Topic Eight: Protease Modulators

Chronic wounds are characterised by a prolonged inflammatory phase. Integral to chronicity are elevated levels of tissue-degrading enzymes and matrix metalloprotease (MMPs) (Lobmann et al., 2002; Schultz & Cullen, 2017).

MMPs are a specific group of zinc-containing proteolytic enzymes. They play an important role in remodelling the extra-cellular matrix during healing in both degradation and regeneration and in supporting epithelisation. In normal wound healing, there is a balance between the clearing of damaged tissue and the building of new tissue (Martin, 2011).

Protease activity not only prolongs the inflammatory process but adversely affects cell migration, granulation tissue formation and wound contraction. TIMP (tissue inhibitors of MMP) are the natural inhibitors of MMPs. In normal wound healing, the levels of TIMPs and MMPs are balanced. Therefore, in chronic wounds, there is an imbalance of TIMPs and MMPs, which leads to an unstable extracellular matrix (Martin, 2011).

Mode of Action

A range of dressings have been developed that are able to interact with the wound and modulate the protease activity. The intentions of the dressings are to influence the wound environment and restore the balance of MMPs and TIMPs.

Indications for use

Indicated for the use with chronic, non-infected wounds such as:

• Diabetic foot ulcers
• Leg ulcers
• Pressure ulcers

In addition, to regulate the micro-environment of the wound, it must regulate the MMP imbalance, facilitate re-epithelialisation, promote wound closure and support faster healing of chronic wounds (Martin, 2011).

Contraindications

Collagen-based protease modulator dressings are generally contraindicated for dry wounds.

Refer to the manufacturer’s instructions for use.