Development of a porcine hard-to-heal wound model: evaluation of a bromelain-based enzymatic debriding agent.

Abstract

We describe the development of a novel porcine eschar model and compare the debridement efficacy of various concentrations of a novel bromelain-based enzymatic agent with collagenase. Full thickness excisional wounds were created on pigs and injected intradermally with various doses of doxorubicin. Wounds were monitored for a period of 46 days for the development of eschar and wound closure. After determining the optimal concentration and dose of doxorubicin resulting in non-healing eschars, these conditions were used to create additional wounds on another set of animals. The resulting eschars were treated with various concentrations of a novel bromelain-based enzymatic agent (EscharEx-02) or collagenase. The primary endpoint was greater than 95% removal of the central eschar. Consistent eschars composed of two distinct areas (a central area of exudate and slough representing the hard-to-heal wound bed, and a peripheral area of full-thickness mummified necrosis) were seen after injection of doxorubicin (0.5 ml/cm2 of stock solution 0.75mg/ml) at one and six days after wound creation. Complete removal of the central eschar was achieved in all wounds after five and eight treatments with 5% and 2% EscharEx-02 respectively. Complete removal of the central eschar with collagenase was achieved in 0% and 82% of the wounds after 10 and 16 treatments respectively. We describe a porcine model for creating eschars similar to hard-to-heal wounds in humans. A novel bromelain-based enzymatic debridement agent was more effective than a commercially available collagenase in removing eschars in this wound model.