Effective Removal of Antimicrobial Resistant Bacteria from Chronic Wounds

Complications of aging and diabetes include the development of chronic venous leg ulcers, pressure ulcers and diabetic foot ulcers. Estimates of frequency and cost from routine NHS data concludes that chronic wounds have a prevalence of 6% and utilise at least 5.5% of the total NHS expenditure. However, with an ageing population and a significant increase in the incidence of type 2 diabetes, these figures will unquestionably increase. A chronic wound fails to heal in the standard time frame, resulting in a non-healing wound and is characterised by an increased incidence of bacterial biofilms, leading to persistent inflammation, with excessive proteolytic activity that prevents repair of the underlying tissue and resolution of the healing process.

Bacterial biofilms associated with chronic wounds represent multiple species of bacteria within extracellular polymeric substances, which create physical barriers to prevent antibiotic penetration and chemical buffering to attenuate antibiotic bactericidal efficacy. Therefore, the management options for chronic wounds can be complicated, debridement of compromised tissues, use of specialised dressings, and administration of broad and sometimes narrow spectrum of antibiotics. However, the success rates of the currently followed treatment options are still far from being satisfactory leading to the prolonged use of broad-spectrum antibiotics. Consequently, the potential for the rise of antimicrobial resistant (AMR) bacterial populations, and unresolved healing, which may lead to foot or lower limb amputation is high. Therefore, finding new alternatives for the treatment of bacteria that evoke inflammation and delay the wound healing process is of great importance.

This research project will develop a smart polymeric wound dressing that preferentially facilitates the attachment of bacteria associated with chronic wounds typically seen in elderly and/or diabetic patients over their adherence to skin. When the dressing is removed the bacterial populations will be extracted, reducing the level of infection. This in turn will help resolve the high level of inflammation in the wound, which will allow the tissue to progress through the normal sequential stages of wound healing.