scholarly journals Iron Oxide as an Mri Contrast Agent for Cell Tracking: Supplementary Issue

2015 ◽  
Vol 8s1 ◽  
pp. MRI.S23557 ◽  
Author(s):  
Daniel J. Korchinski ◽  
May Taha ◽  
Runze Yang ◽  
Nabeela Nathoo ◽  
Jeff F. Dunn

Iron oxide contrast agents have been combined with magnetic resonance imaging for cell tracking. In this review, we discuss coating properties and provide an overview of ex vivo and in vivo labeling of different cell types, including stem cells, red blood cells, and monocytes/macrophages. Furthermore, we provide examples of applications of cell tracking with iron contrast agents in stroke, multiple sclerosis, cancer, arteriovenous malformations, and aortic and cerebral aneurysms. Attempts at quantifying iron oxide concentrations and other vascular properties are examined. We advise on designing studies using iron contrast agents including methods for validation.

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christian E. Anderson ◽  
Mette Johansen ◽  
Bernadette O. Erokwu ◽  
He Hu ◽  
Yuning Gu ◽  
...  

AbstractSynchronous assessment of multiple MRI contrast agents in a single scanning session would provide a new “multi-color” imaging capability similar to fluorescence imaging but with high spatiotemporal resolution and unlimited imaging depth. This multi-agent MRI technology would enable a whole new class of basic science and clinical MRI experiments that simultaneously explore multiple physiologic/molecular events in vivo. Unfortunately, conventional MRI acquisition techniques are only capable of detecting and quantifying one paramagnetic MRI contrast agent at a time. Herein, the Dual Contrast – Magnetic Resonance Fingerprinting (DC-MRF) methodology was extended for in vivo application and evaluated by simultaneously and dynamically mapping the intra-tumoral concentration of two MRI contrast agents (Gd-BOPTA and Dy-DOTA-azide) in a mouse glioma model. Co-registered gadolinium and dysprosium concentration maps were generated with sub-millimeter spatial resolution and acquired dynamically with just over 2-minute temporal resolution. Mean tumor Gd and Dy concentration measurements from both single agent and dual agent DC-MRF studies demonstrated significant correlations with ex vivo mass spectrometry elemental analyses. This initial in vivo study demonstrates the potential for DC-MRF to provide a useful dual-agent MRI platform.


2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai

The purpose of this study is to establish the minimal injection doses of magnetic resonance imaging (MRI) contrast agents that can achieve optimized images while improving the safety of injectable MRI drugs. Gadolinium-diethylenetriamine penta-acetic acid (Gd-DTPA) and ferucarbotran, commonly used in clinical practice, were selected and evaluated with in vitro and in vivo experiments. MRI was acquired using T1-weighted (T1W) and T2-weighted (T2W) sequences, and the results were quantitatively analyzed. For in vitro experiments, results showed that T1W and T2W images were optimal when Gd-DTPA-bisamide (2-oxoethyl) (Gd-DTPA-BMEA) and ferucarbotran were diluted to a volume percentage of 0.6% and 0.05%; all comparisons were significant differences in grayscale statistics using one-way analysis of variance (ANOVA). For in vivo experiments, the contrast agent with optimal concentration percentages determined from in vitro experiments were injected into mice with an injection volume of 100 μL, and the images of brain, heart, liver, and mesentery before and after injection were compared. The statistical results showed that the p values of both T1W and T2W were less than 0.001, which were statistically significant. Under safety considerations for MRI contrast agent injection, optimized MRI images could still be obtained after reducing the injection concentration, which can provide a reference for the safety concentrations of MRI contrast agent injection in the future.


2015 ◽  
Vol 112 (21) ◽  
pp. 6607-6612 ◽  
Author(s):  
Shenghui Xue ◽  
Hua Yang ◽  
Jingjuan Qiao ◽  
Fan Pu ◽  
Jie Jiang ◽  
...  

With available MRI techniques, primary and metastatic liver cancers that are associated with high mortality rates and poor treatment responses are only diagnosed at late stages, due to the lack of highly sensitive contrast agents without Gd3+ toxicity. We have developed a protein contrast agent (ProCA32) that exhibits high stability for Gd3+ and a 1011-fold greater selectivity for Gd3+ over Zn2+ compared with existing contrast agents. ProCA32, modified from parvalbumin, possesses high relaxivities (r1/r2: 66.8 mmol−1⋅s−1/89.2 mmol−1⋅s−1 per particle). Using T1- and T2-weighted, as well as T2/T1 ratio imaging, we have achieved, for the first time (to our knowledge), robust MRI detection of early liver metastases as small as ∼0.24 mm in diameter, much smaller than the current detection limit of 10–20 mm. Furthermore, ProCA32 exhibits appropriate in vivo preference for liver sinusoidal spaces and pharmacokinetics for high-quality imaging. ProCA32 will be invaluable for noninvasive early detection of primary and metastatic liver cancers as well as for monitoring treatment and guiding therapeutic interventions, including drug delivery.


Nanoscale ◽  
2014 ◽  
Vol 6 (16) ◽  
pp. 9646-9654 ◽  
Author(s):  
Daniel Nordmeyer ◽  
Patrick Stumpf ◽  
Dominic Gröger ◽  
Andreas Hofmann ◽  
Sven Enders ◽  
...  

Superparamagnetic iron oxide nanoparticles with a dendritic polyglycerol (dPG) sulfate strongly bind to L- and P-selectin. Shielding of leukocytes reduces cell extravasation and binding to endothelial cells indicate inflammation specificity and thus, applicability as selective MRI contrast agent.


2021 ◽  
Author(s):  
Joong Kim ◽  
Wen-Tung Wang ◽  
Andrew Knutsen ◽  
David Brody

Abstract There have been substantial efforts to develop targeted exogenous MRI contrast agents to assess specific brain pathologies. In parallel with other efforts, it is important to assess the sensitivity of candidate MRI methods for detection of contrast agents. Here, we propose a digital simulation approach, which includes MR relaxation (R1 and R2) mapping and image co-registration. We simulated the effects of 3 nm iron oxide nanoparticles (IONPs) as a model contrast agent. Two independent relaxation maps acquired from the brain of the same subject were co-registered. The baseline subtraction between the two relaxation maps showed good agreement, demonstrating the high reproducibility of the method. Next, the second relaxation map was digitally altered (“seeded”) to simulate additional MR relaxation values corresponding to several concentrations of 3 nm IONPs in various locations. The maps of absolute differences between the first relaxation map and the digitally altered second relaxation maps were assessed for conspicuity. Results based on living mouse and human brains scanned at 9.4 T and 3.0 T respectively both indicated reliable conspicuity for signal equivalent to 0.06 mM IONP or higher. Overall, the digital simulation approach is a useful method to improve the development of MRI contrast agents and accompanying MRI methodologies.


2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Hyeona Yim ◽  
Seogjin Seo ◽  
Kun Na

Various imaging technologies have become increasingly important in developing a better understanding of information on the biological and clinical phenomena associated with diseases of interest. Of these technologies, magnetic resonance imaging (MRI) is one of the most powerful for clinical diagnosis and in vivo imaging without the exposure to ionising radiation or radiotracers. Despite its many advantages, there are intrinsic limitations caused by MRI contrast agents, such as short vascular half-life circulation, which lead to unwanted side effects. In this review, we will focus on the multifunctional modification of MRI contrast agents for diagnosis and therapy.


2021 ◽  
Vol 118 (32) ◽  
pp. e2110344118
Author(s):  
Weiran Feng ◽  
Zhen Cao ◽  
Pei Xin Lim ◽  
Huiyong Zhao ◽  
Hanzhi Luo ◽  
...  

The increasing complexity of different cell types revealed by single-cell analysis of tissues presents challenges in efficiently elucidating their functions. Here we show, using prostate as a model tissue, that primary organoids and freshly isolated epithelial cells can be CRISPR edited ex vivo using Cas9–sgRNA (guide RNA) ribotnucleoprotein complex technology, then orthotopically transferred in vivo into immunocompetent or immunodeficient mice to generate cancer models with phenotypes resembling those seen in traditional genetically engineered mouse models. Large intrachromosomal (∼2 Mb) or multigenic deletions can be engineered efficiently without the need for selection, including in isolated subpopulations to address cell-of-origin questions.


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