Title
Gadolinium-Encapsulating Iron Oxide Nanoprobe as Activatable NMR/MRI Contrast Agent
Abbreviated Journal Title
ACS Nano
Keywords
activatable MRI imaging; magnetic relaxation; iron oxide nanoprobe; Gd-DTPA complex; theranostic application; MRI; NANOPARTICLES; RELAXATION; T-1; RELAXIVITY; COMPLEX; NANOCOMPOSITES; VISUALIZATION; ENHANCEMENT; SENSITIVITY; Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience &; Nanotechnology; Materials Science, Multidisciplinary
Abstract
Herein we report a novel gadolinium-encapsulating iron oxide nanoparticle-based activatable NMR/MRI nanoprobe. In our design, Gd-DTPA is encapsulated within the poly(acrylic acid) (PAA) polymer coating of a superparamagnetic iron oxide nanoparticle (IO-PAA), yielding a composite magnetic nanoprobe (IO-PAA-Gd-DTPA) with quenched longitudinal spin lattice magnetic relaxation (T-1). Upon release of the Gd-DTPA complex from the nanoprobe's polymeric coating in acidic media, an increase in the T-1 relaxation rate (1/T-1) of the composite magnetic nanoprobe was observed, indicating a dequenching of the nanoprobe with a corresponding increase in the T-1-weighted MRI signal. When a folate-conjugated nanoprobe was incubated In HeLa cells, a cancer cell line overexpressing folate receptors, an increase in the 1/T-1 signal was observed. This result suggests that, upon receptor-mediated internalization, the composite magnetic nanoprobe degraded within the cell's lysosome acidic (pH 5.0) environment, resulting in an intracellular release of Gd-DTPA complex with subsequent T-1 activation. In addition, when an anticancer drug (Taxol) was coencapsulated with the Gd-DTPA within the folate receptor targeting composite magnetic nanoprobe, the T-1 activation of the probe coincided with the rate of drug release and corresponding cytotoxic effect in cell culture studies. Taken together, these results suggest that our activatable T-1 nanoagent could be of great importance for the detection of acidic tumors and assessment of drug targeting and release by MRI.
Journal Title
Acs Nano
Volume
6
Issue/Number
8
Publication Date
1-1-2012
Document Type
Article
DOI Link
Language
English
First Page
7281
Last Page
7294
WOS Identifier
ISSN
1936-0851
Recommended Citation
"Gadolinium-Encapsulating Iron Oxide Nanoprobe as Activatable NMR/MRI Contrast Agent" (2012). Faculty Bibliography 2010s. 3246.
https://stars.library.ucf.edu/facultybib2010/3246
Comments
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