scholarly journals Magnetic resonance thermometry using a GdIII-based contrast agent

2021 ◽  
Vol 57 (14) ◽  
pp. 1770-1773
Author(s):  
S. A. Amali S. Subasinghe ◽  
Jonathan Romero ◽  
Cassandra L. Ward ◽  
Matthew D. Bailey ◽  
Donna R. Zehner ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Resonance Imaging ◽  
Magnetic Resonance Thermometry

The complexes described here serve as contrast agents for magnetic resonance imaging thermometry.

scholarly journals Polyaspartic Acid-Coated Paramagnetic Gadolinium Oxide Nanoparticles as a Dual-Modal T1 and T2 Magnetic Resonance Imaging Contrast Agent

2021 ◽  
Vol 11 (17) ◽  
pp. 8222
Author(s):  
Shanti Marasini ◽  
Huan Yue ◽  
Adibehalsadat Ghazanfari ◽  
Son Long Ho ◽  
Ji Ae Park ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Proton Spin ◽  
Water Proton ◽  
Resonance Imaging ◽  
Polyaspartic Acid ◽  
Mri Contrast ◽  
T1 And T2

Surface-coating polymers contribute to nanoparticle-based magnetic resonance imaging (MRI) contrast agents because they can affect the relaxometric properties of the nanoparticles. In this study, polyaspartic acid (PASA)-coated ultrasmall Gd2O3 nanoparticles with an average particle diameter of 2.0 nm were synthesized using the one-pot polyol method. The synthesized nanoparticles exhibited r1 and r2 of 19.1 and = 53.7 s−1mM−1, respectively, (r1 and r2 are longitudinal and transverse water–proton spin relaxivities, respectively) at 3.0 T MR field, approximately 5 and 10 times higher than those of commercial Gd-chelate contrast agents, respectively. The T1 and T2 MR images could be obtained due to an appreciable r2/r1 ratio of 2.80, indicating their potential as a dual-modal T1 and T2 MRI contrast agent.

scholarly journals Engineered ferritin nanocages as natural contrast agents in magnetic resonance imaging

RSC Advances ◽  
2017 ◽  
Vol 7 (55) ◽  
pp. 34892-34900 ◽  
Author(s):  
V. Nandwana ◽  
S.-R. Ryoo ◽  
S. Kanthala ◽  
A. Kumar ◽  
A. Sharma ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Magnetic Core ◽  
Mri Contrast Agent ◽  
Resonance Imaging ◽  
Mri Contrast

Here we report the development of a “natural” MRI contrast agent with tunable Fe loading and a magnetic core for magnetic resonance imaging.

scholarly journals A New Potential Contrast Agent for Magnetic Resonance Imaging: Iron Oxide-4A Nanocomposite

2019 ◽  
Author(s):  
L Zareei ◽  
B Divband ◽  
A Mesbahi ◽  
M Khatamian ◽  
A Kiani ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Iron Oxide ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Particle Diameter ◽  
Average Particle ◽  
Relaxation Rates ◽  
Resonance Imaging ◽  
T1 And T2

Background: Magnetic resonance imaging (MRI) contrast agents have an important role to differentiate healthy and diseased tissues. Access and design new contrast agents for the optimal use of MRI are necessary. This study aims to evaluate iron oxide–4A nanocomposite ability to act as a magnetic resonance imaging contrast agent.Materials and Methods: Iron oxide–4A nanocomposite (F4A) was synthesized. MTT assay was used to consider the nanocomposite safety for cell culture. The T1 and T2 relaxation times were measured using a 1.5 Tesla clinical MRI scanner. Then the corresponding relaxivities were determined.Results: The average particle diameter of the nanocomposite was 50 to 100 nm based on scanning electron microscope (SEM) image. A linear relationship between relaxation rates and the Fe concentration of the nanocomposite was obtained. The T1 and T2 relaxivities of the nanocomposite were calculated 5.413 and 1092.1 mM-1.s-1, respectively which led to the T2/T1 relaxivity ratioof 201.75.Conclusion: The high T2/T1 relaxivity ratio of the iron oxide–4A nanocomposite confirms it’s potential to act as a T2 contrast agent.

scholarly journals A New Potential Contrast Agent for Magnetic Resonance Imaging: Iron Oxide-4A Nanocomposite

2019 ◽  
Vol 9 (2Apr) ◽  
Author(s):  
L Zareei ◽  
B Divband ◽  
A Mesbahi ◽  
M Khatamian ◽  
A Kiani ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Iron Oxide ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Particle Diameter ◽  
Average Particle ◽  
Relaxation Rates ◽  
Resonance Imaging ◽  
T1 And T2

Background: Magnetic resonance imaging (MRI) contrast agents have an important role to differentiate healthy and diseased tissues. Access and design new contrast agents for the optimal use of MRI are necessary. This study aims to evaluate iron oxide–4A nanocomposite ability to act as a magnetic resonance imaging contrast agent.Materials and Methods: Iron oxide–4A nanocomposite (F4A) was synthesized. MTT assay was used to consider the nanocomposite safety for cell culture. The T1 and T2 relaxation times were measured using a 1.5 Tesla clinical MRI scanner. Then the corresponding relaxivities were determined.Results: The average particle diameter of the nanocomposite was 50 to 100 nm based on scanning electron microscope (SEM) image. A linear relationship between relaxation rates and the Fe concentration of the nanocomposite was obtained. The T1 and T2 relaxivities of the nanocomposite were calculated 5.413 and 1092.1 mM-1.s-1, respectively which led to the T2/T1 relaxivity ratioof 201.75.Conclusion: The high T2/T1 relaxivity ratio of the iron oxide–4A nanocomposite confirms it’s potential to act as a T2 contrast agent.

Tumor Environment-Responsive Degradable Branched Glycopolymer Magnetic Resonance Imaging Contrast Agent and Its Tumor-Targeted Imaging

2019 ◽  
Vol 15 (7) ◽  
pp. 1384-1400 ◽  
Author(s):  
Yang Wang ◽  
Yan Dai ◽  
Qiang Luo ◽  
Xiaoli Wei ◽  
Xueyang Xiao ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Signal Intensity ◽  
Tumor Targeting ◽  
Tumor Site ◽  
Resonance Imaging ◽  
Tumor Environment

Branched macromolecules have been used as carriers for imaging probes and drug delivery systems because of their tunable molecular structures, as well as their regular nanoscale structures and dimensions. We designed and synthesized two tumor environment-responsive branched and gadolinium (Gd)-based glycopolymer conjugates and investigated their potency as highly effective and safe magnetic resonance imaging (MRI) contrast agents. These branched macromolecules were prepared by one-pot reversible addition fragmentation chain transfer (RAFT) polymerization and conjugating chemistry. A biodegradable GFLG oligopeptide was used to successfully link the branch-chains of the branched macromolecules, finally a conjugate of this branched macromolecule and DOTA-Gd (HB-pGAEMA-Gd) with a molecular weight (MW) of 124 kDa was produced. Meanwhile, to improve the ability of tumor-targeting, we conjugated a tumor-targeting cRGDyK cyclic peptide to the branched molecule to prepare a tumor-targeted branched macromoleculeDOTA-Gd conjugate (HB-pGAEMA-RGD-Gd) with a MW of 136 kDa. The prepared branched macromolecules had a nanoscale hydrodynamic particle size and could be degraded into lower MW fragments with the cathepsin B. The aqueous phase relaxation efficiency of HB-pGAEMA-RGD-Gd (12.3 mM–1s–1 and HB-pGAEMA-Gd (13.2 mM–1s–1 was four times higher than that of DTPA-Gd (2.9 mM–1s–1), a clinically used contrast agent. In comparison with DTPA-Gd, the branched macromolecular contrast agents significantly enhanced the MRI signal intensity at the tumor site in vivo, and the enhancement of MRI signal intensity was up to 6 times that of the DTPA-Gd owing to their high relaxation efficiencies and accumulation at the tumor site. In addition, in vitro and in vivo toxicity studies indicated that the degradable macromolecular contrast agents had no significant toxicity.

Preparation of linear poly(glycerol) as a T1 contrast agent for tumor-targeted magnetic resonance imaging

2016 ◽  
Vol 4 (41) ◽  
pp. 6716-6725 ◽  
Author(s):  
Yi Cao ◽  
Min Liu ◽  
Kunchi Zhang ◽  
Jingjin Dong ◽  
Guangyue Zu ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
Small Molecule ◽  
Resonance Imaging ◽  
T1 Contrast Agent ◽  
T1 Contrast ◽  
Linear Poly

Macromolecular contrast agents (CAs) labeled with targeting molecules are gaining remarkable interest as promising materials overcoming the defects of small-molecule CAs.

Multi-arm star-branched polymer as an efficient contrast agent for tumor-targeted magnetic resonance imaging

2017 ◽  
Vol 5 (25) ◽  
pp. 5001-5008 ◽  
Author(s):  
Guangyue Zu ◽  
Ye Kuang ◽  
Jingjin Dong ◽  
Yi Cao ◽  
Kewei Wang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agent ◽  
Contrast Agents ◽  
High Efficiency ◽  
Resonance Imaging ◽  
Branched Polymer ◽  
Imaging Probes

Contrast agents with high efficiency and safety are excellent candidates as magnetic resonance imaging probes.

Supramolecular Enhancement of Aminoxyl ORCA Contrast Agents

2019 ◽  
Author(s):  
Hamilton Lee ◽  
Jenica Lumata ◽  
Michael A. Luzuriaga ◽  
Candace Benjamin ◽  
Olivia Brohlin ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Side Effects ◽  
Magnetic Resonance ◽  
Tobacco Mosaic Virus ◽  
Contrast Agents ◽  
Single Molecule ◽  
Organic Radical ◽  
Resonance Imaging ◽  
Physiological Conditions

<div><div><div><p>Many contrast agents for magnetic resonance imaging are based on gadolinium, however side effects limit their use in some patients. Organic radical contrast agents (ORCAs) are potential alternatives, but are reduced rapidly in physiological conditions and have low relaxivities as single molecule contrast agents. Herein, we use a supramolecular strategy where cucurbit[8]uril binds with nanomolar affinities to ORCAs and protects them against biological reductants to create a stable radical in vivo. We further over came the weak contrast by conjugating this complex on the surface of a self-assembled biomacromolecule derived from the tobacco mosaic virus.</p></div></div></div>

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