72 + 24 adults with >50% necrotic/slough/fibrin non-viable tissue on a hard to heal wound (venous leg ulcer, diabetic lower extremity ulcer or traumatic/ post operative wound) between 5 cm2 and 200 cm2 (surface area in stage 1) or 3 cm2 - 150 cm2 (in stage 2), will be enrolled into the study.