Stem cells attached to bio-compatible nanoparticles can be visualized by MRI after transplantation into spinal cord slices. |
Neural
stem cells are a promising treatment for repairing spinal cord injuries
as they have the ability to generate tissue, but there is no effective
way of monitoring the cells for long periods of time after
transplantation.
Nguyen
TK Thanh at the Davy Faraday Research Laboratory, UCL Physics and
Astronomy and the Royal Institution, and colleagues, believe they have
the answer. They have developed hollow biocompatible cobalt-platinum
nanoparticles and attached them to the stem cells. The nanoparticles are
stable for months and have a high magnetic moment – tendency to align
with a magnetic field – so that low concentrations can be detected using
magnetic resonance imaging (MRI).
“Magnetic
nanoparticles are emerging as novel contrast and tracking agents in
medical imaging,” says Samir Pal at the California Institute of
Technology, U.S., an expert in biological-nanoparticle interactions.
“When used as a contrast agent for MRI, the nanoparticles allow
researchers and clinicians to enhance the tissue contrast of an area of
interest by increasing the relaxation rate of water.”
The
team labelled stem cells with their nanoparticles, injected them into
spinal cord slices and took images of their progress over time. They
found that low numbers of the nanoparticle-loaded stem cells could still
be detected two weeks after transplantation.
“The new method demonstrates the feasibility of reliable, noninvasive MRI imaging of nanoparticle-labelled cells,” says Thanh.
Thanh
hopes that her stem cell tracking method will be used during stem cell
replacement therapy for many central nervous system diseases. Her team
is working towards developing nanoparticles that can be used to diagnose
and treat these diseases.
