Researchers at Harvard University are developing a medical device that replicates the function of the human spleen. The scientists say that it can filter pathogens from E. coli bacteria to the Ebola virus. The device, called a biospleen, is under development at Harvard’s Wyss Institute for Biologically Inspired Engineering.
The device was primarily developed to treat sepsis, which is a blood infection. The biospleen filters out live and dead pathogens along with dangerous toxins that these pathogens sometimes create. The device removes the pathogens and toxins without having to identify them first. As drug-resistant bacteria continue to evolve and develop, creating a device that will remove these pathogens from the blood quickly without a diagnosis is becoming critical to medicine.
The biospleen is made up of two adjacent hollow channels connected with slits. Nanometer-sized magnetic beads in the device are coated with a “genetically engineered version of a natural immune system protein called mannose binding lectin (MBL).” MBL has a head and tail. In the human body, the head binds to sugars on the surfaces of bacteria, viruses, protozoa, and toxins. The tail tells the body’s immune system to destroy those compounds.
The protein was attached to magnetic brands that are one-five hundredths the width of a human hair that can be added to a patient’s blood. The biospleen has a magnet that pulls the beads through the channels to clean the blood, which then circulates back into the patient. In tests, more than 90% of pathogens were bound and removed. The devices can be linked to achieve rates similar to dialysis.
The scientists have tested the device on rats that were infected with Staphylococcus aueus or E. coli, two of the major food poisoning bacteria. The device filtered 90% of the bacteria out of the blood and decreased inflammation levels. Overall, 89% of the rats treated with the biospleen survived. Only 14% of the rats who were not treated survived.
