Cleaning up bad blood

An external blood-cleansing device that mimics the spleen by rapidly and continuously removing pathogens and toxins from blood is described in a study published in Nature Medicine this week. The device, tested in rats, may lead to future potential treatments for human blood infections and septic shock, which leads to death in 30-50% of cases.

Don Ingber and colleagues developed a device, which uses magnetic nanobeads, coated with a genetically engineered version of a natural human blood protein (mannose-binding lectin), to capture a broad range of pathogens and toxins. Testing in rats, the authors showed that bead-bound pathogens and toxins could be pulled out of the flowing blood by a magnet. The cleansed blood was then be returned to the rat body without significantly altering its composition or causing coagulation.

The authors also demonstrated reduced levels of certain pro-inflammatory immune system cytokines known to play a role in the sepsis cascade and the removal of toxins that are key in a rat model of acute septic shock.