Boston Electric Engineers Create Living Lasers From Human Cells!

Scientists at the Harvard Medical School have collaborated with a team of researchers at the Massachusetts General Hospital to develop lasers using human cells. Yes, though it sounds freaky, it is very real. The Boston scientists have devised a way to generate cells that will act like laser diodes! The reason that inspired these scholars to invent such a thing was that it was quite difficult to get visible or infrared light inside and out of the human body. This led to many limitations and hindrances in various applications of biological imaging. So the scientists thought that why don’t we culture cells in the human body that will act as the light source themselves!With this objective in minds of the Boston engineers, the innovative technique got developed.
The basic components of an electronic laser are a light source, an amplifier, etc. The same list is also present in these new living lasers. The team genetically altered human liver cells into cells that emit green fluorescent proteins. These cells are actually the gain media that amplify the incident light energy. The researchers used a microscope to provide light energy to the cells in the test tube so that the light gets amplified. The light rays undergo total internal reflections and bounce off repeatedly against the cell walls. The photons gain sufficiently large amounts of energy during this time and finally released as a strong coherent laser beam. For travelling greater distances, the light must have sufficient energy. This is accomplished by keeping the cells
inside a minuscule, cell shaped biocompatible optical cavity.

The study got published as a paper in an issue of Nature Photonics, the researchers had hinted that this technology can one day be used for transmitting optically encoded information in and out of the body. Till now, a few experiments had been carried out to make human cells produce fluorescent proteins that emitted light. These cells are very useful for tagging and for detecting certain diseases in the body. They help us to study the molecular working of tissues and cells in the body. These fluorescent protein tags are widely used now days for understanding cell biology in test tubes. However, the main difference between this technology and the new laser cells is that the laser cells form a high intensity, directional, coherent beam of light that can travel some distance despite the losses due to diffusion. For example, it can contain information regarding biomarkers in the body fluids.
Although the concept and future applications of this new class of laser sound awesome, the main hurdle preventing their implementation inside the body is the lack of proper light source that will pump the laser. The researchers used a microscope for displaying the cells in a test tube but a microscope can’t be a practical solution inside your body. One alternative can be the use of biocompatible and implantable electronic devices like high quality LEDs, diodes, etc. that will act as the source for the fluorescent protein producing laser cells.