Magnetic Nanoparticles Banish Bacteria From Blood

When bacteria build up in the blood, it’s bad news. The condition can lead to a serious infection known as sepsis, which can turn deadly even with aggressive treatment using antibiotics. Researchers at Massachusetts Institute of Technology and Harvard Medical School may have found a way to pluck bacterial invaders from blood using magnets (Nano Lett., DOI: 10.1021/nl3047305). Daniel S. Kohane and coworkers coated magnetic nanoparticles with zinc-coordinated bis(dipicolylamine), a complex known to bind strongly to anionic phospholipids that densely decorate the surfaces of bacteria. The researchers added these modified nanoparticles to cow blood tainted with Escherichia coli and ran the blood through a magnetic microfluidic device. They were able to pull almost all of the bacteria from the blood, even at relatively high flow rates of 60 mL per hour. The technology, the researchers say, could be adapted to treat sepsis in people, which in the U.S. has become the seventh-leading cause of infant mortality and the 11th-leading cause of death.