Researchers at MGH have engineered living cells to emit green laser light, which might one day kill cancer cells with light-based therapeutics.
Malte Gather/Andy Yun
The typical laser uses inert materials, but those recently created by MGH researchers have a different, living origin: a single cell. Andy Yun, a biomedical scientist with a doctorate in physics at MGH’s Wellman Center for Photomedicine, and Malte Gather, a research fellow in Yun’s lab, genetically programmed cells derived from a human kidney to produce green fluorescent protein and placed them in a microcavity formed by two parallel mirrors just one cell wide. With a customized microscope, they exposed a cell to a pulse of blue light, which caused the cell to emit pulses of green laser light, as shown in the 3-D schematic at left. Instead of simply producing weak fluorescence, emitting light randomly in all directions, the mirrors made the light bounce back and forth, increasing the strength of the emission to a coherent laser beam, thousands of times stronger than fluorescence. Light moves back and forth through a cell a thousand times or more, as opposed to once with fluorescence, giving researchers the ability to amplify signals from a cell in a way much more powerful than before.
Yun sees great potential in the technology. “We might be able to use light to detect intracellular processes with a high level of sensitivity,” he says. “Or instead of trying to deliver external laser light deep into tissues—as is done in light-based therapeutics, for example, to kill cancer cells—a cell laser might provide light from within.”