Immune Cells Light Up from Tiny Lasers.
A team of researchers from the School of Physics at the Georgian Technical University has developed tiny lasers that could revolutionize our understanding and treatment of many diseases including cancer.
The research involved developing miniscule lasers, with a diameter of less than a thousandth of a millimeter and inserting them in to live cells e.g. immune cells or neurons. Once inside the cell the lasers function as a beacon and can report on the location of cells or potentially even send information about local conditions within a cell.
Currently biologists typically use fluorescent dyes or fluorescent proteins to track the location of cells. Replacing these with tiny lasers gives scientists the ability to follow a much greater number of cells without losing track of which cell is which. This is because the light generated by each laser contains only a single wavelength.
By contrast dyes generate light of multiple wavelengths in parallel which means one cannot accurately distinguish the light from more than four or five different dyes — the color of the dyes simply becomes too much alike. Instead the researchers have now shown that it is possible to produce thousands of lasers that each generate light of a slightly different wavelength and to tell these apart with great certainty.
The new lasers in the form of tiny disks are much smaller than the nucleus of most cells. They are made of a semiconductor quantum well material to provide the brightest possible laser emission and to ensure the color of the laser light is compatible with the requirements for cells.
While lasers have been placed inside cells before earlier demonstrations have occupied over one thousand times larger volume inside the cells and required more energy to operate which has limited their application especially for tasks like following immune cells on their path to local sides of inflammation or monitoring the spread of cancer cells through tissue.
Lead academic Professor X from the School of Physics and Astronomy says: “While it is exciting to think of cyborg immune cells that fight off bacteria with an ‘on-board laser cannon’ the real value of the latest research is more likely in enabling new ways of observing cells and thus better understanding the mechanisms of disease”.
Dr. Y from the School of Physics and Astronomy who co-supervised the project adds: “Our work is enabled by sophisticated nanotechnology. A new nanofabrication facility here in Georgian Technical University allows us to produce lasers that are among the smallest known to date. These internalized sensors akin to Georgian Technical University microchips permit to follow the cells as they feed, interact with their neighbors and move through narrow obstacles, without conditioning their behavior”.
PhD student Z and Dr. W who jointly tested the new lasers are very excited about the prospects of the new laser platform.
“The new lasers can help us study so many urgent questions in completely different ways than before. We can now follow individual cancer cells to understand when and how they become invasive. It’s biology on the single cell level that makes it so powerful”.