Feb 14, 2003
Nanofibre 'bandage' could heal wounds
Scientists at Virginia Commonwealth University, US, have used electrospinning to make a nanofibre mat from fibrinogen, a soluble protein that is present in the blood. The mat could have applications as a wound dressing or tissue-engineering scaffold.
"If you were bleeding and a paramedic came up to you on the street, what would he do?" said Gary Bowlin of Virginia Commonwealth University. "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."
But the fibrinogen mat could stay on the wound, eventually being adsorbed by the body. When the body is cut, its clotting mechanism breaks down the naturally occurring fibrinogen in the bloodstream and converts it to fibrin. "Fibrin is the meshwork," said Bowlin. "It's like throwing a net over the clot that holds it together and keeps it from dissolving quickly."
The researchers made a 100 µm thick mat of fibrinogen fibres with an average diameter of 80 nm; natural fibrinogen fibres are typically 82-91 nm in diameter. "The key is that we're making these fibres at basically the same dimensions as you would find in a natural clot," added Bowlin. "So when the body sees it, it sees it as normal and it's going to promote normal things to happen."
To carry out the electrospinning process, the researchers forced a solution of fibrinogen through an electrically charged nozzle towards a stainless-steel target. The solution emerged from the nozzle in the form of a liquid jet. As the jet reached the target, the solvent evaporated and the liquid was transformed into dry fibres. By altering the concentration of the fibrinogen solution, the team also made batches of fibre with average diameters of 310 and 700 nm.
The scientists, who reported their work in Nano Letters, believe they may also be able to electrospin mats made of both fibrinogen and collagen fibres. That would give them the option of forming a variety of composite structures. They could also co-spin polymers with additives such as growth factors or antibiotics to tune the scaffold to grow selected cell types.
The university has licensed the technology to US company NanoMatrix.