The study team, led by Robert J. Levy, M.D., the William J. Rashkind Chair of Pediatric Cardiology at The Children’s Hospital of Philadelphia, loaded endothelial cells, flat cells that line the inside of blood vessels, with nanoparticles, tiny spheres nanometers in diameter. The nanoparticles contained iron oxide.
Using an external, uniform magnetic field, Levy’s team directed the cells into steel stents inserted into the carotid arteries of rats. The uniform magnetic field created “magnetic gradients,” local regions of high magnetic force that magnetized both the nanoparticles and the stents, thus increasing the attraction between the particles and their target.
Levy’s team created nanoparticles, approximately 290 nanometers across, made of the biodegradable polymer, polylactic acid, and impregnated with iron oxide. The researchers loaded the nanoparticles into endothelial cells, which had been genetically modified to produce a specific color that could be detected by an imaging system while the animals were alive. After introducing stainless steel stents into rats’ carotid arteries, Levy’s team used magnetic fields to steer the cells into the stents.
“Magnetic fields produced by ordinary MRI machines could suffice to deliver cells to targets where they could promote healing, since MRI uses uniform fields, which are key to our targeting strategy,” added Levy. “This method could become a powerful medical tool.”
MEDICA.de; Source: Children's Hospital of Philadelphia