Blood-Pool MRI Contrast Agents: Properties and Characterization

Clarkson, R. B.

doi:10.1007/3-540-45733-x_7

Cited by 30 publications

(17 citation statements)

References 86 publications

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“…MIONs have been predominantly used as negative contrast agents (R 2 relaxivity) in clinical applications (1), but recently there has been some interest in engineering contrast agents with decreased R 2 /R 1 ratios for use as blood pool agents (25, 26). Although chelated Gd 3+ and Gd 3+ ‐linked albumin have been the dominant blood pool contrast agents approved and used in the clinical setting, they need to be used at high concentrations, have relatively short circulation times, and can have toxic side effects (27). Therefore, the use of MIONs (or other superparamagnetic iron oxide nanoparticles) as blood pool agents has been explored as an alternative (25, 26, 28).…”

Section: Discussionmentioning

confidence: 99%

Coating thickness of magnetic iron oxide nanoparticles affects R₂ relaxivity

LaConte

Nitin

Zurkiya

et al. 2007

Magnetic Resonance Imaging

213

211

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Purpose:To evaluate the effect of coating thickness on the relaxivity of iron oxide nanoparticles. Materials and Methods:Monocrystalline superparamagnetic iron oxide nanoparticles (MIONs), coated with a polyethylene glycol (PEG)-modified, phospholipid micelle coating, with different PEG molecular weights, were prepared. The particle diameters were measured with dynamic light scattering (DLS) and electron microscopy (EM). The R 1 and R 2 of MIONs were measured using a bench-top nuclear magnetic resonance (NMR) relaxometer. pH was varied for some measurements. Monte Carlo simulations of proton movement in a field with nanometer-sized magnetic inhomogeneities were performed. Results:Increasing the molecular weight of the PEG portion of the micelle coating increased overall particle diameter. As coating thickness increases, the R 2 decreases and the R 1 increases. Changing pH has no effect on relaxivity. The Monte Carlo simulations suggest that the effect of coating size on R 2 relaxivity is determined by two competing factors: the physical exclusion of protons from the magnetic field and the residence time for protons within the coating zone. Conclusion:Coating thickness can significantly impact the R 2 , and the R 2 /R 1 ratio, of a MION contrast agent. An understanding of the relationship between coating properties and changes in relaxivity is critical for designing magnetic nanoparticle probes for molecular imaging applications using MRI.

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Section: Discussionmentioning

confidence: 99%

Coating thickness of magnetic iron oxide nanoparticles affects R₂ relaxivity

LaConte

Nitin

Zurkiya

et al. 2007

Magnetic Resonance Imaging

213

211

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“…The presence of paramagnetic ions near water protons shortens their T 1 relaxation time through coordination with water molecules providing increased contrast. While gadolinium chelates are widely used, their short blood circulation times, poor detection sensitivity and toxicity concerns have led to the continued development of SPIONs for T 2 contrast enhancement 15,16 .…”

Section: Mr and Relaxation Properties Of Spionsmentioning

confidence: 99%

Magnetite nanoparticles for medical MR imaging

2011

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Nanotechnology has given scientists new tools for the development of advanced materials for the detection and diagnosis of disease. Iron oxide nanoparticles (SPIONs) in particular have been extensively investigated as novel magnetic resonance imaging (MRI) contrast agents due to a combination of favorable superparamagnetic properties, biodegradability, and surface properties of easy modification for improved in vivo kinetics and multifunctionality. This review discusses the basics of MR imaging, the origin of SPION’s unique magnetic properties, recent developments in MRI acquisition methods for detection of SPIONs, synthesis and post-synthesis processes that improve SPION’s imaging characteristics, and an outlook on the translational potential of SPIONs.

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“…Examples of the different classes of vascular agents along with specific compounds within each class and their mechanism of vascular localization are described below. Unfortunately, due to space restrictions, the authors were not able to include references to a number of research papers and direct interested readers to other reviews [1,26,27].…”

Section: Vascular Agents (Blood Pool Contrast Agents)mentioning

confidence: 99%

Gadolinium Meets Medicinal Chemistry: MRI Contrast Agent Development

Zhang¹,

Nair²,

McMurry³

2005

CMC

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Magnetic resonance imaging (MRI) contrast agents are utilized adjunctively to enhance the contrast between normal and abnormal structures on MRI scans. Along with the rapid evolution of the field has come a new appreciation for the medicinal chemistry of this unique class of metallopharmaceuticals. The efficacy of MRI agents is a complex function of chemical, biophysical, and pharmacological properties, which must be married in a package of exquisite safety. This report illustrates the wide range of medicinal chemistry relevant to existing agents that are either approved or in clinical development, as well as concepts, which may result in exciting new pharmaceuticals in the future.

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Blood-Pool MRI Contrast Agents: Properties and Characterization

Cited by 30 publications

References 86 publications

Coating thickness of magnetic iron oxide nanoparticles affects R₂ relaxivity

Coating thickness of magnetic iron oxide nanoparticles affects R₂ relaxivity

Magnetite nanoparticles for medical MR imaging

Gadolinium Meets Medicinal Chemistry: MRI Contrast Agent Development

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Blood-Pool MRI Contrast Agents: Properties and Characterization

Cited by 30 publications

References 86 publications

Coating thickness of magnetic iron oxide nanoparticles affects R2 relaxivity

Coating thickness of magnetic iron oxide nanoparticles affects R2 relaxivity

Magnetite nanoparticles for medical MR imaging

Gadolinium Meets Medicinal Chemistry: MRI Contrast Agent Development

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Product

Resources

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Coating thickness of magnetic iron oxide nanoparticles affects R₂ relaxivity

Coating thickness of magnetic iron oxide nanoparticles affects R₂ relaxivity