'Bio-Spleen': A breakthrough for treating blood-borne pathogens

The treatment of many blood-borne illnesses has reached a breakthrough with the recent announcement of a device able to cleanse the blood of disease pathogens. 

Scientists at the Wyss Institute for Biologically Inspired Engineering in Boston have developed an “extracorporeal blood-cleansing device for sepsis therapy.” In layman’s terms, the device is an engineered spleen that, in the absence of a normally-functioning one, is able to cleanse blood of impurities such as E-coli and other precursor bacteria that causes diseases such as Ebola.

Blood-borne infections are notoriously difficult to treat, and if medical intervention is too slow, they can cause sepsis, a potentially fatal immune response. More than half of the time, physicians are unable to diagnose exactly what caused the sepsis in the first place, which often leads to them prescribing antibiotics which kill a wide range of bacteria and sometimes produce undesired side-effects. Another important consideration throughout this treatment process is the formation of super resilient bacteria that become immune to antibiotic treatment.

How this super spleen works

With this in mind, bioengineer Donald Ingber and his team set out to develop an artificial spleen that is able to filter blood through the use of proteins and magnets. More specifically, the device uses modified mannose-binding lectin (MBL), a human protein that binds to sugar molecules on the surface of over 90 bacteria, viruses, and fungi, as well as the toxins released by dead bacteria that cause sepsis in the first place.

By adding MBL to magnetic nano-beads and passing blood through the device, the pathogens in the blood bind to the beads. A magnet then pulls the beads and their constituent bacteria from the blood, which is now clean and able to be put back into the patient.

Ingber and his team tested the device on infected rats, and after finding that 89% of infected rats were still alive by treatment’s end, wondered whether the device could handle the blood load of an average human adult (about five litres). By passing similarly-infected human blood through the device at 1L/hour, they found the device removed the vast majority of pathogens within five hours.

Once the bulk of the bacteria is removed from the patient’s blood, their immune system can handle their weakened remains. Ingber is hopeful that the device will be able to treat larger-scale diseases, such as HIV and Ebola, where the key to survival and effective treatment is to lower the pathogenic level of the patient’s blood before attacking the disease with powerful medicine.