Bioengineered
Bandages That Do Not Need Changing Could Reduce Pain, Speed Healing
ARLINGTON, Va., Sept. 25, 2003 -- A bioengineered bandage developed
at Virginia Commonwealth University (VCU) would never have to be removed,
so it could stop bleeding, speed healing, and eliminate the pain and
reinjury caused by changing a conventional wound dressing.
The bandage, with the soft suppleness of a flannel shirt, is spun from
fibrinogen, a substance in the bloodstream that naturally collects around
blood clots to stablize the coagulating blood and initiate wound healing.
The bandage would jump-start the healing process with a strong layer
of fibrinogen fibers (fibrin) that would stabilize the wound and provide
a protective barrier. As the wound repaired itself, the bandage would
dissolve naturally.
"If you were bleeding and a paramedic came up to you on the street,
what would he do?" said Whitaker investigator Gary Bowlin, Ph.D.,
associate professor of biomedical engineering at VCU. "He'd probably
whip out a gauze, slap it on and hold pressure on it. When you get to
the hospital, they're going to rip that gauze off and start the bleeding
all over again."
The technology underlying Bowlin's bandage was descriped in the Feb.
12 edition of the journal Nano Letters. The novel bandage could
be used for anything from a minor cut to a life-threatening battlefield
wound. The university has licensed the technology to NanoMatrix, Inc.,
for potential commercial development.
The bioengineered bandage is a mat of very tiny fibrin filaments that
form a spaghetti-like mesh, a fabric that can be used to cover an injury
site to initiate clotting and promote wound healing and tissue regeneration.
To produce the mesh, researchers start with a high concentration of
fibrinogen dissolved in a solution with an attached nozzle aimed at
a metal target. A strong electrical field pulls the solution out of
the nozzle and toward the target. As the solution passes through the
electrical field, the liquid evaporates, leaving the fibrinogen fibers
to collect into a fabric on the metal surface. The fabrication process
is called electrospinning.
"The key is making the fibers at basically the same dimensions
you would find in a natural blood clot," Bowlin said. "So
the body sees it as normal and is going to promote normal things to
happen."
Fibrinogen fibers occur in the body at diameters between 82 and 91
nanometers. Bowlin's bandage material has fibrinogen of about 80 nanometers.
By comparison, the average human hair is about 100,000 nanometers in
diameter.
Bowlin's group has pioneered the electrospinning of nano-and micro-meter
fibrous structures, or scaffolds, of natural proteins, including collagn
types I, II and III, as well as elastin and fibrinogen for tissue engineering
scaffolds and wound repair products. Some examples include using electrospinning
to make synthetic blood vessels from collagens, elastin, and cartilage.
Bowlin's electrospinning and vascular tissue engineering work has been
supported by a Whitaker Foundation Biomedical Engineering Research Grant.
Contact:
Frank Blanchard, The Whitaker
Foundation
Gary Bowlin, Virginia Commonwealth
University
|