An update on clinical applications of magnetic nanoparticles for increasing the resolution of magnetic resonance imaging (original) (raw)
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Iron-based magnetic nanoparticles for magnetic resonance imaging
Advanced Powder Technology, 2018
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Applications of magnetic nanoparticles (MNPs) as Magnetic resonance imaging (MRI) contrast agent have been widely developed during recent years. MNPs have some unique featuresthat make them interesting option in biomedical applications. While almost all contrast agents for MRI affect both T1 and T2,the selective effects of MNPs on one of T1 or T2 is usually more prominent, leading to the division of these probes to contrast agents of T1 and T2. Among MNPs, paramagnetic NPs can affect T1relaxivity, called as T1weighted contrast agent, whereas super paramagnetic NPs are known as T2-weighted contrast agent. Due to high cellular adsorption of MNPs, they can provide helpful differences between different cell types. The present study reviews the recent advances in applications of MNPs as contrast agents in MRI and focuses on the clinical applications of these techniques in different diseases.
The Japan Society of Applied Physics, 2017
MRI technique is a well-known noninvasive imaging technique based on Magnetic Resonance. However, it is difficult to apply this technique for tumor imaging. This is because the tumor physical property is mostly identical with the surrounding tissue, therefore it shows the same contrast during MR Imaging. Currently, the gadolinium (Gd) based contrast agent such as Magnevist® is injected into the patience prior the imaging to effectively change the magnetic property (T1 brightening effect) of the tumor cell. Although Gd is effective, it is dangerous for our body as humans do not have a metabolic pathway for Gd. The use of Gd based agents has also been linked to nephrogenic systemic fibrosis (NSF) in patients. It is important that we develop a new generation of benign contrast agents that are competitive with commercial Gd based contrast agents. As previously reported, Mn8Fe4VBA magnetic cluster encapsulated in polymer nanoparticles (NPs) represents a potential candidate as contrast ag...
Magnetic Nanomaterials as Contrast Agents for MRI
Materials, 2020
Magnetic Resonance Imaging (MRI) is a powerful, noninvasive and nondestructive technique, capable of providing three-dimensional (3D) images of living organisms. The use of magnetic contrast agents has allowed clinical researchers and analysts to significantly increase the sensitivity and specificity of MRI, since these agents change the intrinsic properties of the tissues within a living organism, increasing the information present in the images. Advances in nanotechnology and materials science, as well as the research of new magnetic effects, have been the driving forces that are propelling forward the use of magnetic nanostructures as promising alternatives to commercial contrast agents used in MRI. This review discusses the principles associated with the use of contrast agents in MRI, as well as the most recent reports focused on nanostructured contrast agents. The potential applications of gadolinium- (Gd) and manganese- (Mn) based nanomaterials and iron oxide nanoparticles in ...
Magnetic nanoparticles as MRI contrast agents
Science-Business eXchange
Magnetic Resonance Imaging (MRI) is a non-invasive imaging modality that offers both anatomical and functional information. Intrinsic longitudinal and transverse relaxation times (T 1 and T 2 , respectively) provide tools to manipulate image contrast. Additional control is yielded when paramagnetic and magnetic particulate materials are used as contrast materials. Superparamagnetic particles are mostly synthesized from iron oxide and are usually coated with polymers and functional particles to offer multifunctional biomedical applications. The latter include not only MRI but also cancer treatment through drug delivery and hyperthermia. This Chapter reviews the fundamental dipole-dipole diamagnetic proton relaxation mechanism dominant in water followed by a brief description of the use of gadolinium complexes as MRI contrast agent. Finally, a description of the important chemical and physical properties of magnetic nanoparticle (MNP) that define their use as MRI relaxation enhancing agents especially for T 2. The main governing models are described for the different motional regimes with few simulation results demonstrating the applicability of the given equations.
Magnetic Nanoparticles as Contrast Agents for Magnetic Resonance Imaging
Proceedings of the National Academy of Sciences, India. Section A, Physical sciences, 2012
For over twenty years, superparamagnetic nanoparticles have been developed for a number of medical applications ranging from bioseparations, magnetic drug targeting, hyperthermia and imaging. Here we review several imaging technologies developed using functionalized superparamagnetic iron oxide nanoparticles (SPIONs) as targeted molecular agents. Several imaging modalities have exploited the large induced magnetic moment of SPIONs to create local mechanical force. For in vivo applications, magnetomotive modulation of primary images in ultrasound (US), photoacoustics (PA), and optical coherence tomography (OCT) can help identify very small concentrations of nanoagents while simultaneously suppressing intrinsic background signals from tissue.
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Contrast agents, such as iron oxide, enhance MR images by altering the relaxation times of tissues in which the agent is present. They can also be used to label targeted molecular imaging probes. Unfortunately, no molecular imaging probe is currently available on the clinical MRI market. A promising platform for MRI contrast agent development is nanotechnology, where superparamagnetic iron oxide nanoparticles (SPIONS) are tailored for MR contrast enhancement, and/or for molecular imaging. SPIONs can be produced using a range of methods and the choice of method will be influenced by the characteristics most important for a particular application. In addition, the ability to attach molecular markers to SPIONS heralds their application in molecular imaging. There are many reviews on SPION synthesis for MRI; however, these tend to be targeted to a chemistry audience. The development of MRI contrast agents attracts experienced researchers from many fields including some researchers with ...
Metallic Iron Nanoparticles for MRI Contrast Enhancement
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Iranian Journal of Pharmaceutical Research : IJPR, 2019
Nanoparticles are unique that enable many promising medical and technological applications in their physical, and chemical properties. It is widely accepted that nanoparticles should be thoroughly tested for health nanotoxicity, but a moderate risk analysis is currently prevented by a revealing absence of mechanistic knowledge of nanoparticle toxicity. The purpose of this study was to assess in-vitro cytotoxicity of Gadolinium oxide with diethylene glycol polymer (Gd2O3-DEG) and magneto liposome nanoparticles (MLNs) in Hepa 1-6 cell lines as models to assess nanotoxicity in-vitro. The effects of magnetic nanoparticles on these cell lines were evaluated by light microscopy and standard cytotoxicity assays. The underlying interactions of these nanoparticles with physiological fluids are key characteristics of the perception of their biological efficacy, and these interactions can perhaps be performed to relieve unpleasant toxic effects. Our results demonstrated that the Gd2O3-DEG and ...
Magnetic Nanoparticles as Contrast Agents for Medical Diagnosis
Nanotechnology in Biology and Medicine, 2007
For over twenty years, superparamagnetic nanoparticles have been developed for a number of medical applications ranging from bioseparations, magnetic drug targeting, hyperthermia and imaging. Here we review several imaging technologies developed using functionalized superparamagnetic iron oxide nanoparticles (SPIONs) as targeted molecular agents. Several imaging modalities have exploited the large induced magnetic moment of SPIONs to create local mechanical force. For in vivo applications, magnetomotive modulation of primary images in ultrasound (US), photoacoustics (PA), and optical coherence tomography (OCT) can help identify very small concentrations of nanoagents while simultaneously suppressing intrinsic background signals from tissue.