title: Iron oxide nanoparticle-micelles (ION-micelles) for sensitive (molecular) magnetic particle imaging and magnetic resonance imaging.
abstract: BACKGROUND
  Iron oxide nanoparticles (IONs) are a promising nanoplatform for contrast-enhanced MRI. Recently, magnetic particle imaging (MPI) was introduced as a new imaging modality, which is able to directly visualize magnetic particles and could serve as a more sensitive and quantitative alternative to MRI. However, MPI requires magnetic particles with specific magnetic properties for optimal use. Current commercially available iron oxide formulations perform suboptimal in MPI, which is triggering research into optimized synthesis strategies. Most synthesis procedures aim at size control of iron oxide nanoparticles rather than control over the magnetic properties. In this study, we report on the synthesis, characterization and application of a novel ION platform for sensitive MPI and MRI.
  
  
  RESULTS
  IONs were synthesized using a thermal-decomposition method and subsequently phase-transferred by encapsulation into lipidic micelles (ION-Micelles). Next, the material and magnetic properties of the ION-Micelles were analyzed. Most notably, vibrating sample magnetometry measurements showed that the effective magnetic core size of the IONs is 16 nm. In addition, magnetic particle spectrometry (MPS) measurements were performed. MPS is essentially zero-dimensional MPI and therefore allows to probe the potential of iron oxide formulations for MPI. ION-Micelles induced up to 200 times higher signal in MPS measurements than commercially available iron oxide formulations (Endorem, Resovist and Sinerem) and thus likely allow for significantly more sensitive MPI. In addition, the potential of the ION-Micelle platform for molecular MPI and MRI was showcased by MPS and MRI measurements of fibrin-binding peptide functionalized ION-Micelles (FibPep-ION-Micelles) bound to blood clots.
  
  
  CONCLUSIONS
  The presented data underlines the potential of the ION-Micelle nanoplatform for sensitive (molecular) MPI and warrants further investigation of the FibPep-ION-Micelle platform for in vivo, non-invasive imaging of fibrin in preclinical disease models of thrombus-related pathologies and atherosclerosis.
authors: Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
authors: Lucas W E
authors: LW
authors: Starmans
authors: Dirk
authors: D
authors: Burdinski
authors: Nicole P M
authors: NP
authors: Haex
authors: Rik P M
authors: RP
authors: Moonen
authors: Gustav J
authors: GJ
authors: Strijkers
authors: Klaas
authors: K
authors: Nicolay
authors: Holger
authors: H
authors: Grüll
mesh_terms: D000595:Amino Acid Sequence; D001777:Blood Coagulation; D003287:Contrast Media / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D005337:Fibrin / Q000737:chemistry; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D060306:Magnetometry; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010316:Particle Size; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D055767:Immobilized Proteins; D008055:Lipids; D058185:Magnetite Nanoparticles; D008823:Micelles; D010455:Peptides; C000499:ferric oxide; D005337:Fibrin