scholarly journals Neuron labeling with rhodamine-conjugated Gd-based MRI contrast agents delivered to the brain via focused ultrasound

Theranostics ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 2659-2674 ◽  
Author(s):  
Sophie V. Morse ◽  
Tamara Boltersdorf ◽  
Bethany I. Harriss ◽  
Tiffany G. Chan ◽  
Nicoleta Baxan ◽  
...  
Keyword(s):  
Contrast Agents ◽  
Focused Ultrasound ◽  
Mri Contrast Agents ◽  
Mri Contrast ◽  
The Brain

scholarly journals Non-invasive molecularly-specific millimeter-resolution manipulation of brain circuits by ultrasound-mediated aggregation and uncaging of drug carriers

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Mehmet S. Ozdas ◽  
Aagam S. Shah ◽  
Paul M. Johnson ◽  
Nisheet Patel ◽  
Markus Marks ◽  
...  
Keyword(s):  
Focused Ultrasound ◽  
Drug Carriers ◽  
Mri Contrast Agents ◽  
Mri Contrast ◽  
Systemic Injection ◽  
Non Invasive ◽  
Brain Circuits ◽  
Cavitation Detection ◽  
The Brain ◽  
Target Effects

Abstract Non-invasive, molecularly-specific, focal modulation of brain circuits with low off-target effects can lead to breakthroughs in treatments of brain disorders. We systemically inject engineered ultrasound-controllable drug carriers and subsequently apply a novel two-component Aggregation and Uncaging Focused Ultrasound Sequence (AU-FUS) at the desired targets inside the brain. The first sequence aggregates drug carriers with millimeter-precision by orders of magnitude. The second sequence uncages the carrier’s cargo locally to achieve high target specificity without compromising the blood-brain barrier (BBB). Upon release from the carriers, drugs locally cross the intact BBB. We show circuit-specific manipulation of sensory signaling in motor cortex in rats by locally concentrating and releasing a GABAA receptor agonist from ultrasound-controlled carriers. Our approach uses orders of magnitude (1300x) less drug than is otherwise required by systemic injection and requires very low ultrasound pressures (20-fold below FDA safety limits for diagnostic imaging). We show that the BBB remains intact using passive cavitation detection (PCD), MRI-contrast agents and, importantly, also by sensitive fluorescent dye extravasation and immunohistochemistry.

Single-nanometer iron oxide nanoparticles as tissue-permeable MRI contrast agents

2021 ◽  
Vol 118 (42) ◽  
pp. e2102340118
Author(s):  
He Wei ◽  
Agata Wiśniowska ◽  
Jingxuan Fan ◽  
Peter Harvey ◽  
Yuanyuan Li ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Contrast Agents ◽  
Brain Parenchyma ◽  
Mri Contrast Agents ◽  
Imaging Agents ◽  
Mri Contrast ◽  
Blood Brain Barrier Disruption ◽  
Brain Barrier Disruption ◽  
The Brain ◽  
Superparamagnetic Properties

Magnetic nanoparticles are robust contrast agents for MRI and often produce particularly strong signal changes per particle. Leveraging these effects to probe cellular- and molecular-level phenomena in tissue can, however, be hindered by the large sizes of typical nanoparticle contrast agents. To address this limitation, we introduce single-nanometer iron oxide (SNIO) particles that exhibit superparamagnetic properties in conjunction with hydrodynamic diameters comparable to small, highly diffusible imaging agents. These particles efficiently brighten the signal in T1-weighted MRI, producing per-molecule longitudinal relaxation enhancements over 10 times greater than conventional gadolinium-based contrast agents. We show that SNIOs permeate biological tissue effectively following injection into brain parenchyma or cerebrospinal fluid. We also demonstrate that SNIOs readily enter the brain following ultrasound-induced blood–brain barrier disruption, emulating the performance of a gadolinium agent and providing a basis for future biomedical applications. These results thus demonstrate a platform for MRI probe development that combines advantages of small-molecule imaging agents with the potency of nanoscale materials.

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 ◽  
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