Tiny channel cleanses blood

Margination, the natural phenomenon where bacteria and leukocytes (white blood cells) move toward the sides of blood vessels, is the inspiration for a novel method for treating sepsis, a systemic and often dangerous inflammatory response to microbial infection in the blood.

A team of researchers at the Massachusetts Institute of Technology and the National University of Singapore has designed a branchlike system of microfluidic channels, 20 micrometers (20 millionths of a meter, or about one-fifth the size of a grain of sand) high by 20 micrometers wide, that mimic the marginizing action of vessels on bacteria and inflammatory cellular components (leukocytes and platelets) to separate them from .

The microchannel network is etched onto a polymer chip by the same techniques used for manufacturing . As infected whole blood flows through the first part of the microchannel, red cells migrate toward the center while the unwanted cell types flow toward the side walls. Like a biological railway junction, the second part of the microchannel is divided into three branches with red cells taking the middle path and the marginated microbes, leukocytes, and platelets moving into the two outer ones. A second three-branch junction further purifies the red cell fraction, which could then be returned to a patient in a real-life situation.

In their experiment with the prototype device, the researchers demonstrated highly efficient removal of the bacteria Escherichia coli (80 percent) and the yeast Saccharomyces cerevisiae (90 percent) as well as a greater than 80 percent depletion of inflammatory cellular components. The researchers also designed and tested a larger blood cleansing system consisting of six microfluidic channel networks in parallel.

Currently, they are conducting a small-scale animal test to validate the efficacy of the technique in vivo. Article "A microfluidics approach towards high-throughput pathogen removal from blood using margination" is accepted for publication in Biomicrofluidics.

add to favorites email to friend print save as pdf

Related Stories

Using magnets to help prevent heart attacks

Jun 07, 2011

If a person's blood becomes too thick it can damage blood vessels and increase the risk of heart attacks. But a Temple University physicist has discovered that he can thin the human blood by subjecting it to a magnetic field.

Red blood cell hormone modulates the immune system

Jan 20, 2011

New research reveals that a hormone best known for stimulating the production of red blood cells can modulate the immune response. The study, published by Cell Press in the January 27th issue of the journal Immunity, finds ...

Recommended for you

Gamers helping in Ebola research

10 hours ago

Months before the recent Ebola outbreak erupted in Western Africa, killing more than a thousand people, scientists at the University of Washington's Institute for Protein Design were looking for a way to stop the deadly virus.

Carcinogenic role of a protein in liver decoded

12 hours ago

The human protein EGFR controls cell growth. It has mutated in case of many cancer cells or exists in excessive numbers. For this reason it serves as a point of attack for target-oriented therapies. A study ...

A new way to diagnose malaria, using magnetic fields

Aug 31, 2014

Over the past several decades, malaria diagnosis has changed very little. After taking a blood sample from a patient, a technician smears the blood across a glass slide, stains it with a special dye, and ...

User comments