Magnetic Nanoparticles: The Newest Combatant Against Blood Infections and Sepsis
Scientists for the past few decades have been implementing the newest technologies to revolutionize medical treatment. This past week, researchers at the Harvard Wyss Institute for Biologically Inspired Engineering published their research in Nature on a new form of sepsis treatment: blood cleansing through an artificial biospleen.
Sepsis is a life-threatening whole-body inflammation that results from a blood infection, most commonly from the lungs. The infection arises when bacteria, parasites, viruses, and/or fungi enter the bloodstream, and can ultimately lead to multiple organ failures. The most common treatments today use intravenous fluids (IV) and antibiotics to cleanse the blood of pathogens. However, according to Don Ingler, founding director of the Wyss Institute, doctors are often unable to identify the specific pathogens circulating the bloodstream. Thus, doctors inject enormous quantities of drugs into the patient in hopes that one drug would hit the jackpot and eliminate the pathogen(s).
In well-financed hospitals, sepsis treatments can be performed without too many complications. However, in more remote environments such as battlefields, where people are more exposed and likely to fall victim to sepsis, the modern treatment for sepsis can be difficult to carry through successfully. With this in mind, bioengineers at the Wyss Institute engineered a device that completely does away with complicated antibiotic treatments and instead uses magnetic nanoparticles to cleanse the septic blood of pathogens. According to Joo H. Kang, a Technology Development Fellow at Wyss, this bio-spleen device is designed to “mimic the function and microstructure” of the spleen by continuously filtering pathogens out of the blood. Blood is flown through the biospleen and mixed with nanoparticles coated with a “capture agent” that attaches to pathogens. In this case, the “capture agent” is a modified version of an immune protein commonly found in our bodies called Mannose-binding Lectin, or MBL. The modified MBL binds with a greater variety of pathogens than the normal protein; tested on rats, the modified-MBL coated magnetic beads were found to bind with over ninety different pathogens. As such, after the blood is mixed with the nanoparticles, there is a higher chance that the pathogen(s) within the bloodstream will be enveloped by the nanoparticles. The blood then flows through a series of magnets that remove the nanoparticle-covered pathogen out of the blood. The cleansed blood is then returned into the body, and the cycle continues until most of the pathogens are removed and the infection is under control. The remaining infection, usually found in the organs, can be easily fought off with antibiotics and the immune system.
Sepsis currently has a 50% mortality rate and is one of the most lethal conditions worldwide. While this new biospleen is in the process of being tested on pigs, blood filtration and dialysis is already a common practice in hospitals, so we probably won’t have to wait very long before these devices hit the market. When this biospleen is approved for use on humans, combating sepsis and other diseases (such as HIV and Ebola) will no longer be a daunting task for doctors around the globe.