scholarly journals Precise Study on Size-Dependent Properties of Magnetic Iron Oxide Nanoparticles for In Vivo Magnetic Resonance Imaging

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Ling Chen ◽  
Jun Xie ◽  
Haoan Wu ◽  
Jianzhong Li ◽  
Zhiming Wang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Properties ◽  
Iron Oxide ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Mri Contrast Agent ◽  
Iron Oxide Nanoparticle ◽  
Resonance Imaging ◽  
Magnetic Iron Oxide

Developing a biocompatible contrast agent with high stability and favorable magnetism for sensitive detection of malignant tumors using magnetic resonance imaging (MRI) remains a great demand in clinical. Nowadays, the fine control of magnetic iron oxide nanoparticle (MION) sizes from a few nanometers to dozens of nanometers can be realized through a thermal decomposition method of iron precursors. This progress allows us to research accurately on the size dependence of magnetic properties of MION, involving saturation magnetization (Ms), specific absorption rate (SAR), and relaxivity. Here, we synthesized MION in a size range between 14 and 26 nm and modified them with DSPE-PEG2000 for biomedical use. The magnetic properties of PEGylated MION increased monotonically with MION size, while the nonspecific uptake of MION also enhanced with size through cell experiments. The MION with the size of 22 nm as a T2-weighted contrast agent presented the best contrast-enhancing effect comparing with other sizes in vivo MRI of murine tumor. Therefore, the MION of 22 nm may have potential to serve as an ideal MRI contrast agent for tumor detection.

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

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.

scholarly journals Monitoring ferumoxide-labelled neural progenitor cells and lesion evolution by magnetic resonance imaging in a model of cell transplantation in cerebral ischaemia

F1000Research ◽  
2014 ◽  
Vol 2 ◽  
pp. 252
Author(s):  
Rachael A Panizzo ◽  
David G Gadian ◽  
Jane C Sowden ◽  
Jack A Wells ◽  
Mark F Lythgoe ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Cerebral Ischaemia ◽  
Mri Contrast Agent ◽  
Lesion Volume ◽  
Mri Imaging ◽  
Resonance Imaging ◽  
Protamine Sulphate

Efficacy of neural stem/progenitor cell (NPC) therapies after cerebral ischaemia could be better evaluated by monitoring in vivo migration and distribution of cells post-engraftment in parallel with analysis of lesion volume and functional recovery. Magnetic resonance imaging (MRI) is ideally placed to achieve this, but still poses several challenges. We show that combining the ferumoxide MRI contrast agent Endorem with protamine sulphate (FePro) improves iron oxide uptake in cells compared to Endorem alone and is non-toxic. Hence FePro complex is a better contrast agent than Endorem for monitoring NPCs. FePro complex-labelled NPCs proliferated and differentiated normally in vitro, and upon grafting into the brain 48 hours post-ischaemia they were detected in vivo by MRI. Imaging over four weeks showed the development of a confounding endogenous hypointense contrast evolution at later timepoints within the lesioned tissue. This was at least partly due to accumulation within the lesion of macrophages and endogenous iron. Neither significant NPC migration, assessed by MRI and histologically, nor a reduction in the ischaemic lesion volume was observed in NPC-grafted brains.  Crucially, while MRI provides reliable information on engrafted cell location early after an ischaemic insult, pathophysiological changes to ischaemic lesions can interfere with cellular imaging at later timepoints.

scholarly journals Monitoring ferumoxide-labelled neural progenitor cells and lesion evolution by magnetic resonance imaging in a model of cell transplantation in cerebral ischaemia

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 252 ◽  
Author(s):  
Rachael A Panizzo ◽  
David G Gadian ◽  
Jane C Sowden ◽  
Jack A Wells ◽  
Mark F Lythgoe ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Cerebral Ischaemia ◽  
Mri Contrast Agent ◽  
Lesion Volume ◽  
Mri Imaging ◽  
Resonance Imaging ◽  
Protamine Sulphate

Efficacy of neural stem/progenitor cell (NPC) therapies after cerebral ischaemia could be better evaluated by monitoring in vivo migration and distribution of cells post-engraftment in parallel with analysis of lesion volume and functional recovery. Magnetic resonance imaging (MRI) is ideally placed to achieve this, but still poses several challenges. We show that combining the ferumoxide MRI contrast agent Endorem with protamine sulphate (FePro) improves iron oxide uptake in cells compared to Endorem alone and is non-toxic. Hence FePro complex is a better contrast agent than Endorem for monitoring NPCs. FePro complex-labelled NPCs proliferated and differentiated normally in vitro, and upon grafting into the brain 48 hours post-ischaemia they were detected in vivo by MRI. Imaging over four weeks showed the development of a confounding endogenous hypointense contrast evolution at later timepoints within the lesioned tissue. This was at least partly due to accumulation within the lesion of macrophages and endogenous iron. Neither significant NPC migration, assessed by MRI and histologically, nor a reduction in the ischaemic lesion volume was observed in NPC-grafted brains.  Crucially, while MRI provides reliable information on engrafted cell location early after an ischaemic insult, pathophysiological changes to ischaemic lesions can interfere with cellular imaging at later timepoints.

Magnetic Iron Oxide Nanoparticle Labeling of Photoreceptor Precursors for Magnetic Resonance Imaging

2019 ◽  
Vol 25 (9) ◽  
pp. 532-542
Author(s):  
Dae Joong Ma ◽  
Mi-Sun Lim ◽  
Un Chul Park ◽  
Jung-Bum Park ◽  
So Yeon Ji ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Iron Oxide ◽  
Magnetic Resonance ◽  
Iron Oxide Nanoparticle ◽  
Resonance Imaging ◽  
Magnetic Iron Oxide ◽  
Oxide Nanoparticle

Abstract 1935: A Magnetic Resonance Imaging Contrast Agent Targeted Towards Activated Platelets Allows In Vivo Detection of Thrombosis and Monitoring of Thrombolysis

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Constantin von zur Muehlen ◽  
Dominik Elverfeldt ◽  
Julia Moeller ◽  
Robin Choudhury ◽  
Christoph Hagemeyer ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Iron Oxide ◽  
Magnetic Resonance ◽  
Carotid Artery ◽  
Contrast Agent ◽  
Resonance Imaging ◽  
Non Invasive ◽  
Activated Platelets ◽  
Signal Void

Platelets are the key to thrombus formation in atherothrombosis and play a major role in plaque rupture. Non-invasive imaging of activated platelets would be of great clinical interest. Here, we evaluate the ability of a magnetic resonance imaging (MRI) contrast agent consisting of microparticles of iron oxide (MPIO) and a single-chain antibody targeting ligand-induced binding sites (LIBS) on activated GPIIb/IIIa to image carotid artery thrombosis and. Anti-LIBS or control antibody were conjugated to 1μm-sized MPIOs (LIBS-MPIO/control-MPIO). Non-occlusive wall-adherent thrombi were induced in BL/6 mice using 6% ferric chloride. MRI (at 9.4 Tesla) of the carotid artery was performed once before (figure , A) and repeatedly in 12min long sequences after LIBS-MPIO/control-MPIO injection. After 36min, a significant signal void, which is the typical effect of iron oxide-based contrast agents, was observed with LIBS-MPIO (figure , B), but not control-MPIO (P<0.01) and corresponded to LIBS-MPIO binding as confirmed by histology. After thrombolysis, in LIBS-MPIO injected mice the signal void subsided, indicating successful thrombolysis (figure , C). On histology, MPIO-content of thrombus, as well as thrombus size, correlated significantly with LIBS-MPIO-induced signal void (both P<0.01). LIBS-MPIO allows in vivo MRI of activated platelets with excellent contrast properties and monitoring of thrombolytic therapy. This approach represents a novel non-invasive technique allowing rapid detection and quantification of platelet-containing thrombi, such as found on the surface of ruptured atherosclerotic plaques.

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