Vivian Richardson, Ivanhoe Health Correspondent
CHICAGO (Ivanhoe Newswire) — It’s still a long way off, but one day doctors may use magnets placed both inside and outside a patient’s body to direct medications to a precise location. A new study reveals the concept works in animals.
Engineers and doctors at Drexel University in Philadelphia wanted to find a way to re-medicate stents — small wire mesh tubes used to hold blood vessels open. In the past, these “scaffolding” devices for diseased or damaged blood vessels would sometimes cause a new blockage until doctors developed drug-eluting stents. The medications coated on the device helps keep the vessels healthy. When the medication runs out, clots can sometimes form and lead to heart attacks or strokes.
“Stents are limited at this point to the single dose that is on the stent at the time of surgery,” Frederick Stoddard, M.D., a surgical resident at Drexel University College of Medicine, told Ivanhoe. He helped create and test a magnetic stent along with Zachary Forbes, Ph.D. When magnetized medications are injected into the patient, the drugs are attracted to the magnetic stent. “One of the great things about this is that we can target the stent with virtually any drug we want repeatedly. We can do this through intravenousinjection, which means you don’t have to do an additional invasive procedure,” Dr. Stoddard said.
The system has three parts. First, a paramagnetic stent is implanted in the patient. Paramagnetic means it is only magnetic when exposed to a magnetic field. Later, paramagnetic nanoparticles coated with medication are injected into the patient. Next, the patient and stent are exposed to an external magnetic source. In animal tests, Dr. Forbes said they were able to show that most of the medication gathered at the site of the stent and then stayed there.
Researchers need to do more work before the technique can be tested in humans. Dr. Forbes, however, said he is hopeful that the basic idea could help keep heart patients with stents healthier longer without further surgical treatments. “We think this is something that has a great opportunity to be clinically implementable down the line from now,” he said.
The idea of magnetic drug delivery could also be applied to other implants, for the knee or hip for example. “Anything we could do to prevent another replacement or revision surgeries,” said Dr. Forbes.
SOURCE: Ivanhoe interview with Zachary Forbes, Ph.D., and Frederic Stoddard, M.D., from Drexel University in Philadelphia, at the American College of Surgeons 2006 Clinical Congress in Chicago, Oct. 8-12, 2006