Clemson researcher places hope on pushy photons


CLEMSON -- Using a laser to push cells around may reduce heart problems and detect cancer at the cellular level.

"Light exerts a force," said Bruce Gao, assistant professor of bioengineering at Clemson University. "It's too weak to be noticed by us, but it can move atoms and cells."

The Clemson bioengineer has developed a method that uses laser beams to line up cells like dominos. Oak Ridge Associated Universities has funded Gao to further develop his laser cell guidance system and apply it in bioengineering research.

Gao's laser system is a highly sophisticated batting cage. Like a bat, a laser beam can direct only one cell at a time. The cells are held in a container, and a laser guides them out one by one. The beam leads them into another intersecting beam of higher intensity. The second beam then guides the cell to the target location.

An understanding of cell communication can lead to new treatments for disease. For example, the heart is made up of billions of cells that send chemical, electrical and mechanical messages to each other.

"We use the laser beam to create a pattern of multiple cell types, simulating the tissue environment on a small scale so we can isolate cell communication," Gao said.

It is difficult to isolate messages that stimulate specific responses -- for example, the message that triggers the replacement of dead cells with scar cells in heart muscle. Scar tissue makes heart muscle stiff and can lead to a heart attack. If scientists understand this message, they could change it. Instead of building scar tissue, the cells could stimulate new growth.

Cells react differently to light based on their size, density and shape. Compared to a basketball, a football is smaller, harder, shaped differently and bounces differently. Compared to normal cells, cancer cells are smaller, more dense and wrinkled, like a raisin. Gao proposes that cancer cells will react differently in response to his laser-beam system.

Early detection of cancer is a critical indicator of survival rates. The ability to detect cancer at the cellular level -- before a tumor has a chance to grow -- will help save many lives, according to Gao.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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