I have to say I cringe every time I see an advertisement for some magnet based item that promises health benefits. I’ve ragged on these Magnet Therapies before but today I’d like to cover one of the ways that magnets are legitimately being used to treat medical problems. A couple of months ago a study was published in the The Journal of the American College of Cardiology: Cardiovascular Interventions (a mouthful huh?) that detailed the use of magnetic nanoparticles and an externally applied magnet in guiding cells inside the body to a site of injury.
Specifically the study attempted to tag a particular type of stem cell, Endothelial Progenitor Cells (EPCs), with iron oxide superparamagnetic* nanoparticles. This was rather simply achieved by the addition of the particles to the growth medium of the cells. The cells then took up the particles via endocytosis. Once this was done they injected the cells into rats whose carotid artery had been damaged by angioplasty. A magnet was then applied to the outside of the rat to attract the tagged cells to the site of the damage. This technique showed a 5-fold increase in cells attaching to the damaged area compared to not using the magnet.
The difficulty of getting the cells to the right place without the magnet is due to the rapid blood flow past the injury. Imaging being swept down a fast flowing river with the goal of grabbing onto the river bank at a particular spot, not that easy, if there are thousands of you doing it some will manage but most will be carried right past. The addition of the magnet is like throwing a rope out to the hapless swimmers, once they get that helping hand they can then clamber onto the bank on their own. The EPCs will naturally attach themselves to places where damage is evident but under the high flow rates in arteries this process is inefficient.
This technique is specifically tailored to helping repair damage caused by angioplasty and it is hoped that it’s use might reduce the occurrence of Restenosis, or the re-narrowing of arteries after they have been widened by the angioplasty procedure. Even so, the guidance of the cells by magnetic field has obvious applications for other types of stem cell therapies as well as targeting drugs and gene therapies to specific organs of areas of the body.
Magnets are awesome.
*This sounds like a good name for a cheesy super hero, Superparamagnetic Powers Activate!.