[extropy-chat] plasma vs microorganisms

Damien Broderick thespike at satx.rr.com
Sun Oct 16 01:02:56 UTC 2005

from The Virginian-Pilot - Hampton Roads, Virginia, USA


October 15, 2005

ODU Pioneer Refines Healing Power Of Plasma

By Philip Walzer

Old Dominion University researcher Mounir Laroussi,
an associate professor of electrical and computer
engineering, has developed a "plasma pencil,"

The pencil, a hand-held cylinder 5 inches long and one inch in
diameter, passed its first test: It can kill E. coli bacteria
but leaves skin cells unscathed.

"When we got this to work," Laroussi said this week, "we knew we
were sitting on something really special."

He says this is just the beginning. The device, he hopes, will
do even more: cleansing and healing wounds, treating dental
plaque, even killing cancer tumors without damaging the
surrounding tissue.

Like the whirling electrons and ions that Laroussi has studied
for nearly 15 years, scientists have been buzzing since his
paper was published last month in the journal Applied Physics
Letters .

His progress has been reported on Web sites such as
<http://www.nature.com>www.nature.com and 
<http://www.physicsweb.org>www.physicsweb.org .

A plasma researcher in New Mexico calls Laroussi a pioneer in
the field.

"It's really the first demonstration of this technology that is
embodied in a practical manner," said Edl Schamiloglu , a
professor of electrical and computer engineering at the
University of New Mexico.

"In general," said another engineering professor, George Collins
of Colorado State, "his plasma work is world-class and full of
wonderful new innovations that are advancing the state of the

Its benefits, Laroussi said, have been exploited in such items
as fluorescent lights and semiconductor chips.

"We wanted to push plasma where it hasn't been before, which is
biotechnology," he said.

First, he needed to cool it off. In its normal state, at
hundreds of degrees Celsius, the plasma could burn away the good
with the bad.

So he brought it down to room temperature. That way, it can kill
the bacteria. But it doesn't harm healthy cells.

Laroussi proved the point at his lab this week.

He turned on the power for the pencil. A narrow, 2-inch-long
purple beam =96 Laroussi calls it a "plume" =96 shot out of it. He
brought it across the hands of two visitors.

Nothing happened. No singed flesh.

He's done this with hundreds of others. The first guinea pig was
Laroussi himself.

Of course, he wasn't scared. "I know what I have," he said.

Schamiloglu , the New Mexico professor, said the pencil improves
upon two previous inventions in plasma research.

One was a "plasma torch." It was too unwieldy, he said. And,
running on uncooled plasma, it could get too hot to handle.

The other was a "plasma needle" the size of a syringe. Much
easier to maneuver. But also prone to pricking the fingers of
even the most scrupulous technician.

"The plasma pencil represents a good compromise," Schamiloglu
said. "It's always satisfying to see something practical emerge
from basic research in universities."

Laroussi has received nearly half a million dollars in federal
grants for his work. His spacious lab is on the fifth floor of
the Norfolk Public Health Center on Brambleton Avenue, off
Colley Avenue. The lab is part of the Frank Reidy Research
Center for Bioelectrics , a partnership between Old Dominion and
Eastern Virginia Medical School.

Laroussi has collaborated with a postdoctoral research
associate, Xinpei Lu , and he has begun working with other ODU
professors in the areas of biology, oceanography and dental

One of them, Wayne Hynes , an associate professor of biological
sciences, also holds high hopes.

"If it works and doesn't do any tissue damage," Hynes said, "it
would potentially be able to kill the organisms associated with
plaque and therefore decrease tooth decay and gingivitis."

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