Abstract
The synthesis, solution stability and 64Cu2+ labeling of magnetite nanoparticles (NPs) coated with different macrocycles is reported, together with the stability of the resulting radioisotope-labeled NPs to transchelation by the competing ligand cyclam, and their stability in blood serum. Three macrocycles, 1,4-bis(2-pyridylmethyl)-1,4,7-triazacyclononane (dmptacn), 1,4,8,11-tetraazacyclotetradecane (cyclam) and 1,4,7,10-tetraazacyclododecane (cyclen), and 3-aminopropyltriethoxysilane were used to modify the magnetite NPs. The ligands were covalently linked to the surface of the NPs with high efficiency by reaction of the corresponding 3-(3-(triethoxysiloxy)propoxy)propan-2-ol derivatives with the NPs. According to transmission electron microscopy (TEM), the uncoated magnetite NPs and macrocycle-functionalized congeners have an average diameter of 6 to 7 nm. The NPs form stable colloidal suspensions in 0.05 M aqueous 2-(N-morpholino)ethanesulfonic acid (MES) buffer, which consist of larger aggregates with a mean hydrodynamic size of about 200 nm. The NPs with the appended macrocycles can be efficiently labeled with 64Cu2+ ions and the radioactivity persists in rat plasma for at least 24 h. Challenge experiments with cyclam also indicate that the radiocopper complexes are highly stable, with the dmptacn-functionalized NPs showing the highest resistance to metal ion leakage. Overall, the dmptacn-functionalized iron oxide NPs provide an excellent platform for the development of robust multimodal cancer imaging/therapeutic agents.
Original language | English |
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Pages (from-to) | 2705 - 2712 |
Number of pages | 8 |
Journal | New Journal of Chemistry |
Volume | 35 |
Issue number | 11 |
DOIs | |
Publication status | Published - 2011 |
Equipment
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Centre for Electron Microscopy (MCEM)
Sorrell, F. (Manager) & Miller, P. (Manager)
Office of the Vice-Provost (Research and Research Infrastructure)Facility/equipment: Facility