Open Access Nano Express

Highly sensitive magnetite nano clusters for MR cell imaging

Mingli Li, Hongchen Gu and Chunfu Zhang*

Author Affiliations

School of Biomedical Engineering & Med-X Research Institute, Shanghai Jiao Tong University, Shanghai 200030, China

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Nanoscale Research Letters 2012, 7:204  doi:10.1186/1556-276X-7-204

Published: 31 March 2012

Abstract

High sensitivity and suitable sizes are essential for magnetic iron oxide contrast agents for cell imaging. In this study, we have fabricated highly MR sensitive magnetite nanoclusters (MNCs) with tunable sizes. These clusters demonstrate high MR sensitivity. Especially, water suspensions of the MNCs with average size of 63 nm have transverse relaxivity as high as 630 s-1mM-1, which is among the most sensitive iron oxide contrast agents ever reported. Importantly, such MNCs have no adverse effects on cells (RAW 264.7). When used for cell imaging, they demonstrate much higher efficiency and sensitivity than those of SHU555A (Resovist), a commercially available contrast agent, both in vitro and in vivo, with detection limits of 3,000 and 10,000 labeled cells, respectively. The studied MNCs are sensitive for cell imaging and promising for MR cell tracking in clinics.

Keywords:
Magnetic resonance imaging; magnetic nano cluster; cell imaging; polyol method