"Biospleen" Cleans Infections from Blood
Scientists have developed a device, inspired by the spleen, that is designed to filter many different types of infections from the blood. The “biospleen” filters blood using magnetic nanobeads which bind to bacteria or viruses and remove them from the blood.
The biospleen can be used to treat blood infections, which are often deadly, even when the specific organism causing the infection is unknown.
A team led by Donald Ingber, a bioengineer at the Wyss Institute for Biologically Inspired Engineering in Boston, Massachusetts, designed the biospleen. The device uses magnetic nanobeads coated with a modified version of mannose-binding lectin (MBL), which is a protein that binds to sugar molecules that can be found on various infecting organisms, including bacteria, viruses, and fungi. Blood enters the device, which binds the infecting organism. The magnetic beads are then pulled out of the blood, along with their trapped quarry, and the cleaned blood is then returned to the patient.
The device has been tested on rats that were infected with either E.coli or Staphylocuccus aureus, two common bacteria that can cause sepsis. One group of rats was treated with the biospleen, the controls were not. After five hours 89% of the treated rats were still alive, while 14% of the control rats were alive. The team is now testing the device on pigs, and plan human trials within a couple of years.
The test device is capable of effectively filtering a liter of blood per hour, which is sufficient to filter the entire volume of blood in an adult human in five hours. This could prove a very effective diagnostic tool and treatment for blood infections, including Ebola, HIV, other viruses, bacteria, and fungi.
The analogy with the spleen comes from the fact that the spleen is essentially a filter, although its primary function is to filter old and damaged red blood cells from the blood. It also removes antibody coated bacteria from the blood, and is therefore an important part of the immune system.