Nanomagnets clean blood

For a number of clinical conditions, removing the disease-causing factor from blood would be the most direct cure. For example, dialysis filters urea out of a patient’s blood as a treatment for renal failure. However, this clinical approach is limited by particle size because high molecular weight compounds are more difficult to remove by filtration.

The researchers have developed a device that connects the carotid artery with the jugular vein outside the body. The device uses magnetic iron carbide nanoparticles with capturing agents attached to their surfaces to remove larger molecules from the blood. The target toxins bind to the capturing agents as they collide within the circuit, then the magnetic nanoparticles are removed from the blood with the toxin attached by magnetic separation before the particles re-enter the blood circulation. The nanoparticles are encapsulated in carbon to prevent the iron core from oxidising and losing magnetism.

The scientists used their extracorporeal circuit to remove lead and digoxin from rats. They found that 40 per cent of the toxins were removed within 10 minutes and over 75 per cent of the toxins were removed after 40 minutes.