Human Cells Transformed into Tiny Lasers
The advance could someday help track the spread of diseases, such as cancer. Continue reading →
Living biological cells can now be turned into tiny lasers that emit light that can be used to track the spread of diseases, such as cancer.
Researchers Matjaz Humar and Seok Hyun Yun at Harvard Medical School uncovered three ways to turn human cells into functional lasers.
First, they injected cells with tiny oil droplets to form a cavity that could be filled with fluorescent dye. When an external pulse of light was directed at the droplet, the cells emitted light in a narrow beam.
Secondly, the team used polystyrene beads, which were ingested by a type of white blood cell, to carry out functions similar to the oil droplets.
In a third technique, pictured above, the scientists exploited fatty droplets that existed within living cells to emit a beam of light.
Humar told New Scientist that the process was "actually super-easy."
The first two methods were tested on humans, and the third method was tested using pig cells.
The new method could also make is much easier to distinguish between different cells.
Today, fluorescent dyes are commonly used to tag living cells and emit light, but they produce a broad range of wavelengths that can make it challenging to differentiate one tagged cell from another.
The new method of turning cells into tiny lasers makes it much easier to distinguish between tagged cells since lasers have a more narrow range of wavelengths.
In the future, scientists could potentially give every cell in the human body its own unique laser signature. This could help to track the spread of tumor cells, for example, or monitor how cells respond to inflammation.
The findings were published in the journal Nature Photonics.
Lasers may bring to mind military-grade weaponry or the pew-pew sounds of science fiction blasters, but powerful laser tech can be used for less destructive purposes. Scientists and engineers are now aiming lasers at persistent problems like air turbulence, inoperable tumors and drug addiction. Here's a look at the ways zapping something with a beam of light can actually help rather than hurt.
Scientists -- and super villains -- have long wanted to control the weather with technology. What once seemed like a wild dream has become possible in theory. In late 2013, the World Meteorological Organization conference in Geneva held a Laser, Weather and Climate conference where participants discussed controlling lightning and condensation with laser assists.
More recently researchers at the University of Florida and the University of Arizona surrounded one laser beam with another, a technique they think could help a high-energy beam go greater distances.
In 2010, neurosurgeons from Washington University were among the first in the United States to use a laser probe on brain tumors thought to be inoperable. The team, led by chief of neurosurgery Ralph G. Dacey Jr., employed the new MRI-guided probe from Monteris Medical to kill cancer cells deep in a patient’s brain, leaving the surrounding tissue intact. Last year the laser probe, called the NeuroBlate Thermal Therapy System, was cleared by the Food and Drug Administration.
Laser beams could be the key to getting hearts beating correctly, an alternative to current electrode-based pacemakers that can do damage to heart muscle over the long-term. In 2010, scientists from Case Western University and Vanderbilt University successfully paced a live quail embryo heart with light from an infrared laser.
While we don’t quite have human optical pacemakers yet, a team from the University College London recently made headway with a separate laser-based technique. They’re hoping to create an “optical pacemaker” for the diaphragm that could help patients with motor neuron diseases like ALS breathe independently.
Apira Science Inc.’s iGrow helmet to combat baldness may not look serious at first, but the company says this low-level laser therapy has been proven effective at stimulating cell activity around weak hair follicles. The helmet interior has red laser and LED light diodes that go to work in multiple weekly sessions over several months.
Apria points to an article in the journal Lasers in Surgery and Medicine that concluded low level laser therapy improved hair counts for men with alopecia compared to a placebo light-up helmet.
Could controlling addiction be as easy as flipping a switch? In 2013, scientists from the National Institutes of Health and the University of California were able to turn off compulsive behavior in rats through a combination of genetic engineering and laser light delivered through fiber optic cables. When they turned on a laser light in the brain region responsible for decision-making and impulse control, the compulsive cocaine seeking was gone, according to researcher Antonello Bonci.
While lasers were used for the study, techniques like noninvasive transcranial magnetic stimulation would probably be used for human trials.
A team from Leibniz University Hanover led by biosystems engineering professor Thomas Rath has been working on a way to eradicate pesky weeds with lasers. In 2012 he and his colleagues investigated mid-infrared range lasers as an alternative to herbicides.
A year later Leibniz University engineers shifted their focus and began studying the effects of near-infrared lasers on pests like aphids and whiteflies. They hope the right lase blast will safely kill the pests while leaving the host plants unaffected.
Last summer frequent fliers got a glimmer of hope for smoother travel. Researchers at the German Aerospace Center DLR’s Institute of Atmospheric Physics began testing technology that can detect turbulence, particularly the clear air kind that’s nearly impossible to predict. The device goes onboard a plane and emits short-wave ultraviolet laser radiation along the direction of flight, according to DLR. This reveals fluctuations in air density that indicate turbulence ahead. DRL has been testing the tech on flights in Europe with the goal of extending the detection distance to 20 miles.
Stanford University bioengineering, psychiatry and behavioral science professor Karl Deisseroth is a pioneer in using a technique called optogenetics, which involves genetically modifying neurons so they make a light-sensitive protein. Those cells can then be turned on or off with laser-based light.
Recently a group from University College London led by neurobiologist Linda Greensmith used optogenetics on paralyzed mice. Her group grafted genetically engineered motor neurons onto severed nerves in mice legs. Shining blue light on them restored nerve connectivity, reversing the paralysis.