Journal: International Journal of Molecular Sciences

Article Title: Design of Superparamagnetic Nanoparticles for Magnetic Particle Imaging (MPI)

doi: 10.3390/ijms140918682

Figure Lengend Snippet: Principle of MPI configuration [ , ]. ( a ) The magnetization curve ( M ) of the superparamagnetic nanoparticles is nonlinear. When an oscillating magnetic field (modulation field) with a single frequency, f 1 , is applied to the superparamagnetic nanoparticles, the resulting magnetization, M ( t ), is time-dependent and exhibits higher harmonics. The Fourier-transformed signals ( S ) with higher harmonics (grey box) are used for MPI imaging. The signal at f 1 is excluded, because it is difficult to isolate from the superimposed modulation field signal; ( b ) When a time-independent field is superimposed upon the modulation field, the nanoparticle magnetization is always in saturation and does not significantly respond to the modulation field. The Fourier-transformed signals ( S ) are nearly non-existent; ( c ) The selection field, covering the whole region of interest (ROI), provides a field-free point (FFP). It can be produced by two magnets in Maxwell configuration.

Article Snippet: Nevertheless, for the commercially available SPIO nanoparticle agents (e.g., Resovist and Feridex (AMAG Pharmaceuticals, Lexington, MA, USA)), it was estimated that only ~3% of the ensemble exhibits the optimal nanoparticle size and can contribute to significant MPI signals [ , , ].

Techniques: Transformation Assay, Imaging, Selection, Produced

Journal: International Journal of Molecular Sciences

Article Title: Design of Superparamagnetic Nanoparticles for Magnetic Particle Imaging (MPI)

doi: 10.3390/ijms140918682

Figure Lengend Snippet: Magnetization for magnetite (Fe O 4 ) nanoparticles that are exposed to a 10 mT magnetic field, at 50 kHz. ( a ) Time-dependent magnetization ( M ( t ) ) versus nanoparticle diameters; and ( b ) M ( t ) for increasing nanoparticle size distribution, with the median diameter being 14 nm. Reprinted with permission from .

Article Snippet: Nevertheless, for the commercially available SPIO nanoparticle agents (e.g., Resovist and Feridex (AMAG Pharmaceuticals, Lexington, MA, USA)), it was estimated that only ~3% of the ensemble exhibits the optimal nanoparticle size and can contribute to significant MPI signals [ , , ].

Techniques:

Journal: International Journal of Molecular Sciences

Article Title: Design of Superparamagnetic Nanoparticles for Magnetic Particle Imaging (MPI)

doi: 10.3390/ijms140918682

Figure Lengend Snippet: TEM image of red blood cells (RBCs) labeled by ( a ) citrate-coated superparamagnetic iron oxide (SPIO) nanoparticles; ( b ) Resovist (SHU 555A); ( c ) Sinerem (AMI 227); ( d ) PMP-50 and ( e ) P904, respectively; ( f ) MPI images (orange), displaying a sagittal slice through heart, were overlapped onto MRI reference images. MPI data was acquired 3 h and 24 h after injection of Resovist-loaded RBCs. Reprinted with permission: ( a ) from ; ( b ), ( c ) and ( d ) from ; ( e ) from ; and ( f ) from .

Article Snippet: Nevertheless, for the commercially available SPIO nanoparticle agents (e.g., Resovist and Feridex (AMAG Pharmaceuticals, Lexington, MA, USA)), it was estimated that only ~3% of the ensemble exhibits the optimal nanoparticle size and can contribute to significant MPI signals [ , , ].

Techniques: Labeling, Injection

Journal: International Journal of Molecular Sciences

Article Title: Design of Superparamagnetic Nanoparticles for Magnetic Particle Imaging (MPI)

doi: 10.3390/ijms140918682

Figure Lengend Snippet: ( a – c ) Plaque histological sections. ( a ) Perls’ staining shows positive iron oxide accumulation (arrow; original magnification ×100) in the plaque fibrous cap; ( b ) MAC 387 stain shows the accumulation of macrophages (arrows) in the cap region of plaque (magnification ×200); ( c ) Double staining with MAC 387 antibody (red) and Perls’ reagent (blue) demonstrates colocalization of SPIO nanoparticles (Sinerem) to macrophages (magnification ×1000); ( d – i ) Axial MRI images show the same section of a patient’s internal carotid artery at different times. The corresponding histological section was obtained eight days after the infusion and, then, was stained with elastin van Gieson; ( d ) Before infusion of Sinerem, the fibrous cap visualized with no signal loss; ( e ) At 24 h after infusion, a signal loss area (arrow) is shown in the subendothelial region; ( f , g ) The size of the signal loss area has increased at ( f ) 36 h and ( g ) 48 h after infusion; ( h ) After 96 h of infusion, the signal loss area is still visible, but decreased; ( i ) The histological section of plaque shows a thin fibrous cap (black arrow) and a large lipid core (yellow arrow) that are both typical features of vulnerable plaque. Reprinted with permission from .

Article Snippet: Nevertheless, for the commercially available SPIO nanoparticle agents (e.g., Resovist and Feridex (AMAG Pharmaceuticals, Lexington, MA, USA)), it was estimated that only ~3% of the ensemble exhibits the optimal nanoparticle size and can contribute to significant MPI signals [ , , ].

Techniques: Staining, Double Staining

Journal: International Journal of Molecular Sciences

Article Title: Design of Superparamagnetic Nanoparticles for Magnetic Particle Imaging (MPI)

doi: 10.3390/ijms140918682

Figure Lengend Snippet: ( A ) SPIO nanoparticles diffusely distributed in T-cells after the T-cells being labeled with SPIO nanoparticles (1 mM Fe/mL) for 1 h (A1) and 4 h (A2); ( B ) Fifth/third harmonic ratio versus log of viscosity for Feridex dispersed in glycerol solutions with different mass concentrations. Nanoparticle excitation occurred at alternating magnetic field (AMF) (224 Hz, 10 mT). Reprinted with permission: ( A ) from ; and ( B ) from .

Article Snippet: Nevertheless, for the commercially available SPIO nanoparticle agents (e.g., Resovist and Feridex (AMAG Pharmaceuticals, Lexington, MA, USA)), it was estimated that only ~3% of the ensemble exhibits the optimal nanoparticle size and can contribute to significant MPI signals [ , , ].

Techniques: Labeling, Viscosity