Physicists Malte Gather and Seok Hyun Yun have created what sounds like the origin of a comic book superhero: a functioning biological laser operated by human cells.
Live, glowing embryonic human kidney cells at the heart of the biolaser can absorb, amplify and emit light in a concentrated beam. In the past, lasers have done this through semiconductors, crystals, dyes and even gases. This is the first time biological material has been used for this function.
The kidney cells are able to function as foci for laser beams because they are reprogrammed to include the GFP gene. This gene, found in bioluminescent creatures like deep-sea jellyfish, has been successfully transferred to many animals.
During the laser process, in which the cells were sandwiched between highly reflective mirrors and lit by a blue light, the cells absorbed and re-emitted a laser-worthy green light for several minutes. The mirrors amplified the light to create a coherent beam, just as they do in non-biological lasers. The cells survived for a few hours after the experiment, and still seemed to be producing and reabsorbing the green fluorescence protein. This could mean that, unlike regular lasers which wear out with use, the biolaser heals itself.
These new lasers could literally shed light on the biological process inside the cells because the beam could be used as a living imaging tool. Biolasers could also have medical applications. Some treatments use external lasers to stimulate drugs to be released close to a tumor. Using an internal laser would probably be a lot more efficient and safe.
The next step for researchers is to free the biolaser from its optical chamber, hopefully by somehow incorporating tiny mirrors into the cell.