Chronic ulcers are debilitating wounds that can require many months or years of treatment. Their prevalence is growing, particularly in developed countries, due to the rise of diabetes and an increasingly aged population. Each year approximately 12 million people  will suffer from chronic wounds caused by diabetes, circulatory problems and other conditions.

The most commonly affected areas are the legs and feet due to vascular problems and additionally the sacral area as a result of pressure and/or shear. These hard-to-heal chronic wounds have a significant impact on patient morbidity. This leads to a high cost of care as severe cases are bed-ridden (estimated £3 billion annual cost to NHS) The key indicators of treatment efficacy are wound size, shape and colour. Typical treatment options are compression bandage therapy, vacuum-assisted closure (VAC^®) therapy, and surgical intervention - diabetes-related wounds are the leading cause for amputation in adults.