title: 64Cu Core-labeled nanoparticles with high specific activity via metal-free click chemistry.
abstract: A novel strategy based on metal-free "click" chemistry was developed for the copper-64 radiolabeling of the core in shell-cross-linked nanoparticles (SCK-NPs). Compared with Cu(I)-catalyzed click chemistry, this metal-free strategy provides the following advantages for Cu-64 labeling of the core of SCK-NPs: (1) elimination of copper exchange between nonradioactive Cu in the catalyst and DOTA-chelated Cu-64; (2) elimination of the internal click reactions between the azide and acetylene groups in the same NPs; and (3) increased efficiency of the click reaction because water-soluble Cu(I) does not need to reach the hydrophobic core of the NPs. When 50 mCi Cu-64 was used for the radiolabeling, the specific activity of the radiolabeled product was 975 Ci/μmol at the end of synthesis, which represents the attachment of ca. 500 Cu-64 atoms per SCK-NP, giving in essence a 500-fold amplification of specific activity of the NP over that of the Cu-64 chelate. To the best of our knowledge, this is the highest specific activity obtained for Cu-64-labeled nanoparticles.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
authors.forename: Dexing
authors.initials: D
authors.lastname: Zeng
authors.forename: Nam S
authors.initials: NS
authors.lastname: Lee
authors.forename: Yongjian
authors.initials: Y
authors.lastname: Liu
authors.forename: Dong
authors.initials: D
authors.lastname: Zhou
authors.forename: Carmen S
authors.initials: CS
authors.lastname: Dence
authors.forename: Karen L
authors.initials: KL
authors.lastname: Wooley
authors.forename: John A
authors.initials: JA
authors.lastname: Katzenellenbogen
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Welch
mesh_terms: D003300:Copper / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D008968:Molecular Conformation; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D003300:Copper