A New High-Performance Gadonanotube-Polymer Hybrid Material for Stem Cell Labeling and Tracking by MRI

Abstract

A gentle, rapid method has been developed to introduce a polyacrylic acid (PAA) polymer coating on the surface of gadonanotubes (GNTs) which significantly increases their dispersibility in water without the need of a surfactant. As a result, the polymer, with its many carboxylic acid groups, coats the surface of the GNTs to form a new GNT-polymer hybrid material (PAA-GNT) which can be highly dispersed in water (ca. 20 mg·mL−1) at physiological pH. When dispersed in water, the new PAA-GNT material is a powerful MRI contrast agent with an extremely short water proton spin-lattice relaxation time (T 1) which results in a T 1-weighted relaxivity of 150 mM−1·s−1 per Gd3+ ion at 1.5 T. Furthermore, the PAA-GNTs have been used to safely label porcine bone-marrow-derived mesenchymal stem cells for magnetic resonance imaging. The labeled cells display excellent image contrast in phantom imaging experiments, and transmission electron microscopy images of the labeled cells reveal the presence of highly dispersed PAA-GNTs within the cytoplasm with 1014 Gd3+ ions per cell.

Theranostic applications of multifunctional carbon nanomaterials

“…This nanoplatform system can be used in labeling cells for MRI and phantom imaging experiments. 53 Modification of CNTs with metals is another strategy to improve their efficiency as MRI agents. Iron-containing MWCNTs are bifunctional nanoparticles capable of being localized in tumor sites by MRI, and to reduce iron toxicity, they can be entrapped within the MWCNT rather than placed on the surface.…”

“…Gadonanotubes are new nanohybrid tools for isolating Gd 3+ ions by encapsulating them within (or upon) ultrashort carbon nanotube capsules, which can increase their dispersibility in water. This nanoplatform system can be used in labeling cells for MRI and phantom imaging experiments 53 . Modification of CNTs with metals is another strategy to improve their efficiency as MRI agents.…”

Multifunctional carbon nanomaterials for diagnostic applications in infectious diseases and tumors

“…5 d). Moghaddam et al employed polyacrylic acid (PAA) to improve the dispersion of Gd 3+ -CNTs in water and successfully performed MRI on porcine bone-marrow-derived mesenchymal stem cells ( r 1 = 150 mM −1 s −1 ) [ 142 ]. This hybrid material also has high intracellular dispersion, containing 10 14 Gd 3+ ions per cell.…”

The leading edge: Emerging neuroprotective and neuroregenerative cell-based therapies for spinal cord injury

“…These are in early deployment such as Neuro‐Spinal Scaffold (NCT02138110) by InVivo Therapeutics Inc or the phase I/II study of MSCs and NSCs using the NeuroRegen scaffold (NCT02688049). Assessing grafted cells in vivo may also become viable as novel MRI‐based cell trackers are developed 213,214 …”