Investigation of PET/MRI Dual-modal Lymph Imaging Probe Based on ⁶⁴Cu and Superparamagnetic Iron Oxide Nanoparticle

The dextran-coated superparamagnetic iron oxide nanoparticles were synthesized by the method of chemical co-precipitation firstly, then dithiocarbamate bisphosphonate (DTCBP) was labeled with ⁶⁴Cu effectively, and ⁶⁴Cu(DTCBP)₂ was obtained. By the binding properties of DTCBP to the iron oxide, a PET/MRI dual-modal lymph imaging probe of ⁶⁴Cu(DTCBP)₂-IO-Dex was prepared by mixing IO-Dex and the pre-labeling ⁶⁴Cu(DTCBP)₂. The radiochemical purity of ⁶⁴Cu(DTCBP)₂-IO-Dex is higher than 99% after purification. The biodistribution of ⁶⁴Cu(DTCBP)₂-IO-Dex in Balb/C mice shows that the uptakes of popliteal lymph node and iliac lymph node are 2.31%ID and 1.84%ID at 1 h after injection, respectively. At the same time, the uptake of the liver is 15.41%ID/g. The radioactivity is no uptake in spleen until 3 h after injection. The uptake of radioactivity in popliteal lymph node can be clearly observed in the mode of PET/CT or MRI.