Artificial spleen cleans up blood

Researchers have developed a high-tech method to rid the body of infections — even those caused by unknown pathogens. A device inspired by the spleen can quickly clean blood of everything from Escherichia coli to Ebola. 

Blood infections can be very difficult to treat, and can lead to sepsis, an often-fatal immune response. More than 50% of the time, physicians cannot diagnose the cause of an infection that has prompted sepsis, and so they resort to antibiotics that attack a broad range of bacteria. This approach is not always effective, and can lead to antibiotic resistance in bacteria.

In search of a way to clear any infection, a team led by Donald Ingber, a bioengineer at the Wyss Institute for Biologically Inspired Engineering in Boston, Massachusetts, developed an artificial 'biospleen' to filter blood.

The device uses a modified version of mannose-binding lectin (MBL), a protein found in humans that binds to sugar molecules on the surfaces of more than 90 different bacteria, viruses and fungi, as well as to the toxins released by dead bacteria that trigger the immune overreaction in sepsis.

The researchers coated magnetic nanobeads with MBL. As blood enters the biospleen device, passes by the MBL-equipped nanobeads, which bind to most pathogens. A magnet on the biospleen device then pulls the beads and their quarry out of the blood, which can then be routed back into the patient.