Artificial filter ‘cleans’ infected blood with magnets.
Researchers have developed a filter that can remove 90 percent of infectious microbes in blood. Unofficially dubbed “the Biospleen,” the blood-cleansing device shows promise in fighting a wide-range of infections and diseases, including currently untreatable pathogens like HIV and the Ebola virus.
A team of researchers, mainly from the Wyss Institute for Biologically Inspired Engineering in Boston, Massachusetts, created the device in an effort to find new ways of fighting sepsis, which is a severe body-wide inflammatory response to infection. Sepsis, also known as blood poisoning, affects 18 million people around the world annually. Sepsis has a 50 percent mortality rate, even in countries with the best medical care. 10,000 Canadians die of sepsis annually, making it a prominent cause of in-hospital death.
A heavy dose of antibiotics, sometimes administered before the pathogen causing the affliction is known, is the typical treatment for Sepsis. It requires numerous types of antibiotics each catered to a potential infective agent. The intensity of the application raises concerns for antibiotic resistance.
The Biospleen starts by removing infected blood from a host. Upon exiting the body, the Biospleen mixes the blood with countless magnetic nanoparticles coated in Mannose-binding Lectin (MBL), a protein used by our body’s immune system to identify unknown pathogens. The MBL clings to pathogens in the blood, carrying them along with the nanoparticles. Then, a magnetic field draws the nanoparticles away from the blood, with the pathogens in tow, before the filtered blood re-enters the host’s bloodstream.
Initial indications of the Biospleen’s efficacy are promising. The study infected rats with a range of dangerous microbes, such as Staphylococcus and E. coli, and then applied the blood filter. Rats which were infected but then not treated had an 86 percent mortality rate. Rats treated with the Biospleen had only an 11 percent mortality rate.
Testing human blood showed equally promising results. The Biospleen reduced pathogenic presence in donated blood by 90 percent, and was capable of filtering one liter of blood an hour. The average human body contains about 5 liters of blood. This means the Biospleen might reach this pathogenic reduction rate across the entire body in 5 hours, which may be enough time to control sepsis, according to the study.
The study also suggests this new infection-fighting method may also apply to diseases without cures. MBL adheres to a wide range of pathogens, including HIV and the Ebola virus.
The Biospleen can’t cure disease, but it can be controlled to provide an opportunity for drug treatment or other medical action. Pathogens usually infect bodily tissues as well blood, meaning antibiotics or other drugs would need to be administered to completely cure an individual of them.
While the study’s preliminary results are promising, its authors cautioned that further testing is required before human trials begin. Lead author of the publication Donald Ingber said that its first clinical application may be years away.