A new product for debridement of chronic wounds, developed using biomimicry and evidence-based medicine

Chronic wounds are those that fail to progress through a normal, orderly, and timely sequence of healing processes.
Chronic wounds affect 1-2% of the population in developed countries. The NHS treated 1.6m patients with chronic wounds in 2017-18, costing £6.5bn (1); in addition to this formidable economic burden, such wounds have a devastating impact on patients' quality of life (2). Ageing populations, antibiotic resistance and the rise in conditions such as diabetes mean chronic wound prevalence is increasing (3,4). Effective debridement (the removal of debris and dead or infected tissue) is crucial for chronic wound healing; however, current debridement methods have significant limitations, being slow, invasive and painful or having adverse side-effects (5). To prevent health services being overwhelmed, and to improve the lives of patients, it is vital that new solutions are found to accelerate the healing of these wounds.

Biological debridement using live maggots is an effective solution, overcoming many of the above limitations (6,7).
However, reluctance of patients and the costs and complexity of rearing medical-grade disinfected maggots mean the full potential of this approach has not been realised (8). Working with healthcare institutions and leading professionals in the wound care community, SolasCure Ltd have identified the enzyme in maggot saliva that is key for wound debridement and have sequenced and cloned the gene responsible into yeast to enable its production. SolasCure have shown that this recombinant enzyme, Aurase is safe to use and demonstrated that when formulated as a gel, wound debridement could be achieved over a period of approx. 4 weeks (i.e. 12 applications dosed three times weekly). However, it would be preferable if even more rapid debridement (within 2-3 weeks, 6-9 applications) could be achieved. It would also be preferable if the wound gel only needed to be applied when routine wound dressing changes were being made, which is typically twice a week.

The work carried out by the University of Hertfordshire will test the release of Aurase from different wound formulations. The formulation characteristics affecting enzyme release will be investigated and the understanding gained used to design improved formulations that will improve clinical treatment. The new formulations will achieve this by releasing an increased amount of Aurase onto the wound surface so that rapid debridement of the wound is achieved and by providing a controlled delivery of the enzyme over 72 hours, ensuring that the product is effective over the whole period between dressing changes.