Browsing by Author "Qu, Feifei"

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    Enhanced MRI relaxivity of aquated Gd3+ﾠions by carboxyphenylated water-dispersed graphene nanoribbons
    (Royal Society of Chemistry, 2014) Gizzatov, Ayrat; Keshishian, Vazrik; Guven, Adem; Dimiev, Ayrat M.; Qu, Feifei; Muthupillai, Raja; Decuzzi, Paolo; Bryant, Robert G.; Tour, James M.; Wilson, Lon J.; Richard E. Smalley Institute for Nanoscale Science and Technology
    The present study demonstrates that highly water-dispersed graphene nanoribbons dispersed by carboxyphenylated substituents and conjugated to aquated Gd3+ﾠions can serve as a high-performance contrast agent (CA) for applications inﾠT1- andﾠT2-weighted magnetic resonance imaging (MRI) with relaxivity (r1,2) values outperforming currently-available clinical CAs by up to 16 times forﾠr1ﾠand 21 times forﾠr2.
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    Surfactant-free Gd3+-ion-containing carbon nanotube MRI contrast agents for stem cell labeling
    (Royal Society of Chemistry, 2015) Gizzatov, Ayrat; Hernández-Rivera, Mayra; Keshishian, Vazrik; Mackeyev, Yuri; Law, Justin J.; Guven, Adem; Sethi, Richa; Qu, Feifei; Muthupillai, Raja; Cabreira-Hansen, Maria da Graça; Willerson, James T.; Perin, Emerson C.; Ma, Qing; Bryant, Robert G.; Wilson, Lon J.; Richard E. Smalley Institute for Nanoscale Science and Technology
    There is an ever increasing interest in developing new stem cell therapies. However, imaging and tracking stem cells in vivo after transplantation remains a serious challenge. In this work, we report new, functionalized and high-performance Gd3+-ion-containing ultra-short carbon nanotube (US-tube) MRI contrast agent (CA) materials which are highly-water-dispersible (ca. 35 mg ml−1) without the need of a surfactant. The new materials have extremely high T1-weighted relaxivities of 90 (mM s)−1 per Gd3+ ion at 1.5 T at room temperature and have been used to safely label porcine bone-marrow-derived mesenchymal stem cells for MR imaging. The labeled cells display excellent image contrast in phantom imaging experiments, and TEM images of the labeled cells, in general, reveal small clusters of the CA material located within the cytoplasm with 109 Gd3+ ions per cell.