Professor Russell Morris, from the University of St Andrews, has used an exciting development in chemical technology – metal-organic frameworks (MOFs) – to apply small, beneficial amounts of the gas, nitric oxide, to wounds safely in order speed up healing. He will receive his prize at a special event at the Royal Society today (5 December 2012). Nitric oxide is a simple gas molecule which in large amounts is significantly toxic; however in small amounts it has essential roles in the body, such as controlling blood pressure in the cardiovascular system and also in wound healing.
When a wound occurs in normal skin the body produces nitric oxide to fight infection through its antibacterial properties and then to signal the production of new blood vessels to increase blood flow to the damaged area. Unfortunately people who suffer from diabetes, or those who are elderly or obese often don’t produce enough nitric oxide naturally which can lead to poor wound healing. In bad cases, such as chronic wounds which do not heal, the affected limbs may need to be amputated.
Among chronic wounds the highest prevalence lays in the venous leg ulcer (VLU), diabetic foot/leg wound (DFU) and pressure ulcer (PU) categories. Estimates of annual VLU incidence in the US reach nearly 1 million. In 2010-11, the NHS in England spent an estimated £639 million–£662 million, 0.6–0.7% of its budget on diabetic foot ulceration and amputation. Patients with type I or II diabetes have a 1-4% annual chance of foot ulceration and a lifetime risk that may be as high as 25%. Estimates for the UK indicate that 15% of all diabetes patients develop DFUs and that 84% of lower leg amputations are caused by DFUs.
There is strong evidence that the addition of nitric oxide to wounds can be extremely beneficial in these situations. However because nitric oxide is a toxic gas there needs to be a method of applying small, beneficial amounts of gas safely to a wound.
The MOFs that Professor Morris is working on offer an opportunity to do just this. These solids are extremely porous and have a very large internal surface area and can store large quantities of gas safely. Professor Morris and his team are developing non toxic MOFs to be incorporated into wound dressings which deliver nitric oxide slowly and at levels which do not cause any toxic or inflammatory effects but show beneficial effect of improved wound healing.
Professor Russell Morris said of his work:
“The highly porous metal-organic frameworks act as miniature gas tanks, allowing us to deliver only safe and beneficial amounts of nitric oxide from something as easy to use as a wound dressing. This will transform how we can use this gas to help people with debilitating chronic wounds.”
Professor Morris will receive just under £200,000 from the Royal Society to develop the technology further so that it can be put into clinical trials. The Brian Mercer Award for Innovation is a scheme for scientists who wish to develop an already proven concept or prototype into a near-market product ready for commercial exploitation. Professor Morris has already benefited from Royal Society support including a University Research Fellowship (1998-2006), Wolfson Research Merit Award (2009-2010), the Brian Mercer Feasibility Award (2008) and a current Industry Fellowship