Sepsis is an nasty and surprisingly common way to die. The illness is triggered by blood infections but, ultimately, it's your own immune reaction — not the bacteria or virus — that poisons you to death. Filtering those pathogens out of blood right away, though, could be a promising treatment. Enter a new device made of magnetic nanobeads coated in sticky proteins that attract bacteria, viruses, and fungi.
Scientists at Harvard's Wyss Institute for Biologically Inspired Engineering have created what is essentially an artificial spleen. The device made of wire and plastic may not resemble the fleshy organ in our bodies, but its series of blood channels mimics the microarchitecture of spleens.
Blood passing through these channels encounters magnetic nanobeads coated with a protein called mannose-binding lectin (MBL). MBL is a natural immune protein that binds to the surfaces of bacteria, viruses, fungi, pathogen, and toxins; this super general binding is deliberate because sepsis can be caused by any number of microbes. The nanobeads can then be easily filtered from the blood, pathogens and all.
So far, the "biospleen" has been tested on rats with blood infections. The next trials are on pigs and eventually, if all goes well in a couple years, in humans. For the leading cause of death in hospitals, a new treatment for sepsis could not come soon enough. [Harvard, Nature Medicine]
Picture: Nanobeads binding bacteria, E. coli (blue) and S. aureus (orange). Harvard's Wyss Institute