A fish parasite with a needle-like nose that pierces
the intestines of its host has inspired a revolutionary medical invention that
could replace surgical staples now used to hold skin grafts in place and close
serious wounds.
Researchers at Brigham and Women’s Hospital in
Boston, Massachusetts, led by biomedical engineer Jeffrey Karp, say they saw a
need for an improved medical adhesive and looked to nature for ideas.
“When we started looking into the parasite
literature, we quickly stumbled upon worms and, in particular, this
spiny-headed worm that has a needle-like proboscis [nose] that inserts in the
intestine of fish ... and only the needles swell, so it kind of mechanically
locks into place," said Karp, describing a freshwater-fish parasite called
Pomphorhynchus laevis, whose swelling and locking needle-nose design gave his
team a model for the new and improved surgical bandage with unique adhesive
properties.
Karp's prototype, a microneedle-lined bandage that
plumps up when exposed to water, locks painlessly into the patient's subdermal
tissue and adheres 3-and-a-half times more strongly than any clinical bandage
now in use.
The elongated microneedle tips, made with a rigid
plastic core, attach to stiff plastic inner and outer layers of highly
absorbent material that is similar to the inside of a disposable diaper. When
wet, the needles form a mechanical bond with the tissue.
The microneedle patch is also designed to eliminate
two specific problems with surgery involving skin-grafts.
According to Karp, who consulted with Dr. Bo
Pomahac, head of face transplant surgery at Brigham and Women’s, when
conventional staples hold skin grafts in place, they can produce holes 2-to-3
times larger than the width of the staple itself, allowing for potentially
harmful bacterial infections. The grafts, Karp says, are also susceptible to
filling with accumulated fluids, which can prevent healing.
“Instead of using staples," Karp said, "we
would apply a microneedle patch directly on top of the skin graft that will
push down to the underlying tissue and essentially lock that graft in
place."
Karp also envisions impregnating microneedle patches
with antibiotics and other drugs that would infuse slowly into wounds, helping
to keep them clean and quick-healing. Researchers are attempting to develop a
microneedle patch that can be used to help seal, and heal, internal organs
following surgery.
When it comes to removing the bandage, Karp doesn’t
think it would hurt more than pulling out surgical staples, which penetrate
skin more deeply than the microneedles on the new bandage patch.
The work by Karp and colleagues was funded in part
by the National Institutes of Health. An article describing a new micro-needle
surgical bandage is published in Nature Communications.
Sources :
http://www.voanews.com/content/needle-nose-parasite-health-brief-surgical-bandage-nature-communications/1645132.html
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