Device uses magnetic nanoparticles to fight infections

Nature : The primary purpose of the spleen is to act as a blood filter. Now, Donald Ingber of the Wyss Institute for Biologically Inspired Engineering in Boston, Massachusetts, and his colleagues have created an artificial “biospleen” that uses magnetic nanoparticles to filter pathogens from blood. Ingber’s team coated magnetic nanobeads with a modified version of mannose-binding lectin, a protein that binds to the sugars on the outside of bacteria, viruses, fungi, and their toxic byproducts. The researchers fed blood into the device in which the nanoparticles were present and then used a magnet to pull the particles out of the blood along with any pathogens that had become attached; then the filtered blood was fed back into the patient. The device was tested on rats that were infected with either Escherichia coli or Staphylococcus aureus. Use of the biospleen filter increased the survival rate from 14% to 89%. Analysis of the blood after it was filtered showed that more than 90% of the bacteria had been removed. Ingber believes the device could be useful for stabilizing patients so that the immune system can eliminate the remaining traces of the infections and for fighting viral infections such as Ebola and HIV.