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.

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 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.

FULVIC ACID COATED IRON OXIDE NANOPARTICLES FOR MAGNETIC RESONANCE IMAGING CONTRAST AGENT

2010 ◽  
Vol 03 (03) ◽  
pp. 197-200 ◽  
Author(s):  
CHUNJIAO ZHOU ◽  
PENGFEI RONG ◽  
WENJIE ZHANG ◽  
JIANDA ZHOU ◽  
QINGLIN ZHANG ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Fulvic Acid ◽  
Superparamagnetic Nanoparticles ◽  
Mri Contrast Agent ◽  
Hydroxyl Groups ◽  
Resonance Imaging ◽  
Magnetic Resonance Imaging Contrast ◽  
Magnetic Resonance Imaging Mri

Fulvic acid coated Fe 3 O 4 superparamagnetic nanoparticles were synthesized by a coprecipitation technique with iron salts and a small molecule stabilizer-fulvic acid. The prepared nanoparticles were well dispersed in water with about 10 nm in size according to transmission electron microscopy (TEM) observations. Fourier transform infrared spectroscopy (FTIR) revealed that fulvic acid were successfully covalently bonded to Fe 3 O 4 through the two adjacent phenolic hydroxyl groups and the carboxyl (- COOH ) groups were functionalized to the surface. The vibrating sample magnetometer (VSM) result showed that the nanoparticles were superparamagnetic and the saturation magnetizations were 60 emu/g. Moreover, their efficacy of liver magnetic resonance imaging (MRI) contrast agent was investigated by using live rat and tumor-bearing rabbit models through conventional clinical 1.5T MRI.

Experimental Otitis Media Evaluated by Magnetic Resonance Imaging: An in Vivo Model

1992 ◽  
Vol 101 (3) ◽  
pp. 248-254 ◽  
Author(s):  
Kenny H. Chan ◽  
William J. Doyle ◽  
J. Douglas Swarts ◽  
David Kardatzke ◽  
Yoshie Hashida ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Otitis Media ◽  
Middle Ear ◽  
Washout Rate ◽  
In Vivo Model ◽  
Resonance Imaging ◽  
Middle Ear Mucosa

The use of magnetic resonance imaging in otitis media research is being explored in our laboratory. In this study, we present a new method for studying changes in the middle ear cleft due to an episode of induced otitis media in the chinchilla model. It uses gadolinium-diethylenetriamine pentaacetic acid, a magnetic resonance imaging contrast agent, to examine the uptake and washout characteristics of middle ear mucosa during an inflammatory episode. Parameters such as the time to maximum intensity of the mucosa and the washout rate of the contrast agent from the mucosa were significantly correlated to the duration of the infection.

A dendronized heparin–gadolinium polymer self-assembled into a nanoscale system as a potential magnetic resonance imaging contrast agent

2016 ◽  
Vol 7 (14) ◽  
pp. 2531-2541 ◽  
Author(s):  
Chunhua Guo ◽  
Ling Sun ◽  
Wenchuan She ◽  
Ning Li ◽  
Lei Jiang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Mri Contrast Agent ◽  
Resonance Imaging ◽  
Mri Contrast ◽  
Nanoscale System ◽  
Magnetic Resonance Imaging Contrast ◽  
Self Assembled ◽  
Imaging Contrast Agent

An amphiphilic dendronized heparin–gadolinium conjugate self-assembles into a nanoscale system by a combination of the features of the nanoparticle, dendrimer and heparin. The nanoscale system demonstrates great potential as an efficient and safe MRI contrast agent.

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