Gadonanotubes as magnetic nanolabels for stem cell detection

Stem cell-based therapies have emerged as a promising approach in regenerative medicine In the development of such therapies the demand for imaging technologies that permit the noninvasive monitoring of transplanted stem cells in vivo is growing Here we report the performance of gadolinium-containing carbon nanocapsules or gadonanotubes (GNTs) as a new T-1-weighted magnetic resonance imaging (MRI) intracellular labeling agent for pig bone marrow-derived mesenchymal stem cells (MSCs) Without the use of a transfection agent micromolar concentrations of GNTs can deliver up to 10(9) Gd3+ ions per cell without compromising cell viability differentiation potential proliferation pattern and phenotype Imaging 10 x 10(6) GNT-labeled MSCs demonstrates a nearly two-fold reduction in T-1 relaxation time when compared to unlabeled MSCs at 1 5 T in a clinical MRI scanner which easily permits the discrimination of GNT-labeled MSCs in a T-1-weighted MR image It is anticipated that GNTs will allow in vivo tracking of GNT-labeled MSCs as well as other mammalian cell types by T-1-weighted imaging with greater efficacy than other current technologies now allow (C) 2010 Elsevier Ltd All rights reserved