Cool technique for wounds
A DEAKIN University breakthrough that uses ice crystals to form porous silk scaffolds is offering hope that a way to improve wound healing could be available in the not-too-distant future.
Chronic wounds are most commonly found in the elderly, with about 25 per cent of residents in aged-care facilities suffering from a wound caused by injuries such as ulcers, tears or pressure sores.
Overall, chronic wounds are estimated to affect more than 433,000 Australians a year, at a cost of $2.6 billion to the Australian healthcare system annually.
A group of four leading fibre materials scientists at Deakin’s Institute for Frontier Materials has discovered that ice crystals can be used to create artificial scaffolds that accelerate the repair of damaged human tissues.
The team has successfully developed a way to grow and harvest these unique scaffolds, which could one day be used to promote cell growth and improve healing of chronic wounds.
The researchers found that ice crystals can be used to form a template for a scaffold, consisting of aligned nanofibres and interconnecting channels.
Dunking a solution of silk protein into liquid nitrogen triggers the rapid formation of aligned fine ice crystals, alongside aligned silk nanofibres.
After removing the fine ice crystals, a network of nanofibres is formed. In the next step, the scientists grow larger ice crystals along the nanofibres into the network. After the larger ice crystals are removed by freeze-drying, macro-channels are created.
Like guiding plant growth using a garden trellis, the resulting scaffold could be used to support and guide cells in the regeneration of tissues when placed on to a patient.
The scaffold is made of silk fibroin, a protein generated from silkworm silk fibres. It can be degraded and absorbed by the human body during the tissue regeneration process.
The IFM researchers, Dr Linpeng Fan, Associate Professor Jingliang Li, Dr Zengxiao Cai and Professor Xungai Wang, are enthusiastic about the potential of their research.
“This new scaffold could speed up the healing process significantly. There are several more stages of research and development to get to that stage, but we’re hopeful this could be on the market within the next five years,” said Dr Fan.
He said the breakthrough had created an artificial scaffold that was capable of mimicking the structure and function of a naturally occurring substance in which cells were embedded.
“Scaffolds formed by natural polymers such as proteins play crucial roles in tissue engineering, helping to induce tissue repair by undamaged cells at the site of an injury,” Dr Fan said. “An ideal scaffold should not only provide a three-dimensional environment and support, but also direct cell behaviours and functions by interacting with cells.”
Prof Li said the scaffold developed by the IFM team was uniquely suited for use in healing chronic wounds.
“What we’ve managed to do with this breakthrough is develop a scaffold no other technique, such as electrospinning or 3D printing, has ever been able to achieve,” he said.
Prof Wang said the strategy that had been developed allowed various kinds of active scaffolds to be developed that could imitate naturally occurring shapes and direct healthy cells to grow towards the target site, which was very important to accelerate the regeneration of damaged tissues.
“The aligned nanofibres on the channel walls can also play an important role in promoting cell capture and proliferation, as well as directing cell migration,” he said.
“Furthermore, the nanofibres and nanoparticles can be good carriers for the delivery of growth factors or drugs.”