Improved in vivo magnetic resonance imaging of acute myocardial infarction after intravenous paramagnetic contrast agent administration

AbstractThe aim of this study was to investigate the merits of magnetic resonance imaging (MRI) using an elastin-binding contrast agent after myocardial infarction in mouse models with deletions of monocyte populations. Permanent ligation of the left anterior descending (LAD) artery was conducted in 10 wild-type mice and 10 each of three knockout models: CX3CR−/−, CCR2−/−, and MCP-1−/−. At 7 days and 30 days after permanent ligation, cardiac MRI was performed with a 7 T-Bruker horizontal scanner for in vivo detection of elastin with an elastin/tropoelastin-specific contrast agent (ESMA). Histology was performed with staining for elastin, collagen I and III, and F4/80. Real-time PCR was conducted to quantify the expression of genes for collagen I and III, F4/80, and tumor necrosis factor alpha (TNFα). Histological and ESMA-indicated elastin areas were strongly correlated (r = 0.8). 30 days after permanent ligation, CCR2-deficient mice demonstrated higher elastin levels in the scar relative to MCP-1−/− (p < 0.04) and wild-type mice (p < 0.02). The ejection fraction was lower in CCR2-deficient mice. In vivo MRI in mouse models of MI can detect elastin deposition after myocardial infarction, highlighting the pivotal role of elastin in myocardial remodeling in mouse models with deletions of monocyte populations.

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106 In vivo quantification of absolute perfusion in mice with myocardial infarction by spin labelling magnetic resonance imaging

European Heart Journal ◽

10.1016/s0195-668x(03)93657-8 ◽

2003 ◽

Vol 24 (5) ◽

pp. 4

Author(s):

M NAHRENDORF

Keyword(s):

Magnetic Resonance Imaging ◽

Myocardial Infarction ◽

Magnetic Resonance ◽

Resonance Imaging ◽

Spin Labelling

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Silica-Coated Fe3O4 Nanoparticles as a Bifunctional Agent for Magnetic Resonance Imaging and ZnII Fluorescent Sensing

Technology in Cancer Research & Treatment ◽

10.1177/15330338211036539 ◽

2021 ◽

Vol 20 ◽

pp. 153303382110365

Author(s):

Lin Qiu ◽

Shuwen Zhou ◽

Ying Li ◽

Wen Rui ◽

Pengfei Cui ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Contrast Agent ◽

Quantum Interference ◽

Inductively Coupled Plasma ◽

Fluorescence Emission ◽

Mri Contrast Agent ◽

Core Shell ◽

Resonance Imaging

Bifunctional magnetic/fluorescent core-shell silica nanospheres (MNPs) encapsulated with the magnetic Fe3O4 core and a derivate of 8-amimoquinoline (N-(quinolin-8-yl)-2-(3-(triethoxysilyl) propylamino) acetamide) (QTEPA) into the shell were synthesized. These functional MNPs were prepared with a modified stöber method and the formed Fe3O4@SiO2-QTEPA core-shell nanocomposites are biocompatible, water-dispersible, and stable. These prepared nanoparticles were characterized by X-ray power diffraction (XRD), transmission electron microscopy (TEM), thermoelectric plasma Quad II inductively coupled plasma mass spectrometry (ICP-MS), superconducting quantum interference device (SQUID), TG/DTA thermal analyzer (TGA) and Fourier transform infrared spectroscopy (FTIR). Further application of the nanoparticles in detecting Zn2+ was confirmed by the fluorescence experiment: the nanosensor shows high selectivity and sensitivity to Zn2+ with a 22-fold fluorescence emission enhancement in the presence of 10 μM Zn2+. Moreover, the transverse relaxivity measurements show that the core-shell MNPs have T2 relaxivity (r2) of 155.05 mM−1 S−1 based on Fe concentration on the 3.0 T scanner, suggesting that the compound can be used as a negative contrast agent for MRI. Further in vivo experiments showed that these MNPs could be used as MRI contrast agent. Therefore, the new nanosensor provides the dual modality of magnetic resonance imaging and optical imaging.

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