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Index: WOUNDS. 2012;24(9):242–253.

  Abstract: An important part of the wound healing process is the removal of necrotic tissue from a wound to promote healing. Enzymatic debridement is one of the widely used methods to accomplish this goal. Clostridium collagenase (C. collagenase) containing ointment is frequently used in clinics to debride wounds. In this work, the influence of metal salts and various types of surfactants on the enzymatic activity of C. collagenase is tested. The relationship between charge and size of metal ions and surfactant structure is explained in the context of enzyme inhibition. Commonly used wound care products, such as cleansers, dressings, antimicrobial formulations, and silver dressings are tested with C. collagenase. The results are discussed in terms of enzyme compatibility with such materials, and recommendations for use of wound care accessories in conjunction with the debriding enzyme are given, with the aim to help wound care providers make more educated choices towards accomplishing optimal therapy outcome.

Introduction

  Effective wound debridement has been widely used to remove necrotic tissue from a wound to promote healing. Necrotic tissue present in a wound bed is undesirable because it prolongs the inflammatory stage and may serve as a reservoir for bacterial growth, thus slowing the tissue regranulation necessary for wound repair.¹ It is increasingly well-recognized that removal of nonviable tissue from a wound² is an important step that may facilitate the healing process for a variety of wound types, especially burn wounds and various chronic wounds.^3-5 Wound debridement may be performed in several different ways: surgical, autolytic, enzymatic, and mechanical. Each of these has its own benefits and shortcomings, depending on the wound type and the condition of the patient.^6,7 Enzymatic debridement can provide an effective methodology for various chronic ulcers, especially in patient populations not amenable to surgical debridement.

  Currently, Collagenase Santyl® Ointment (Healthpoint Biotherapeutics, Fort Worth, TX) is the only Food and Drug Administration (FDA)-approved enzymatic debriding biological in the United States.⁸ The enzyme activly used in this drug is a bacterially derived collagenase from Clostridium histolyticum (C. collagenase). C. collagenase, a metalloproteinase with Zn2+ in the active site, contains 2 principal enzyme species: collagenase I (Col H, 116 kDa, predominantly b-sheet structure) and collagenase II (Col G, 124kDa, predominantly a helix structure). Both enzymes specifically attack collagen in wound necrotic tissue, which contains mostly the denatured collagens.⁹

  Frequently, the enzymatic debrider is used in conjunction with various wound dressings¹⁰ to achieve multiple treatment goals simultaneously, including infection control, pain control, and exudate management. Furthermore, wound cleansers are often used before or even alongside debriders to remove loosened tissue debris, bacteria, and other physicochemical contaminants that can seriously impede the wound healing process. Some dressings contain certain levels of metal elements (eg, silver) as principal bactericides, while wound cleansers rely on the cleaning power of various surfactants to remove the debris from the wound bed. The purpose of this work is to evaluate the influence of various metal salts and surfactants on C. collagenase enzymatic activity. Moreover, commercially available wound care accessories, such as cleansers, dressings, and antibacterial preparations, will also be tested for compatibility with the enzyme.