Intrinsically radioactive [64Cu]CuInS/ZnS quantum dots for PET and optical imaging: improved radiochemical stability and controllable Cerenkov luminescence.

Abstract

Functionalized quantum dots (QDs) have been widely explored for multimodality bioimaging and proven to be versatile agents. Attaching positron-emitting radioisotopes onto QDs not only endows their positron emission tomography (PET) functionality, but also results in self-illuminating QDs, with no need for an external light source, by Cerenkov resonance energy transfer (CRET). Traditional chelation methods have been used to incorporate the radionuclide, but these methods are compromised by the potential for loss of radionuclide due to cleavage of the linker between particle and chelator, decomplexation of the metal, and possible altered pharmacokinetics of nanomaterials. Herein, we described a straightforward synthesis of intrinsically radioactive [(64)Cu]CuInS/ZnS QDs by directly incorporating (64)Cu into CuInS/ZnS nanostructure with (64)CuCl2 as synthesis precursor. The [(64)Cu]CuInS/ZnS QDs demonstrated excellent radiochemical stability with less than 3% free (64)Cu detected even after exposure to serum containing EDTA (5 mM) for 24 h. PEGylation can be achieved in situ during synthesis, and the PEGylated radioactive QDs showed high tumor uptake (10.8% ID/g) in a U87MG mouse xenograft model. CRET efficiency was studied as a function of concentration and (64)Cu radioactivity concentration. These [(64)Cu]CuInS/ZnS QDs were successfully applied as an efficient PET/self-illuminating luminescence in vivo imaging agents.

• Authors: Weisheng Guo, Xiaolian Sun, Orit Jacobson, Xuefeng Yan, Kyunghyun Min, Avinash Srivatsan, Gang Niu, Dale O Kiesewetter, Jin Chang, Xiaoyuan Chen
• Journal: ACS nano (ACS Nano) Vol. 9 Issue 1 Pg. 488-95 (Jan 27 2015) ISSN: 1936-086X [Electronic] United States
• PMID: 25549258 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Copper Radioisotopes
• Radiopharmaceuticals
• Sulfides
• Zinc Compounds
• Indium
• Copper
• zinc sulfide

Topics

• Animals
• Cell Line, Tumor
• Cell Transformation, Neoplastic
• Copper (chemistry)
• Copper Radioisotopes
• Drug Stability
• Glioblastoma (diagnostic imaging, pathology)
• Humans
• Indium (chemistry)
• Luminescence
• Mice
• Optical Imaging (methods)
• Positron-Emission Tomography (methods)
• Quantum Dots (chemistry)
• Radiochemistry
• Radiopharmaceuticals (chemistry, pharmacokinetics)
• Sulfides (chemistry)
• Tissue Distribution
• Zinc Compounds (chemistry)