scholarly journals Polyphosphorhydrazone-Based Radical Dendrimers

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1230
Author(s):  
Vega Lloveras ◽  
José Vidal-Gancedo
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Biomedical Applications ◽  
Organic Radicals ◽  
Resonance Imaging ◽  
Metal Free ◽  
Antioxidant Agents ◽  
New Type ◽  
Paramagnetic Properties

The search for new biomedical applications of dendrimers has promoted the synthesis of new radical-based molecules. Specifically, obtaining radical dendrimers has opened the door to their use in various fields such as magnetic resonance imaging, as anti-tumor or antioxidant agents, or the possibility of developing new types of devices based on the paramagnetic properties of organic radicals. Herein, we present a mini review of radical dendrimers based on polyphosphorhydrazone, a new type of macromolecule with which, thanks to their versatility, new metal-free contrast agents are being obtained, among other possible applications.

scholarly journals Assessment of the Relaxation-Enhancing Properties of a Nitroxide-Based Contrast Agent TEEPO-Glc with In Vivo Magnetic Resonance Imaging

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Maiju Soikkeli ◽  
Mikko I. Kettunen ◽  
Riikka Nivajärvi ◽  
Venla Olsson ◽  
Seppo Rönkkö ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Tumor Targeting ◽  
Water Soluble ◽  
Organic Radicals ◽  
Resonance Imaging ◽  
Metal Free ◽  
Stable Nitroxide

Magnetic resonance imaging examinations are frequently carried out using contrast agents to improve the image quality. Practically all clinically used contrast agents are based on paramagnetic metals and lack in selectivity and specificity. A group of stable organic radicals, nitroxides, has raised interest as new metal-free contrast agents for MRI. Their structures can easily be modified to incorporate different functionalities. In the present study, a stable nitroxide TEEPO (2,2,6,6-tetraethylpiperidin-1-oxyl) was linked to a glucose moiety (Glc) to construct a water-soluble, potentially tumor-targeting compound with contrast-enhancing ability. The ability was assessed with in vivo MRI experiments. The constructed TEEPO-Glc agent proved to shorten the T1 relaxation time in tumor, while the T1 time in healthy brain tissue remained the same. The results indicate the potential of TEEPO-Glc as a valuable addition to the growing field of metal-free contrast enhancement in MRI-based diagnostics.

Silica-coated super-paramagnetic iron oxide nanoparticles (SPIONPs): a new type contrast agent of T1 magnetic resonance imaging (MRI)

2015 ◽  
Vol 3 (26) ◽  
pp. 5172-5181 ◽  
Author(s):  
M. Zubair Iqbal ◽  
Xuehua Ma ◽  
Tianxiang Chen ◽  
Ling'e Zhang ◽  
Wenzhi Ren ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Iron Oxide ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Oxide Nanoparticles ◽  
Resonance Imaging ◽  
Mri Contrast ◽  
New Type ◽  
Magnetic Resonance Imaging Mri

Silica-coated-SPIONPs-T1 enhanced MRI contrast agents.

Supramolecular and Biomacromolecular Enhancement of Metal-Free Magnetic Resonance Imaging Contrast Agents

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

<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>

Supramolecular and Biomacromolecular Enhancement of Metal-Free Magnetic Resonance Imaging Contrast Agents

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

<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>

scholarly journals Supramolecular and biomacromolecular enhancement of metal-free magnetic resonance imaging contrast agents

2020 ◽  
Vol 11 (8) ◽  
pp. 2045-2050 ◽  
Author(s):  
Hamilton Lee ◽  
Arezoo Shahrivarkevishahi ◽  
Jenica L. Lumata ◽  
Michael A. Luzuriaga ◽  
Laurel M. Hagge ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Organic Radical ◽  
Resonance Imaging ◽  
Nitroxide Radicals ◽  
Metal Free ◽  
Magnetic Resonance Imaging Contrast ◽  
Poor Stability

Supramolecular/macromolecular organic radical contrast agents (smORCAs) overcome many of the limitations of nitroxide radicals for use in magnetic resonance imaging in vivo like poor stability and weak contrast.

The Transition from Metal-Based to Metal-Free Contrast Agents for T1 Magnetic Resonance Imaging Enhancement

2019 ◽  
Vol 30 (9) ◽  
pp. 2264-2286 ◽  
Author(s):  
Ozioma Udochukwu Akakuru ◽  
M. Zubair Iqbal ◽  
Madiha Saeed ◽  
Chuang Liu ◽  
Tatjana Paunesku ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Resonance Imaging ◽  
Metal Free

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>

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.

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