Scientists have demonstrated that living cells can be influenced and made to move towards sources of light, a discovery with many medical applications.
Edit: We were contacted by the lead author of the study, Dr. Ajith Karunarathne, who informed us that we had unfortunately made a mistake regarding Dr. Gautam's name. We apologize for this error and have corrected it. We hope Dr. Gautam, the research team involved, as well as our readers, haven't been inconvinienced by the mistake. Sorry!
Researchers at Washington University School of Medicine in St. Louis have discovered a way to make cells move, marking an important first step towards using light as a means of controlling insulin secretion and heart rate.
Dr. N Gautam, PhD, a professor at the school's department of Anesthesiology, explains that the light functions as an on-off switch for the cells "Much of the way cells behave is due to their ability to sense signals in the environment. In these experiments, what the cells sense is the presence of light."
The cells in question were immune cells, manipulated by adding a light-sensitive protein. Once added, the cells needed only to be shined on by a laser in order to be coaxed into moving in a desired direction.
Dr. Gautam and his team of researchers have the ultimate goal of perhaps finding ways of manually activating receptors on the cells’ exterior. "It's what happens naturally when an immune cell senses something amiss in its environment and then migrates toward that potential trouble, perhaps a bacterial infection or inflammation," says Gautam.
The scientists used genetic engineering to infuse the cells with the light sensing protein Opsin, something which exists naturally in the eyes of humans and other animals. In the future, they hope to expand upon the technique by introducing several different proteins, which all react to different wavelengths of light, increasing the possibilities in how the cell can be controlled.
Gautam explains the many possibilities for the new technique: "We can control migration of cells, which is important not only to the immune system but also during embryonic development to ensure that cells that make the heart, liver and other organs go to the right place. It's also key in cancer metastasis, when a tumor releases cells that migrate to other parts of the body. We are excited by the many possibilities."