Vascular‐targeted molecular imaging using functionalized polymerized vesicles

Li, King C.; Bednarski, Mark D.

doi:10.1002/jmri.10174

Cited by 38 publications

(34 citation statements)

References 15 publications

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“…The use of surface-functionalized nanoparticles provides an alternative means of increasing the sensitivity of detection, particularly in the case of molecular MRI contrast agents. A whole range of nanoparticles have been used including polymerized vesicles (from derivatised polymerizable lipids; Li & Bednarski 2002;Wickline & Lanza 2002), caged magnetic nanoparticles (Schellenberger et al 2004), nanoparticulate emulsions (Winter et al 2003). The functional groups attached were aimed at targeting biochemical epitopes (e.g.…”

Section: Targeting and Sensingmentioning

confidence: 99%

Molecular imaging perspectives

Cassidy

Radda

2005

J. R. Soc. Interface.

138

131

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Molecular imaging is an emerging technology at the life science/physical science interface which is set to revolutionize our understanding and treatment of disease. The tools of molecular imaging are the imaging modalities and their corresponding contrast agents. These facilitate interaction with a biological target at a molecular level in a number of ways. The diverse nature of molecular imaging requires knowledge from both the life and physical sciences for its successful development and implementation. The aim of this review is to introduce the subject of molecular imaging from both life science and physical science perspectives. However, we will restrict our coverage to the prominent in vivo molecular imaging modalities of magnetic resonance imaging, optical imaging and nuclear imaging. The physical basis of these imaging modalities, the use of contrast agents and the imaging parameters of sensitivity, temporal resolution and spatial resolution are described. Then, the specificity of contrast agents for targeting and sensing molecular events, and some applications of molecular imaging in biology and medicine are given. Finally, the diverse nature of molecular imaging and its reliance on interdisciplinary collaboration is discussed.

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Section: Targeting and Sensingmentioning

confidence: 99%

Molecular imaging perspectives

Cassidy

Radda

2005

J. R. Soc. Interface.

138

131

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“…These nanometer-sized particles have a large effect on MRI signal intensities due to the fact that they are superparamagnetic and disrupt magnetic field homogeneity to an extent much larger than their size. A growing number of studies have demonstrated the usefulness of USPIOs and MRI to detect receptors (3,(5)(6)(7)(8) and monitor cell migration (9)(10)(11). Indeed, when a cell is labeled with millions of USPIOs, single cells can be detected by MRI even though the MRI is acquired at low resolution (50-100 m) compared with the size of the cells (5-20 m; refs.…”

mentioning

confidence: 99%

MRI detection of single particles for cellular imaging

Shapiro

Skrtic

Sharer

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

470

414

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There is rapid growth in the use of MRI for molecular and cellular imaging. Much of this work relies on the high relaxivity of nanometer-sized, ultrasmall dextran-coated iron oxide particles. Typically, millions of dextran-coated ultrasmall iron oxide particles must be loaded into cells for efficient detection. Here we show that single, micrometer-sized iron oxide particles (MPIOs) can be detected by MRI in vitro in agarose samples, in cultured cells, and in mouse embryos. Experiments studying effects of MRI resolution and particle size from 0.76 to 1.63 m indicated that T 2 * effects can be readily detected from single MPIOs at 50-m resolution and significant signal effects could be detected at resolutions as low as 200 m. Cultured cells were labeled with fluorescent MPIOs such that single particles were present in individual cells. These single particles in single cells could be detected both by MRI and fluorescence microscopy. Finally, single particles injected into singlecell-stage mouse embryos could be detected at embryonic day 11.5, demonstrating that even after many cell divisions, daughter cells still carry individual particles. These results demonstrate that MRI can detect single particles and indicate that single-particle detection will be useful for cellular imaging.N umerous recent studies (1-4) indicate that there is a wide range of applications for MRI in molecular and cellular imaging. A key requirement for these applications is the availability of high-relaxivity MRI contrast agents that have a large effect on the MRI signal. One of the agents with very high relaxivity is nanometer-sized, ultrasmall dextran-coated iron oxide particles (USPIOs). These nanometer-sized particles have a large effect on MRI signal intensities due to the fact that they are superparamagnetic and disrupt magnetic field homogeneity to an extent much larger than their size. A growing number of studies have demonstrated the usefulness of USPIOs and MRI to detect receptors (3, 5-8) and monitor cell migration (9-11). Indeed, when a cell is labeled with millions of USPIOs, single cells can be detected by MRI even though the MRI is acquired at low resolution (50-100 m) compared with the size of the cells (5-20 m; refs. 12-14).A drawback of techniques that use USPIOs is that for significant signal changes, many particles need to be within an imaging voxel. Recently, we have shown that micrometer-sized iron oxide particles (MPIOs), which are commercially available, are efficiently endocytosed by a variety of cells, and these particles can be used for cellular imaging by MRI (14). Because these particles are polymer-coated and are impregnated with a fluorescent agent, it becomes possible to do both fluorescence microscopy and MRI on cells labeled with such particles. Empirical observations suggest that an iron oxide particle disrupts the magnetic field enough for MRI detectability for a distance at least 50 times its size, ¶ leading to the conclusion that cells harboring single, micrometer-sized particles should be detectable by ...

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“…gadolinium). Since the magnitude of the relaxation by a single paramagnetic label is generally too small, functionalized polymerized vesicles or nanoparticles are additionally needed to attach more than one label in each molecular imaging probe [8]. In US, sensing is accomplished through conjugation of disease-specific ligands for the targeted molecule to a microbubble surface or other acoustically active nanoparticles.…”

Section: Imaging Probesmentioning

confidence: 99%

Fundamentals in Cardiovascular Imaging Technologies

Landini¹,

Santarelli²,

A.V.Jr.³

et al. 2008

CPD

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The aim of this paper is to introduce the prominent in vivo cardiovascular imaging modalities such as magnetic resonance imaging, nuclear imaging and ultrasound from both the physical and molecular imaging perspectives. A brief introduction to the molecular imaging principles is also reported. Special emphasis will be given to the imaging parameters of sensitivity and spatial resolution, and the trade-off between spatial resolution, image contrast and target size.

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Vascular‐targeted molecular imaging using functionalized polymerized vesicles

Cited by 38 publications

References 15 publications

Molecular imaging perspectives

Molecular imaging perspectives

MRI detection of single particles for cellular imaging

Fundamentals in Cardiovascular Imaging Technologies

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