Using optogenetics, a Stanford group creates optically triggered heart cells

Sept. 23, 2011
Palo Alto, CA--A multidisciplinary group at Stanford University has developed human heart cells that can be paced with light via optogenetics.

Palo Alto, CA--A multidisciplinary group at Stanford University has developed human heart cells that can be paced with light via optogenetics.1

Optogenetics allows a light-sensitive protein such as channelrhodopsin-2 (ChR2) or others to be encoded into DNA to produce mammalian tissues that are responsive to light. For the light-responsive heart cells, DNA encoding ChR2 was inserted into human embryonic stem cells. ChR2 controls the flow of electrically charged ions into the cell. For heart cells, the primary ion is sodium, which initiates an electrochemical cascade that causes the cell to contract. The optogenetically engineered stem cells were then transformed into light-sensitive cardiomyocytes.

The genetically engineered form of ChR2 responds strongly to light at a 470 nm wavelength. The result is an influx of electrically charged sodium into the cells, producing a contraction.

Lab-created cells, computer-modeled uses

After creating the cells in a laboratory dish, researcher Oscar Abilez turned to co-researcher Ellen Kuhl, whose specialty is sophisticated computer modeling of the human body. Using her algorithms, they tested the new cells in a computer simulation of the human heart, injecting the light-sensitive cells in various locations in the heart and shining a virtual blue light on them to observe how the injections affected contraction as it moved across the heart.

"In a real heart, the pacemaking cells are on the top of the heart and the contraction radiates down and around the heart," says Kuhl. "With these models we can demonstrate not only that pacing cells with light will work, but also where to best inject cells to produce the optimal contraction pattern."

The long-term goal is a new class of pacemakers to supersede the commonplace surgically implanted electrical pacemakers and defibrillators. "We might, for instance, create a pacemaker that isn't in physical contact with the heart," said Christopher Zarins, another researcher. "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."

The leads for such a light-based pacemaker might be placed outside the heart, but inside the pericardium (the protective sack surrounding the heart). Or, a pacemaker could be placed inside the heart chambers (like traditional pacemakers) producing light that would travel through the intervening blood to pace light-sensitive heart cells implanted inside.

REFERENCE:

1. Oscar J. Abilez et al., Biophysical Journal, Vol. 101, No. 6, p. 1326, 21 September 2011.

About the Author

John Wallace | Senior Technical Editor (1998-2022)

John Wallace was with Laser Focus World for nearly 25 years, retiring in late June 2022. He obtained a bachelor's degree in mechanical engineering and physics at Rutgers University and a master's in optical engineering at the University of Rochester. Before becoming an editor, John worked as an engineer at RCA, Exxon, Eastman Kodak, and GCA Corporation.

Sponsored Recommendations

Melles Griot® XPLAN™ CCG Lens Series

March 19, 2024
IDEX Health & Science sets a new standard with our Melles Griot® XPLAN™ CCG Lens Series fluorescence microscope imaging systems. Access superior-quality optics with off-the-shelf...

Spatial Biology

March 19, 2024
Spatial Biology refers to the field that integrates spatial information into biological research, allowing for the study of biological systems in their native spatial context....

Custom-Engineered Optical Solutions for Your Application

March 19, 2024
We combine advanced optical design and manufacturing technology, with decades of experience in critical applications, to take you from first designs to ongoing marketplace success...

Semrock Optical Filters Resources

March 19, 2024
Looking for more information about Semrock optical filters? Explore sets by fluorophore, download the 2023 Semrock catalog and more.

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!