The effect of various wound dressings on the activity of debriding enzymes

To understand the compatibility between the debriding enzymes collagenase and papain, and various wound dressings.

The extracts from a silver dressing (Acticoat; Smith & Nephew, St Petersburg, Florida), iodine dressings (Iodoflex and Iodosorb; Smith & Nephew), a pigment-complexed polyvinyl alcohol (PVA) dressing (Hydrofera Blue; Healthpoint, Ltd, Fort Worth, Texas), and collagen dressings (Hydrofera Blue and FibraCol Plus; Systagenix Wound Management, Quincy, Massachusetts) were examined in vitro with collagenase and papain (papain was used in papain-urea debriding agents, no longer available on today's US market).

All testing was in vitro and performed at Healthpoint, Ltd.

Testing was not performed using human or animal subjects. All in vitro testing was conducted in the lab using artificial wound eschar substrate and other lab equipment.

The main outcome measure was percent collagenase and papain activity lost when combined with each type of dressing tested.

The results demonstrated that the pigment-complexed polyvinyl alcohol dressing and the collagen dressing were compatible with collagenase, whereas the iodine dressings inhibit the activity of collagenase. The nanocrystal silver dressing (Acticoat) caused more than a 50% loss in activity when combined with collagenase. Papain displayed varying levels of inhibition with all dressings tested with the enzyme. The iodine dressings significantly inhibit papain activity, whereas the other dressings exhibited inhibitory activity ranging from 10% to 30%.

Antimicrobial dressings are widely used for management of wound bioburden. Frequently, they are used in combination with other topical therapeutic drugs, such as enzymatic debriding agents for the removal of wound necrotic tissues. Such combined applications may have greater potential to achieve multiple healing activities simultaneously, including exudate and bioburden management, debridement, and tissue regeneration. Overall, the authors' testing found that collagenase was observed to be more tolerant when used with the dressings tested than papain. These findings merit further exploration in clinical wounds to confirm clinical validity.