http://www.medscape.com/viewarticle/590 ... ac=48517EX
Magnetic Blood-Cleansing Device May Improve Sepsis Outcomes
NEW YORK (Reuters Health) Mar 31 - US researchers have developed an extracorporeal magnetic cleansing device that can rapidly remove over 80% of fungi in contaminated blood.
Senior researcher Dr. Donald E. Ingber, from Harvard Medical School, Boston, believes that use of the multiplexed micromagnetic-microfluidic separation system, as it is called, could improve the treatment of sepsis.
"This blood-cleansing microdevice offers a potentially new weapon to fight pathogens in septic infants and adults, that works simply by removing the source of the infection and thereby enhancing the patient's response to existing antibiotics," Dr. Ingber said in a statement.
According to the report, first published online on February 18th by the journal Lab on a Chip, current treatments for sepsis are suboptimal, in large part because they do not fully remove the offending pathogen from the blood. As a result, toxins continue to circulate and promote the shock state.
The cleansing device was created by modifying immunomagnetic microbeads to become magnetic opsonins; i.e., the beads were coated with pathogen-specific antibodies. The microbeads are introduced into blood flowing through the system, bind to the pathogens, and are pulled out by a magnet. Thus the device allows for the continuous and rapid separation of pathogen from flowing blood.
In the current study, the researchers tested the device on blood contaminated with Candida albicans, a pathogen responsible for many sepsis-related deaths. Using a multiplexed version of the device with four parallel channels, the authors were able to clear over 80% of fungi from the blood at a flow rate of 20 mL/hour in one pass, which is roughly 1000 times faster than the rate achieved with a previously described prototype device.
"These results provide the first proof-of-principle that a multiplexed micromagnetic-microfluidic separation system can be used to cleanse pathogens from flowing human blood at a rate and separation efficiency that is relevant for clinical applications," the authors conclude.
Lab Chip 2009.