Tunable and noncytotoxic PET/SPECT-MRI multimodality imaging probes using colloidally stable ligand-free superparamagnetic iron oxide nanoparticles.
Physiologically stable multimodality imaging probes for positron emission tomography/single-photon emission computed tomography (PET/SPECT)-magnetic resonance imaging (MRI) were synthesized using the superparamagnetic maghemite iron oxide (γ-Fe2O3) nanoparticles (SPIONs). The SPIONs were sterically stabilized with a finely tuned mixture of diblock copolymers with either methoxypolyethylene glycol (MPEG) or primary amine NH2end groups. The radioisotope for PET or SPECT imaging was incorporated with the SPIONs at high temperature.57Co2+ions with a long half-life of 270.9 days were used as a model for the radiotracer to study the kinetics of radiolabeling, characterization, and the stability of the radiolabeled SPIONs. Radioactive67Ga3+and Cu2+-labeled SPIONs were also produced successfully using the optimized conditions from the57Co2+-labeling process. No free radioisotopes were detected in the aqueous phase for the radiolabeled SPIONs 1 week after dispersion in phosphate-buffered saline (PBS). All labeled SPIONs were not only well dispersed and stable under physiological conditions but also noncytotoxic in vitro. The ability to design and produce physiologically stable radiolabeled magnetic nanoparticles with a finely controlled number of functionalizable end groups on the SPIONs enables the generation of a desirable and biologically compatible multimodality PET/SPECT-MRI agent on a single T2 contrast MRI probe.
Key Centre for Polymers and Colloids, School of Chemistry, University of Sydney.
Th Nguyen
TN
Pham
Radioisotopes and Radiotracers, NSTLI, Australian Nuclear Science and Technology Organisation, Sydney.
Nigel A
NA
Lengkeek
Radioisotopes and Radiotracers, NSTLI, Australian Nuclear Science and Technology Organisation, Sydney.
Ivan
I
Greguric
Key Centre for Polymers and Colloids, School of Chemistry, University of Sydney.
Byung J
BJ
Kim
Radioisotopes and Radiotracers, NSTLI, Australian Nuclear Science and Technology Organisation, Sydney.
Paul A
PA
Pellegrini
Sirtex Medical Limited, North Sydney, NSW, Australia.
Stephanie A
SA
Bickley
Sirtex Medical Limited, North Sydney, NSW, Australia.
Marcel R
MR
Tanudji
Sirtex Medical Limited, North Sydney, NSW, Australia.
Stephen K
SK
Jones
Key Centre for Polymers and Colloids, School of Chemistry, University of Sydney.
Brian S
BS
Hawkett
Key Centre for Polymers and Colloids, School of Chemistry, University of Sydney.
Binh Tt
BT
Pham
D041721:3T3-L1 Cells; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003102:Colloids / Q000737:chemistry*; D003911:Dextrans / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D008024:Ligands; D008279:Magnetic Resonance Imaging / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D051379:Mice; D064847:Multimodal Imaging / Q000379:methods*; D032446:Myoblasts / Q000166:cytology / Q000187:drug effects; D011092:Polyethylene Glycols; D049268:Positron-Emission Tomography / Q000379:methods*; D051381:Rats; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D003102:Colloids; D003911:Dextrans; D005290:Ferric Compounds; D008024:Ligands; D058185:Magnetite Nanoparticles; C000499:ferric oxide; D011092:Polyethylene Glycols; C028210:monomethoxypolyethylene glycol
SPIONs; magnetic resonance imaging; positron emission tomography; radiolabeling; single-photon emission computed tomography