Journal: International Journal of Nanomedicine

Article Title: Optimization of molecularly targeted MRI in the brain: empirical comparison of sequences and particles

doi: 10.2147/IJN.S158071

Figure Lengend Snippet: ( A ) Representative in vivo images of mice 13 h post-VCAM-USPIO injection at different magnetic fields. Three sequences of MGE3D, GE3D, and bSSFP3D are shown from a 3D dataset. Hypointensities were detected in both hemispheres of the brains. ( B – D ) Histological assessment of VCAM upregulation at the injection side. Notes: Green vessels show unilateral upregulation of VCAM, nuclei are shown in blue. Scale bar: 1 mm. Abbreviations: bSSFP3D, balanced steady-state free precession 3D; GE3D, gradient echo 3D; MGE3D, multi-gradient echo 3D; USPIO, ultra-small superparamagnetic iron oxide; VCAM, vascular cell adhesion molecule.

Article Snippet: To determine the blood half-life of VCAM-MPIO and VCAM-USPIO, the particles were injected via a tail vein into female BALB/c mice (6–7 weeks old, n=15, Charles River, UK, Kent, UK) at a constant dose of 4 mg Fe/kg in 100 μL sterile PBS.

Techniques: In Vivo, Injection

Journal: International Journal of Nanomedicine

Article Title: Optimization of molecularly targeted MRI in the brain: empirical comparison of sequences and particles

doi: 10.2147/IJN.S158071

Figure Lengend Snippet: Quantitative comparison of MGE3D (■), GE3D (□), and bSSFP3D ([img]) sequences for detection of MPIO and USPIO at different magnetic field strengths. Note: MGE3D yielded significantly higher SNR ( A , C ) and CNR ( B , D ) compared with other sequences at all field strengths for both MPIO and USPIO detection (* P <0.05, ** P <0.01, *** P <0.001). Abbreviations: bSSFP3D, balanced steady-state free precession 3D; CNR, contrast-to-noise ratio; GE3D, gradient echo 3D; MGE3D, multi-gradient echo 3D; MPIO, microparticles of iron oxide; SNR, signal-to-noise ratio; USPIO, ultra-small superparamagnetic iron oxide; VCAM, vascular cell adhesion molecule.

Article Snippet: To determine the blood half-life of VCAM-MPIO and VCAM-USPIO, the particles were injected via a tail vein into female BALB/c mice (6–7 weeks old, n=15, Charles River, UK, Kent, UK) at a constant dose of 4 mg Fe/kg in 100 μL sterile PBS.

Techniques:

Journal: International Journal of Nanomedicine

Article Title: Optimization of molecularly targeted MRI in the brain: empirical comparison of sequences and particles

doi: 10.2147/IJN.S158071

Figure Lengend Snippet: ( A ) Graph showing quantitation of MPIO- and USPIO-induced hypointensities in injected (green bar) and contralateral (blue bar) hemispheres using MGE3D sequence. Baseline level of endogenous hypointensities is shown with the dotted line. A significant difference was evident between the 2 hemispheres for VCAM-MPIO-injected mice at all field strengths. No significant difference was found for VCAM-USPIO. N=4 per group; * P <0.05, ** P <0.01. ( B ) Histological staining for VCAM-1 (brown) and iron beads (Perls’ Prussian blue) demonstrating upregulation of VCAM-1 on endothelial cells together with VCAM-MPIO binding (arrows). VCAM-USPIO was not detected in brain samples after perfusion, error bar=50 um ( C ) Graph showing the decay curve of the biological clearance of VCAM-MPIO and VCAM-USPIO, at a constant dose of 4 mg Fe/kg of body weight over time after injection. Graph shows T 2 relaxivity values of blood samples at different time points after administration. Curve is fitted as a single-phase exponential decay constrained to a plateau at the average naïve blood sample values (baseline; dotted lines). ( D ) MGE3D images of mice injected with VCAM-USPIO at different time-points acquired at 7.0 T – images show the presence of VCAM-USPIO in an inflammation model (top row) and naïve mouse (bottom row) at 1 and 13 h after contrast agent administration. No signal was detected 80 h after injection in both cohorts. Abbreviations: MGE3D, multi-gradient echo 3D; MPIO, microparticles of iron oxide; USPIO, ultra-small superparamagnetic iron oxide; VCAM, vascular cell adhesion molecule.

Article Snippet: To determine the blood half-life of VCAM-MPIO and VCAM-USPIO, the particles were injected via a tail vein into female BALB/c mice (6–7 weeks old, n=15, Charles River, UK, Kent, UK) at a constant dose of 4 mg Fe/kg in 100 μL sterile PBS.

Techniques: Quantitation Assay, Injection, Sequencing, Staining, Binding Assay