A MAT of polymer fibres designed to help wounds heal could spell the end for
traditional wound dressings, say British scientists. The fine web of fibres,
which is sprayed on, lets wounds heal by encouraging the formation of a strong
skin structure rather than weaker scar tissue.
When skin is punctured, the damage often destroys the weave-like structure of
collagen that gives skin its strength. But when the body tries to patch up the
wound, an evolutionary legacy means it acts in haste: in ancient times, if
people鈥檚 wounds did not heal quickly, they were likely to die. So instead of
rebuilding the complex collagen weave as before, the body creates a quick fix by
producing thin, aligned strips of collagen. When skin cells grow on this, they
produce the pale, less flexible material we know as scar tissue, rather than
normal skin.
Now Electrosols, a biotechnology company based in Haslemere, Surrey, has
developed a spray it believes could help wounds heal without scarring. The spray
produces a fine web of biodegradable polymer fibres that collagen-making cells
called fibroblasts can grow on. As more and more fibroblasts grow on the polymer
webbing, they produce a regular collagen structure, much like that in normal
skin. Electrosols researcher Ron Coffee believes that controlling the formation
of collagen in this way will lead to normal skin growth instead of scarring.
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To make the spray, Coffee mixes ethanol and a biodegradable
polymer鈥攕uch as polylactic acid鈥攊n a small semiconducting container,
and then gives it an electric charge by putting an electric field across the
container. Because the wound is at a far lower electrical potential than the
polymer, the solution is attracted to the skin surface and flies out through
tiny nozzles, producing fine, light fibres, each of them 5 micrometres in
diameter. The fibres have the same charge so they repel each other, making them
regularly spaced.
鈥淲hat you get is like a spider鈥檚 web,鈥� says Coffee, who is currently
developing a hand-held version of the spray. It looks like a fat pen about 2.5
centimetres across and about 15 centimetres long, and could be used by
paramedics or kept in first-aid kits, he says. But other researchers are more
cautious about the spray鈥檚 prospects.
鈥淭his initial polymer fibre mat wouldn鈥檛 necessarily have any bearing on the
final scar. Collagen is organised and reorganised continuously, and that鈥檚
governed by a whole range of things,鈥� says Bruce Martin, a reconstructive
surgeon at the University of Florida. 鈥淭his sounds very sexy, but I wouldn鈥檛 put
any great faith in it until I鈥檇 seen it work in animal and human trials,鈥� he
says.
