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
文摘
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 Feb>3b>Ob>4b>@NaYFb>4b> core/shell nanoparticles (NPs) with different cation dopants in the shell or core, including Cob>0.16b>Feb>2.84b>Ob>4b>@NaYFb>4b>(Yb, Er) and Feb>3b>Ob>4b>@NaYFb>4b>(Yb, Tm). These NPs are stabilized by bisphosphonate polyethylene glycol conjugates (BP-PEG), and then show a high transverse relaxivity (rb>2b>) up to 326 mM–1 s–1 at 3T, a high affinity to [18F]-fluoride or radiometal-bisphosphonate conjugates (e.g., 64Cu and 99mTc), 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 Cob>0.16b>Feb>2.84b>Ob>4b>@NaYFb>4b>(Yb, Er)-BP-PEG (10K) NPs cleared from the blood pool more slowly than positively charged NPs Feb>3b>Ob>4b>@NaYFb>4b>(Yb, Tm)-BP-PEG (2K). Preliminary results in sentinel lymph node imaging in mice indicate the advantages of multimodal imaging.