'Magnetic' stem cells target damaged blood vessels
Scientists have harnessed the power of magnetism to guide stem cells towards damaged tissue in rats.
The team coated stem cells with iron nanoparticles. This allowed them to be moved by an external magnet around the body, to the site of injury. It also allowed their path to be tracked using MRI (magnetic resonance imaging) scanners. They used endothelial progenitor stem cells, which circulate in the blood and are involved in the healing of blood vessels. They become endothelial cells, the cells that line the blood vessels.
To test the stem cells, they used rats with vascular injury, where the endothelial cells that line the carotid artery had been stripped away. They then injected the tagged stem cells into the bloodstream. The group of rats exposed to a magnetic field showed a five-fold increase in the number of tagged cells at the site of injury after 24 hours.
Iron nanoparticles have already been approved for medical use in the USA, so human trials for this application could begin in three to five years. The technique could have widespread uses, especially in situations where medicines can be harmful to healthy tissues, for example in chemotherapy.