Dress up and deliver

A new 'scaffold' dressing could improve healing, offering particular help in hernia repair and stomach surgery, writes Claire…

A new 'scaffold' dressing could improve healing, offering particular help in hernia repair and stomach surgery, writes Claire O'Connell

Sometimes elegant solutions can develop if they are given the right platform. Consider a wound dressing that acts as a scaffold and encourages the body's own cells to grow a protective layer over a cut. That's the goal of NUI Galway researcher Prof Abhay Pandit, whose team has developed a gauze-like mesh of biomaterials to help tissue repair.

The idea is to provide a matrix for cells to grow on and through, then eventually the scaffold degrades and melts away to be excreted naturally by the body, according to Prof Pandit, who is professor of biomedical engineering at NUIG.

The scaffold is a mesh of collagen and elastin, fibres that occur naturally around cells in the body. But just mixing the components together in a dish would not give the mechanical properties required to help wound repair, explains Prof Pandit.

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"So we went back to basic anatomy and asked: if we were to create a matrix like that, where do we look at?" he says. A researcher in his lab zoned in on hollow organs, because their walls contain a layer with mesh but no cells. This is an advantage when you want to avoid triggering an immune response, he explains.

"HE STUMBLED UPON the gallbladder and isolated this layer from the organ, and that's what our matrix is, it's from the gallbladder."

However, the Galway team found they could improve the mechanical properties of the natural collagen and elastin mesh by cross-linking the fibres, a move that also allows the researchers to tailor the matrix for different uses, he says.

"We can programme the properties of the scaffold by treating it in different ways," he says. "The more cross-links, the higher the mechanical properties of the matrix will be, but the slower the degradation profile. So we have programmability in the scaffold."

What sets this biomaterials scaffold apart from others is the strength and safety of the cross-links, according to Prof Pandit. "Most of the other products use much more toxic ways of cross-linking the substrate, but ours is benign," he says.

His team at the National Centre for Biomedical Engineering Science has recently looked at how their scaffold performs using various cell types in the lab and in pre-clinical tests. "The questions there are what is the degradation rate; what is the tissue response; are we getting inflammation; is there an immune response. It's those basic questions you are answering," says Prof Pandit, whose work is funded by Enterprise Ireland.

"And now we know the behaviour, so we are doing the functional studies. We are looking at hernia repair, where we can put this patch on a hernia and the muscle will grow on top of it. We are also looking at staple line reinforcement of internal wounds for stomach surgery."

In future the scaffold could carry added ingredients to coax cells to behave a certain way, but Prof Pandit believes that is some way down the line. "We realise that for commercial applications that may be too far-fetched. I don't think the industry or even the regulatory agencies are ready for something like that," he says, adding that the first generation product would be a simple gauze-like patch. "It's a platform and you can build from it."

Prof Pandit will today pitch his ideas on another platform: The Next Wave, an Enterprise Ireland event at University College Dublin that will showcase six innovative technologies arising from research in Irish universities.

The audience will include parties with an interest in commercialisation, including venture capitalists.

"I'm quite positive we will get a good response because it's a good story," says Prof Pandit of his tissue-repair scaffold. "We have come a long way and we are delighted by what we are seeing."