Abstract:
:Dual labeled liposomes, carrying both paramagnetic and fluorescent lipids, were recently proposed as potent contrast agents for MR molecular imaging. These nanoparticles are coated with poly(ethylene glycol) (PEG) to increase their blood circulation half-life, which should allow extensive accumulation at the targeted site. To eliminate nonspecific blood pool signal from the MR images, the circulating liposomes should ideally be cleared from the circulation when sufficient target-specific contrast enhancement is obtained. To that aim, we designed an avidin chase that allowed controlled and rapid clearance of paramagnetic biotinylated liposomes from the blood circulation in C57BL/6 mice. Avidin-induced alterations in blood clearance kinetics and tissue distribution were studied quantitatively by determination of the Gd content in blood and tissue samples ex vivo. Intrinsic liposomal blood clearance showed bi-exponential behavior with half-lives t(1/2alpha) = 2.1 +/- 1.1 and t(1/2beta) = 15.1 +/- 5.4 hours, respectively. In contrast, the contrast agent was cleared from the blood by the avidin infusion to <1% of the initial dose within 4 hours. Avidin-induced liposomal blood clearance was also demonstrated in vivo by dynamic T(1)-weighted MRI. The ability to rapidly clear circulating contrast agents opens up exciting possibilities to study targeting kinetics, to increase the specificity of molecular MRI and to optimize nanoparticulate contrast agent formulations.
journal_name
Magn Reson Medjournal_title
Magnetic resonance in medicineauthors
van Tilborg GA,Strijkers GJ,Pouget EM,Reutelingsperger CP,Sommerdijk NA,Nicolay K,Mulder WJdoi
10.1002/mrm.21780subject
Has Abstractpub_date
2008-12-01 00:00:00pages
1444-56issue
6eissn
0740-3194issn
1522-2594journal_volume
60pub_type
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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更新日期:2001-03-01 00:00:00
abstract:PURPOSE:Previous studies have associated low pH in intervertebral discs (IVDs) with discogenic back pain. The purpose of this study was to determine whether quantitative CEST (qCEST) MRI can be used to detect pH changes in IVDs in vivo. METHODS:The exchange rate ksw between glycosaminoglycan (GAG) protons and water pr...
journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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更新日期:2014-12-01 00:00:00
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journal_title:Magnetic resonance in medicine
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更新日期:2015-08-01 00:00:00
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更新日期:2016-05-01 00:00:00
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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journal_title:Magnetic resonance in medicine
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更新日期:1997-04-01 00:00:00
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