Manganese‐enhanced MRI of rat brain based on slow cerebral delivery of manganese(II) with silica‐encapsulated MnxFe1–xO nanoparticles. (22nd March 2013)

• Record Type: Journal Article
• Authors: Chen, Wei; Lu, Fang; Chen, Chiao‐Chi V.; Mo, Kuan‐Chi; Hung, Yann; Guo, Zhi‐Xuan; Lin, Chia‐Hui; Lin, Ming‐Huang; Lin, Yu‐Hsuan; Chang, Chen; Mou, Chung‐Yuan
• Is Part Of: NMR in biomedicine. Volume 26:Number 9(2013:Sep.)
• Page Start: 1176
• Page End: 1185
• Publication Date: 2013-03-22
• Subjects: Nuclear magnetic resonance -- Periodicals; Magnetic Resonance Spectroscopy -- Periodicals; 574
• DOI: 10.1002/nbm.2932
• Languages: English
• ISSNs: 0952-3480

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>In this work, we report a monodisperse bifunctional nanoparticle system, MIO@SiO<sub>2</sub>‐RITC, as an MRI contrast agent [core, manganese iron oxide (MIO); shell, amorphous silica conjugated with rhodamine B isothiocyanate (RITC)]. It was prepared by thermal decomposition and modified microemulsion methods. The nanoparticles with varying iron to manganese ratios displayed different saturated magnetizations and relaxivities. <italic>In vivo</italic> MRI of rats injected intravenously with MIO@SiO<sub>2</sub>‐RITC nanoparticles exhibited enhancement of the <italic>T</italic><sub>1</sub> contrast in brain tissue, in particular a time‐delayed enhancement in the hippocampus, pituitary gland, striatum and cerebellum. This is attributable to the gradual degradation of MIO@SiO<sub>2</sub>‐RITC nanoparticles in the liver, resulting in the slow release of manganese(II) [Mn(II)] into the blood pool and, subsequently, accumulation in the brain tissue. Thus, <italic>T</italic><sub>1</sub>‐weighted contrast enhancement was clearly detected in the anatomic structure of the brain as time progressed. In addition, <italic>T</italic><sub>2</sub>*‐weighted images of the liver showed a gradual darkening effect. Here, we demonstrate the concept of the slow release of Mn(II) for neuroimaging. This new nanoparticle‐based manganese contrast agent allows one simple intravenous injection (rather than multiple infusions) of Mn(II) precursor, and results in delineation of the detailed anatomic neuroarchitecture in MRI; hence, this provides the advantage of the long‐term study of neural function. Copyright © 2013 John Wiley & Sons, Ltd.</p> </abstract>