Covalent functionalization of multi-walled carbon nanotubes with a gadolinium chelate for efficient T1-weighted magnetic resonance imaging

Given the promise of carbon nanotubes (CNTs) for photothermal therapy, drug delivery, tissue engineering, and gene therapy, there is a need for non-invasive imaging methods to monitor CNT distribution and fate in the body. In this study, non-ionizing whole-body high field magnetic resonance imaging (MRI) is used to follow the distribution of water-dispersible non-toxic functionalized CNTs administrated intravenously to mice. Oxidized CNTs are endowed with positive MRI contrast properties by covalent functionalization with the chelating ligand diethylenetriaminepentaacetic dianhydride (DTPA), followed by chelation to Gd. The structural and magnetic properties, MR relaxivities, cellular uptake, and application for MRI cell imaging of Gd-CNTs in comparison to the precursor oxidized CNTs are evaluated. Despite the intrinsic T contrast of oxidized CNTs internalized in macrophages, the anchoring of paramagnetic gadolinium onto the nanotube sidewall allows efficient T contrast and MR signal enhancement, which is preserved after CNT internalization by cells. Hence, due to their high dispersibility, Gd-CNTs have the potential to produce positive contrast in vivo following injection into the bloodstream. The uptake of Gd-CNTs in the liver and spleen is assessed using MRI, while rapid renal clearance of extracellular Gd-CNTs is observed, confirming the evidences of other studies using different imaging modalities

コウブンシ ヒフクカ ガンマ - Fe2O3 ナノ ビリュウシ : ゴウセイ オヨビ ブッセイ

京都大学0048新制・課程博士博士(理学)甲第11051号理博第2829号新制||理||1421(附属図書館)22583UT51-2004-J723京都大学大学院理学研究科化学専攻(主査)教授 高野 幹夫, 教授 島川 祐一, 教授 梅村 純三学位規則第4条第1項該当Doctor of ScienceKyoto UniversityDA

Covalent functionalization of multi-walled carbon nanotubes with a gadolinium chelate for efficient T1-weighted magnetic resonance imaging

Given the promise of carbon nanotubes (CNTs) for photothermal therapy, drug delivery, tissue engineering, and gene therapy, there is a need for non-invasive imaging methods to monitor CNT distribution and fate in the body. In this study, non-ionizing whole-body high field magnetic resonance imaging (MRI) is used to follow the distribution of water-dispersible non-toxic functionalized CNTs administrated intravenously to mice. Oxidized CNTs are endowed with positive MRI contrast properties by covalent functionalization with the chelating ligand diethylenetriaminepentaacetic dianhydride (DTPA), followed by chelation to Gd. The structural and magnetic properties, MR relaxivities, cellular uptake, and application for MRI cell imaging of Gd-CNTs in comparison to the precursor oxidized CNTs are evaluated. Despite the intrinsic T contrast of oxidized CNTs internalized in macrophages, the anchoring of paramagnetic gadolinium onto the nanotube sidewall allows efficient T contrast and MR signal enhancement, which is preserved after CNT internalization by cells. Hence, due to their high dispersibility, Gd-CNTs have the potential to produce positive contrast in vivo following injection into the bloodstream. The uptake of Gd-CNTs in the liver and spleen is assessed using MRI, while rapid renal clearance of extracellular Gd-CNTs is observed, confirming the evidences of other studies using different imaging modalities