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UM-Rolla
professor makes glass beads to fight diseases
BY BETHANY
HALFORD
Of the Post-Dispatch
08/12/2002
06:46 AM
At a
fraction of the width of a human hair, Delbert Day's glass beads don't amount
to much - physically speaking. But the tiny spheres could be biological
boulders - rolling over rheumatoid arthritis and crushing liver cancer from
inside the body.
Even though glass may seem too fragile to use in the body, Day says that its
versatility makes it superior to implants of metal or plastics.
The professor of ceramic engineering at the University of Missouri at Rolla
uses the body's natural chemicals to make medically useful glass. That way the body
doesn't recognize the material, called bioactive glass, as a foreign
object. It's essentially just window glass though - window glass that disappears.
"We don't want our window panes to dissolve. We don't want our drinking glass to dissolve,"
said Day. But the unique properties of bioactive glass allow it to do its
job and then be absorbed safely within the body.
Day and his colleagues use flame spraying to make the glass beads. The
technology works like an aerosol can of hairspray - only heated to 3,000
degrees. The red hot molten glass spews forth from the end of a flame in tiny
round droplets.
He recently filed two new patents - he holds 42 - for bioactive glass inventions.
Working with Gary Ehrhardt at the University of Missouri Research Reactor
Center in Columbia, Day patented radioactive glass beads that can be
injected into arthritic joints. Once there, Day said the glass "emits a type
of radiation that reduces the swelling and pain associated with rheumatoid
arthritis."
After delivering their radiation, the beads react with the body's fluids and
dissolve.
"Our work is to develop glass beads that do not let radioactivity escape
the joint," Day said.
The beads work like valet parking for the radiation - taking it to
inflammation's front door. At the same time, it keeps the radiation from
dangerously cruising elsewhere in the body.
Day reckons it will be years before arthritis sufferers find relief using his
glasses. He and Ehrhardt
began working on TheraSpheres - a treatment for inoperable primary liver
cancer - in 1984. The Food and Drug Administration didn't approve
TheraSpheres until 2000.
Using the valet parking idea, a doctor injects the TheraSpheres into the
artery that leads to the liver.
"The liver acts as a great big filter and the beads get caught,"
said Day. The tiny spheres, laced with radioactive yttrium-90, radiate out
"like millions of little suns in the liver."
"If you can confine a drug to the target site, then it's going to be most
effective." Day said that because the treatment is localized, doctors
can use TheraSpheres to deliver five to 10 times more radiation than
traditional therapy uses. Patients experience little or no side effects. The
treatment doesn't require them to be hospitalized.
"The concept is very appealing," said Dr. Jeff Geschwind, professor
of radiology at Johns Hopkins Kimmel Cancer Center in Baltimore. Johns
Hopkins is one of seven sites in the country using the therapy. St. Louis
University hopes to bring the treatment to this area.
Last year, Kim Cunningham learned that she had neuroendocrine tumors in her
liver. The 38-year-old physical therapy student's liver had doubled in size.
"It was way down by my belly button," she said. "At one point
it was really pushing everything out of the way."
When doctors showed her scans of the tumor, Cunningham saw "an enormous
7-centimeter hole - just a hole - where the cancer was."
Dr. David A. Van Echo at the University of Maryland Greenebaum Cancer Center
in Baltimore treated Cunningham with two courses of TheraSpheres.
While she is still undergoing other treatments for her cancer, Cunningham
said the TheraSpheres had a huge impact on her illness. "Now I can run
and it feels great," she said. "I am really getting away easy
compared to what I've seen a lot of people go through."
Reporter Bethany Halford:
E-mail: bhalford@post-dispatch.com
Phone: 314-340-8337
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