Funding for bioactive polymers in wound healing

The development of nano-sized microcapsules and bioactive bandages to assist in the delivery of the synthetic growth factor complex, VitroGro, is one of 251 projects to be funded in the latest round of the Australian Research Council's (ARC) Linkage Projects scheme.

Prof Andrew Whittaker and Assoc Prof Justin Cooper-White, at the University of Queensland, Dr Edeline Wentrup-Byrne and Dr J Malda from the Queensland University of Technology (QUT), and Tissue Therapies (ASX:TIS), a Brisbane based company set up in 2002 to commercialise the outcomes of research in tissue culture and repair from the QUT, will receive AUD$590,000 over four years to focus on developing methods for the delivery of VitroGro in its active form to wounds.

"We are looking at a combination of proven and cutting-edge technology," said Dr Steven Mercer, CEO of Tissue Therapies. "The idea is to take our cell biology technology and combine it with the nanotechnology intellectual property of the research group at the University of Queensland."

Tissue Therapies holds the worldwide rights to commercialisation for VitroGro, which is currently available as a research reagent for mammalian cell culture.

VitroGro is a complex of vitronectin, an extracellular matrix protein that is important in wound healing, and insulin growth factors -- and it is free of animal products. It can potentially deliver any growth factors that form a macromolecular complex with vitronectin and/or growth factor binding proteins to cells.

The researchers at UQ have developed a technique for microencapsulation, which would be used to protect VitroGro from the external environment and help maintain its bioactivity over time. Like all proteins, VitroGro needs care in handling, is sensitive to temperature and environmental factors, such as enzymes (proteases). "The microencapsulation involves standard tiny spheres with a known rate of dissolving that gives the ability to deliver VitroGro over a long time," explained Mercer. "Ideally you want to leave a dressing on for as long as you can, but this is technically and biologically challenging as you don't want to get infection."

The researchers at QUT will be focusing on a hydrogel matrix as a way of delivering VitroGro to chronic wounds, such as diabetic or venous ulcers.

"Hydrogels are friendly wound dressings," said Prof Graeme George, who will soon be returning to his specialty of polymer science research after seven years as Dean of Science at QUT. "They are cool to the touch, contain a lot of water and are good for the delivery of proteins as well.

"There is the problem of enzyme activity in chronic wounds," he said, "and diabetics have poor vascularisation and therefore lack growth factors to help close the wound over and re-epithelialise. There is a nasty feedback loop that gets set up and the wound never gets a chance to heal."

The hydrogel, which George described as an "intelligent bandage", neutralises the proteases in chronic wounds that feed this feedback loop, and then delivers VitroGro, which helps promote wound healing.

Mercer said they would also be looking at superficial versus deep chronic wounds and the biological differences between these as they may need different treatments.

The government will provide AUD$60.4 million for research in the lastest round of ARC linkage grants, and industry and other partner organisations have pledged up to AUD$92.6 million for the projects.

For more information go to: ARC linkage grants