Functionalization of PAMAM dendrimers with nitronyl nitroxide radicals as models for the outer-sphere relaxation in dentritic potential MRI contrast agents

2003 ◽  
Vol 41 (2) ◽  
pp. 81-83 ◽  
Author(s):  
Giancarlo Francese ◽  
Frank A. Dunand ◽  
Claudia Loosli ◽  
Andr� E. Merbach ◽  
Silvio Decurtins
Keyword(s):  
Contrast Agents ◽  
Outer Sphere ◽  
Pamam Dendrimers ◽  
Mri Contrast Agents ◽  
Nitronyl Nitroxide ◽  
Nitroxide Radicals ◽  
Mri Contrast

In Vivo Evaluation of a PAMAM-Cystamine-(Gd-DO3A) Conjugate as a Biodegradable Macromolecular MRI Contrast Agent

2007 ◽  
Vol 232 (8) ◽  
pp. 1081-1089 ◽  
Author(s):  
Rongzuo Xu ◽  
Yanli Wang ◽  
Xuli Wang ◽  
Eun-Kee Jeong ◽  
Dennis L. Parker ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Contrast Enhancement ◽  
Blood Pool ◽  
Pamam Dendrimers ◽  
Mri Contrast Agents ◽  
The Body ◽  
Mri Contrast Agent ◽  
High Toxicity ◽  
Mri Contrast

Macromolecular Gd(III) chelates are superior magnetic resonance imaging (MRI) contrast agents for blood pool and tumor imaging. However, their clinical development is limited by the safety concerns related to the slow excretion and long-term gadolinium tissue accumulation. A generation 6 PAMAM Gd(III) chelate conjugate with a cleavable disulfide spacer, PAMAM-G6-cystamine-(Gd-DO3A), was prepared as a biodegradable macromolecular MRI contrast agent with rapid excretion from the body. T1 and T2 relaxivities of the contrast agent were 11.6 and 13.3 m M−1sec−1 at 3T, respectively. Blood pool and tumor contrast enhancement of the agent were evaluated in female nude mice bearing MDA-MB-231 human breast carcinoma xenografts with a nondegradable conjugate PAMAM-G6-(Gd-DO3A) as a control. PAMAM-G6-cystamine-(Gd-DO3A) resulted in significant contrast enhancement in the blood for about 5 mins, and Gd-DO3A was released from the conjugate and rapidly excreted via renal filtration after the disulfide spacer was cleaved. The nondegradable control had much longer blood circulation and excreted more slowly from the body. PAMAM-G6-cystamine-(Gd-DO3A) also resulted in more prominent tumor contrast enhancement than the control. However, PAMAM-G6-cystamine-(Gd-DO3A) demonstrated high toxicity due to the intrinsic toxicity of PAMAM dendrimers. In conclusion, although PAMAM-G6-cystamine-(Gd-DO3A) showed some advantages compared with the nondegradable control, PAMAM dendrimers are not suitable carriers for biodegradable macromolecular MRI contrast agents, due to their high toxicity.

Cubosomes as Carriers for MRI Contrast Agents

2017 ◽  
Vol 24 (5) ◽  
pp. 470-482 ◽  
Author(s):  
Nicolas Alcaraz ◽  
Ben J. Boyd
Keyword(s):  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast

Biocompatible dextran-coated gadolinium-doped cerium oxide nanoparticles as MRI contrast agents with high T1 relaxivity and selective cytotoxicity to cancer cells

2021 ◽  
Author(s):  
Anton Popov ◽  
Maxim Artemovich Abakumov ◽  
Irina Savintseva ◽  
Artem Ermakov ◽  
Nelly Popova ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Resonance Imaging ◽  
Mri Contrast ◽  
Selective Cytotoxicity ◽  
Magnetic Resonance Imaging Mri

Gd-based complexes are widely used as magnetic resonance imaging (MRI) contrast agents. The safety of previously approved contrast agents is questionable and is being re-assessed. The main causes of concern...

scholarly journals Correction to: Magnetic Nanoparticles as MRI Contrast Agents

2021 ◽  
Vol 379 (4) ◽  
Author(s):  
Ashish Avasthi ◽  
Carlos Caro ◽  
Esther Pozo-Torres ◽  
Manuel Pernia Leal ◽  
María Luisa García-Martín
Keyword(s):  
Magnetic Nanoparticles ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast

A correction to this paper has been published: https://doi.org/10.1007/s41061-021-00340-y

One-Step Synthesis of Single-Stranded DNA-Bridged Iron Oxide Supraparticles as MRI Contrast Agents

Nano Letters ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2793-2799
Author(s):  
Jingfang Zhang ◽  
Zhenghan Di ◽  
Husheng Yan ◽  
Yuliang Zhao ◽  
Lele Li
Keyword(s):  
Iron Oxide ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Single Stranded Dna ◽  
Mri Contrast ◽  
One Step

scholarly journals Study on Establishing Reference Safe Concentrations of MRI Contrast Agents for Optimized Images: Paramagnetic Gd-DTPA-BMEA and Superparamagnetic Ferucarbotran

2021 ◽  
Vol 11 (3) ◽  
pp. 1165
Author(s):  
Wen-Tien Hsiao ◽  
Yi-Hong Chou ◽  
Jhong-Wei Tu ◽  
Ai-Yih Wang ◽  
Lu-Han Lai
Keyword(s):  
Contrast Agent ◽  
Contrast Agents ◽  
Mri Contrast Agents ◽  
Mri Contrast Agent ◽  
In Vitro Experiments ◽  
Mri Contrast ◽  
In Vivo Experiments ◽  
Contrast Agent Injection

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.

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