Researchers have fabricated model blood vessel systems with diameters as narrow as the smallest capillaries in the body. The systems were used to study the activity of white blood cells as they were affected by drugs that tend to make them softer, which facilitates their entry into blood circulation. Photo: Rob Felt
LET'S GET PHYSICAL
Simple physics may play a larger role than previously thought in helping control key bodily processes, including how the body fights infection.
Using a model blood vessel system built on a polymer microchip, researchers have shown that the relative softness of white blood cells determines whether they remain in a dormant state along vessel walls or enter blood circulation to fight infection. Changes in these cell mechanical properties — from stiff to soft — can be triggered as a side effect of drugs commonly used to fight inflammation or boost blood pressure.
Better understanding the role of physics in fine-tuning such biological processes could give researchers new approaches for both diagnosing and treating disease.
The work, believed the first to show how biophysical effects can control where white blood cells are located within the blood circulation, was reported in the journal Proceedings of the National Academy of Sciences. The research was supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health, the National Science Foundation, and the American Heart Association.
“We are showing that white blood cells, also known as leukocytes, respond physically to these drugs and that there is a biological consequence to that response,” said Wilbur Lam, an assistant professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “This may suggest new ways to treat disease, and new places to look for diagnostic information. There may be physics-based disease biomarkers that we can use in addition to the common biological and biochemical markers we have been using.” — John Toon