PET Imaging and Biodistribution of Silicon Quantum Dots in Mice

Investigation of nanomaterial disposition and fate in the body is critical before such material can be translated into clinical application. Herein a new macrocyclic ligand (64)Cu(2+) complex was synthesized and used to label dextran-coated silicon quantum dots (QD), with an average hydrodynamic diameter of 15.1 +/- 7.6 nm. The chelate showed exceptional stability demonstrated by no loss radiolabel under a ligand competion reaction with EDTA. The QDs biodistribution in mice was quantitatively evaluted by in vivo positron mission tomography (PET) imaging and ex vivo gamma counting. Results showed that they were excreted via renal filtratin shortly postinjection and also accumulated in the liver.