Researchers develop light-responsive heart cells

Sept. 26, 2011, 2:02 a.m.

Stanford researchers announced the development of heart cells that can be paced with a light technology known as “optogenics” in a study published last week.

The researchers, including lead author, postdoctoral scholar and doctoral candidate in bioengineering Oscar Abilez, described the ramifications of their invention in a press release by the Schools of Medicine and Engineering.

“In the near term…the advance will provide new insight into heart function,” the statement said. “In the long term, however, the development could lead to an era of novel, light-based pacemakers and genetically matched tissue patches that replace muscle damaged by a heart attack.”

The researchers developed the cells by inserting a light-sensitive protein into human embryonic stem cells. The protein controls the flow of ions, especially sodium, in and out of the cells and therefore manages their pacing. When the protein is exposed to a special wavelength of blue light, it opens channels in the cell membrane to allow an influx of sodium, creating a contraction.

Optogenics technology, which can be used to control a variety of mammal cells, was invented by Karl Deisseroth, assistant professor in bioengineering as well as psychiatry and behavioral sciences.

The long-term goal of creating light-based pacemakers resolves issues seen in today’s devices.

“Pacemakers fail mechanically. The electrodes can cause tissue damage,” Abilez said.

“Defibrillators, on the other hand, can produce tissue damage due to the large electrical impulses that are sometimes needed to restore the heart’s normal rhythm,” said Ellen Kurl, senior author of the study and professor of mechanical engineering.

For example, researchers explained the design behind a pacemaker that would not touch the heart itself but instead control the surrounding pericardium tissue.

“Instead of surgically implanting a device that has electrodes poking into the heart, we would inject these engineered light-sensitive cells into the faulty heart and pace them remotely with light, possibly even from outside of the heart,” said Christopher Zarins, professor emeritus of surgery and director of the lab where the experiments were performed.

–Ellora Israni



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