Diffraction phase microscopy provides insight into how cells interact

Several years ago, ECE Assistant Professor Gabriel Popescu teamed up with some colleagues at MIT on a project to test the elasticity of red blood cells, a development that can be used to diagnose and treat malaria, among other diseases.

“We had developed this new microscopy technique, which I called ‘diffraction phase microscopy [DPM],’ that was special in the sense that it was able to pick up very tiny motions in live cells, down to the nanometer scale,” said Popescu.  “This level of sensitivity was out of reach for existing light microscopes.”

Popescu’s involvement in the MIT project stemmed from his ability to perform DPM quickly and accurately on both the nanometer and millisecond scales.  Popescu said his group at MIT began looking at red blood cells due to their interesting structure and behavior. The elasticity of these cells is their most important property, and their flexibility or stiffness can be an indicator that something is wrong.

“If they become stiff, that is a sign of various diseases,” said Popescu. “They cannot accomplish their task of delivering oxygen to the body, and, thus, are then discarded from circulation.”

Last year Popescu joined the University of Illinois to continue his research on DPM in areas beyond red blood cells. He said this year has been very fruitful, and he has been able to take the project to another level, teaming up with the Department of Cell and Developmental Biology to determine the success of this microscopy technique on brain cells.

“Over the past year I’ve developed collaboration with Martha Gillette’s group and now we’re looking at brain cells, mostly neurons and glial cells,” he said. “We’re also able to pick up motions on the nanometer scale, but they’re not only due to the membranes, but to many other phenomena.   So the problems are much more complex and much more interesting.”

Popescu said they are looking at the trafficking of very tiny quantities of fluid in live cells, basically looking at how neurons interact with one another and how the brain functions. The team currently has one published paper, with a few more within the publication process. However, neuroscience is only one direction that Popescu is going.

Popescu believes the malaria-related research is just the beginning.  This optical technique may have clinical potential, and it may be used to test drugs and perhaps even to reverse the effects of a variety of diseases, such as cancer.

“We just started working with breast cancer and we’re first looking at the structure, how the tissue changes as the breast cancer sets in and develops,” he said.

Popescu said that this new breast cancer research and measurement is going on right now and that the next level is to look at the dynamics in vivo, meaning that, with the onset of cancer, the tissue looks different, but it may sound different, too. They are looking at how the cancer cell dynamics changes in relation to a normal cell.

“There are a lot of new projects going on right now,” said Popescu. “We’re excited to see where they will take us.”