Magnetic resonance for<i>in vitro</i>medical diagnostics: superparamagnetic nanoparticle-based magnetic relaxation switches

Demas, Vasiliki; Lowery, Thomas J.

doi:10.1088/1367-2630/13/2/025005

Cited by 28 publications

(37 citation statements)

References 106 publications

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“…(20 -22) Following this work were a series of reports that produced comprehensive numerical models for the dependence of R 2 on superparamagnetic particle size. (23,24) These were extended to modeling particle clusters by the (25) and formed the basis of early explanations of T 2 relaxation time increases and decreases upon analyte-induced clustering, such as the first theoretical discussion of MRSw by Shapiro et al (26) Recently, the authors of this article suggested that these theoretical models could be extended to all MRSw assays (10) to produce practical guidelines and criteria for T2MR assay development. The results from more recent numerical modeling studies have substantiated this hypothesis.…”

Section: Recent Developments In the Magnetic Relaxation Switch Theorymentioning

confidence: 99%

“…(2,10) In T2MR, magnetic resonance signals arise from the nuclei of water hydrogen atoms. Nuclei have an inherent property known as spin which can be thought of as a magnetic moment vector.…”

Section: Fundamentals Of T 2 Relaxationmentioning

confidence: 99%

“…The magnetization and magnetic susceptibility of SPIOs exceed those of naturally occurring paramagnetic substances, such as heme in blood, so background signal from biological samples is negligible. (2,10) SPIOs consist of single or multiple crystals, or cores, <20 nm in diameter, made of a mixture of magnetite (Fe 3 O 4 ) and maghemite (γ-Fe 2 O 3 ), materials with similar magnetic properties. In biosensing applications, these particles are coated with hydrophilic polymers to provide water solubility, biocompatibility, and chemical cross-linking functionality.…”

Section: Nanomaterials For T2mr Sensingmentioning

confidence: 99%

“…This facilitates reagent preparation by providing an easy method for washing and buffer exchange. (2,10) SPIOs smaller than 60 nm are known as ultrasmall SPIOs (USSPIOs). The Brownian motion of USSPIOs keeps them in solution, and they do not separate from solution in the presence of a magnetic field.…”

Section: Nanomaterials For T2mr Sensingmentioning

confidence: 99%

“…The introduction of amines to the surface provides a chemical functional group used to target the particles to biological systems. (2,10) A number of biosensing assay architectures have been built around amine-CLIOs, as summarized in previous reviews, (2,12) including primary antibody labeling of cellular biomarkers, nucleic acid hybridization to target DNA, and small molecule detection. However, improvements in magnetic nanosensors and assay design have optimized this technology beyond that achievable with CLIOs by using novel magnetic particles, which are summarized in this article.…”

Section: Nanomaterials For T2mr Sensingmentioning

confidence: 99%

See 4 more Smart Citations

Nuclear Magnetic Resonance Nanotechnology: Applications in Clinical Diagnostics and Monitoring

Skewis

Demas

Lowery

2013

Encyclopedia of Analytical Chemistry

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Significant progress has been made over the last two decades toward the development of cutting edge diagnostics using magnetic nanoparticles (MNPs) and T 2 magnetic resonance (T2MR). The MNP‐based assay design, termed magnetic relaxation switch (MRSw) biosensing, has allowed for the application of T2MR to a wide range of clinical diagnostics. In MRSw assays, superparamagnetic nanoparticles (NPs) switch between dispersed and agglomerated states and affect the T2MR relaxation rate of surrounding water molecules. Sensitive T2MR relaxation measurements can be performed in complex, heterogeneous, biological samples owing to their inherently low magnetic background. MRSw assays have been designed for rapid and sensitive detection of disease biomarkers, pathogens, and cancer cells in both simulated samples and clinical studies.

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Section: Recent Developments In the Magnetic Relaxation Switch Theorymentioning

confidence: 99%

Section: Fundamentals Of T 2 Relaxationmentioning

confidence: 99%

Section: Nanomaterials For T2mr Sensingmentioning

confidence: 99%

Section: Nanomaterials For T2mr Sensingmentioning

confidence: 99%

Section: Nanomaterials For T2mr Sensingmentioning

confidence: 99%

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Nuclear Magnetic Resonance Nanotechnology: Applications in Clinical Diagnostics and Monitoring

Skewis

Demas

Lowery

2013

Encyclopedia of Analytical Chemistry

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Nuclear Magnetic Resonance Nanotechnology: Applications in Clinical Diagnostics and Monitoring

Snyder

Skewis

Demas

et al. 2019

Encyclopedia of Analytical Chemistry

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Toward absolute quantification of iron oxide nanoparticles as well as cell internalized fraction using multiparametric MRI

Girard

Ramirez

McCarty

et al. 2012

Contrast Media & Molecular

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Iron oxide nanoparticles (IONPs) are widely used as MR contrast agents because of their strong magnetic properties and broad range of applications. The contrast induced by IONPs typically depends on concentration, water accessibility, particle size, and heterogeneity of IONP distribution within the microenvironment. Although the latter could be a tool to assess local physiological effects at the molecular level, it renders IONP quantification from relaxation measurements challenging. This study aims to quantify IONP concentration using susceptibility measurements. In addition, further analysis of relaxation data is proposed to extract quantitative information about the IONP spatial distribution. Mesenchymal stem cells were labeled with IONPs and the IONP concentration measured by mass spectroscopy. MR relaxation parameters (T1, T2, T2*) as well as magnetic susceptibility of cylindrical samples containing serial dilutions of mixtures of free and cell-internalized IONPs were measured and correlated with IONP concentration. Unlike relaxation data, magnetic susceptibility was independent of whether IONPs were free or internalized, making it an excellent candidate for IONP quantification. Using IONP concentration derived from mass spectroscopy and measured relaxation times, free and internalized IONP fractions were accurately calculated. Magnetic susceptibility was shown to be a robust technique to measure IONP concentration in this preliminary study. Novel imaging based susceptibility mapping techniques could prove to be valuable tools to quantify IONP concentration directly by MRI, for samples of arbitrarily shape. Combined with relaxation time mapping techniques, especially T2 and T2*, this could be an efficient way to measure both IONP concentration and the internalized IONP fraction in vivo using MRI, to gain insight into tissue function and molecular imaging paradigms.

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Magnetic resonance forin vitromedical diagnostics: superparamagnetic nanoparticle-based magnetic relaxation switches

Cited by 28 publications

References 106 publications

Nuclear Magnetic Resonance Nanotechnology: Applications in Clinical Diagnostics and Monitoring

Nuclear Magnetic Resonance Nanotechnology: Applications in Clinical Diagnostics and Monitoring

Nuclear Magnetic Resonance Nanotechnology: Applications in Clinical Diagnostics and Monitoring

Toward absolute quantification of iron oxide nanoparticles as well as cell internalized fraction using multiparametric MRI

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