Published On Jan 28, 2015
Feeling Nature’s Pull
Researchers have harnessed the power of the immune system to remove foreign pathogens from the blood.
Sepsis is a life-threatening medical condition caused by a hyperactive immune response to systemic infection. This response, known as a cytokine cascade, triggers severe inflammation throughout the body that can result in the failure of numerous organ systems. Because of a lack of effective diagnosis and treatment, the disease ranks among the top causes of death in the United States and incurs more than $20 billion in annual treatment costs.
“The majority of the time, you don’t know what the patient is infected with when they are diagnosed with sepsis,” says Donald E. Ingber, director of the Wyss Institute for Biologically Inspired Engineering at Harvard University. “Essentially, if you can get rid of the pathogen and released toxins, you get rid of the initiators of the cytokine cascade."
The Wyss Institute, notable for applying biological principles to develop new engineering innovations, has developed a mechanical approach to sepsis treatment, inspired by the filtering properties of the human spleen, an organ that uses interwoven microchannels to cleanse the blood of toxins and dead cells.
The new sepsis treatment device mimics the spleen’s microchannels. It uses two hollow channels connected by a series of slits. One channel carries the flowing blood, and the other contains a solution that captures foreign pathogens using a genetically engineered version of a naturally occurring blood protein called Mannose Binding Lectin (MBL). MBL is a component of the body’s innate immune system, and “is known to bind to more than 90 different pathogens and toxins," Ingber notes. The researchers used magnetic nanobeads coated in the engineered MBL to capture the offending substances and remove them from the blood using magnetic forces.
“Using this technology, we can bind a diverse array of pathogens in the blood whether they are dead or alive, and we can remove them from blood without having to first identify them,” says Ingber.
By reducing the number of pathogens in the blood, the device will improve treatment by eliminating the underlying cause of the septic response. The MBL technology, if effective, might have other applications, such as food safety testing or water purification.