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A dime-sized biological laser developed by the
US Department of Energy detects cancer cells in seconds. While still in
the developmental stage, the device should assist surgeons in cutting
away malignant tissue while minimizing the amount of healthy tissue removed.
The instrument can quickly identify a cell population that has abnormal
protein content, as do tumor cells, by passing only a few hundred cells
-- a billionth of a liter -- through our device. In the "smart scalpel,"
cells are pumped through channels on the glass surface of the device.
Cancer cells with their increased amount of protein have increased density,
which changes the speed of the laser light passing through them.. The
device contains a microscopic spectrometer that analyzes protein density
in a cell and a tiny vacuum that sucks cells through microchip-connected
sensors for analysis during surgery. A graph on a laptop computer registers
the change.
The device came from compound semiconductor research
done at Sandia National Laboratories in Albuquerque, New Mexico, over
the last two decades. The research aimed to develop new light sources
for semiconductor materials that could be efficient and very small. That
technology led to the development of vertical-cavity surface emitting
lasers, which are the primary laser source for fiber-optic communications.
The idea developed when the researchers realized that they could analyze
human cells in one of these microcavity lasers by flowing cells through
the laser and making them become part of the lasing process. The device
has the potential to analyze up to 100,000 cells per second in real time,
five times faster than any other current method. Surgeons can quickly
see when blood pumped from the incision has been cleared of cancerous
cells. The "smart scalpel" is expected to cost between $10,000
and $50,000. By comparison, current flow cytometers cost $100,000 or more.
The time frame will be probably within the next 2 years to actually develop
some prototypes and get them tested in clinical settings.
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