Changing Blood-Cell Shapes Provide Clues for Fighting Disease

Living cells are not constant little balls. Responding to various chemical and temperature changes, cells change their shape and their volume. The outer layers (membranes) of red blood cells, for example, can change by tens of nanometers on time scales of tens of milliseconds. At the recent Optical Society of America annual meeting in Rochester, N.Y., an MIT group showed how they measured such tiny, quick fluctuations, and how they are related to the cell's osmotic behavior -- that is, to the cell's ongoing effort to maintain a balance in the concentration of ions between itself and its surroundings. It can do this, for instance, by admitting or expelling water.

If the osmotic imbalance becomes too great, however, the cells can burst, an action called lysis. Often diseased cells are more prone to lysis, which in turn is signaled by changes in the way the membrane flickers (a swelling cell flickers less), hence the interest in numerically monitoring activity at the cell’s boundary.

Gabriel Popescu (gpopescu@mit.edu), a researcher in the MIT laser spectroscopy lab of Michael Feld, says that their optical microscopy measurements of the role of osmotic pressure in red blood cell flickering are likely to help in understanding clinical problems such as the effects of the malaria parasite on the red blood cell membrane and changes in the mechanical properties of the cells during sickle cell disease. Such basic knowledge, largely unknown until now, paves the way toward better understanding and strategies for treating those and many other diseases involving red blood cells.

OSA meeting Web site
Contact Gabriel Popescu
Massachusetts Institute of Technology
gpopescu@mit.edu
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