Fe2.84O4@NaYF4(Yb, Er) and Fe3O4@NaYF4(Yb, Tm) Nanoparticle as Trimodal (MRI, PET/SPECT, and Optical) Imaging Agents
Multimodal nanoparticulate materials are described, offering magnetic, radionuclide, and fluorescent imaging capabilities to exploit the complementary advantages of magnetic resonance imaging (MRI) positron emission tomography/single photon emission commuted tomography (PET/SPECT) and optical imaging. They comprise Fe3O4@NaYF4 core/shell nanoparticles (NPs) with different cation dopants in the shell or core, including Co0.16Fe2.84O4@NaYF4(Yb, Er) and Fe3O4@NaYF4(Yb, Tm) These NPs are stabilized by bisphosphonate polyethylene glycol conjugates (BP PEG) and then show a high transverse relaxivity (r2) up to 326 mM( 1) s( 1) at 3T, a high affinity to (18)F] fluoride or radiometal bisphosphonate conjugates (e.g. (64)Cu and (99m)Tc) and fluorescent emissions from 500 to 800 nm under excitation at 980 nm. The biodistribution of intravenously administered particles determined by PET/MR imaging suggests that negatively charged Co0.16Fe2.84O4@NaYF4(Yb, Er) BP PEG (10K) NPs cleared from the blood pool more slowly than positively charged NPs Fe3O4@NaYF4(Yb, Tm) BP PEG (2K) Preliminary results in sentinel lymph node imaging in mice indicate the advantages of multimodal imaging.
Bioconjugate chemistry