title: 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.affiliation: School of Materials Science and Engineering, School of Life Sciences, Tianjin University , Tianjin 300072, China.
authors.forename: Weisheng
authors.initials: W
authors.lastname: Guo
authors.forename: Xiaolian
authors.initials: X
authors.lastname: Sun
authors.forename: Orit
authors.initials: O
authors.lastname: Jacobson
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Yan
authors.forename: Kyunghyun
authors.initials: K
authors.lastname: Min
authors.forename: Avinash
authors.initials: A
authors.lastname: Srivatsan
authors.forename: Gang
authors.initials: G
authors.lastname: Niu
authors.forename: Dale O
authors.initials: DO
authors.lastname: Kiesewetter
authors.forename: Jin
authors.initials: J
authors.lastname: Chang
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Chen
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic; D003300:Copper / Q000737:chemistry*; D003301:Copper Radioisotopes; D004355:Drug Stability; D005909:Glioblastoma / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007204:Indium / Q000737:chemistry*; D049449:Luminescence; D051379:Mice; D061848:Optical Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D045663:Quantum Dots / Q000737:chemistry*; D011854:Radiochemistry; D019275:Radiopharmaceuticals / Q000737:chemistry* / Q000493:pharmacokinetics; D013440:Sulfides / Q000737:chemistry*; D014018:Tissue Distribution; D017967:Zinc Compounds / Q000737:chemistry*
chemical_list: D003301:Copper Radioisotopes; D019275:Radiopharmaceuticals; D013440:Sulfides; D017967:Zinc Compounds; D007204:Indium; D003300:Copper; C031238:zinc sulfide
keywords: CRET; CuInS/ZnS; PET imaging; dual-modality imaging; quantum dots