Collagen plays a key role in each phase of wound healing. As a major extracellular matrix (ECM) protein, collagen is the most abundant protein in humans, contributing 25% of total protein mass and ~80% of the skin’s dry weight. Collagen acts as structural scaffold in tissues due to its stiff, triple-stranded helical structure; collagen 1, 2, and 3 are the main types found in connective tissue.1
Structurally, collagen is a natural substrate for cellular attachment, proliferation, and differentiation. Functionally, it is chemotactic and modulates cellular responses. Xenogenic dermal matrices have been developed from a variety of sources. Polymers such as hyaluronic acid, fibrinogen, heparin sulfate, laminin, and collagen (all components of natural ECMs) often are preserved or combined. These biomaterials are nonimmunogenic (unlike epidermis or vasculature), biocompatible, and nontoxic to tissues. They stimulate and recruit specific cells, enhancing the healing cascade.1,2
Collagen dressings usually are formulated with bovine, avian, or porcine collagen; rarer types include equine and piscine. Collagen dressings are available as sheets, pads, gels, paste, and powder and can be combined with antimicrobial agents, oxidized regenerated cellulose, or silicone. Numerous indications for collagen wound dressings include pressure injuries, second-degree burns, surgical and traumatic wounds, abrasions, and donor sites; contraindications include third-degree burns and wounds with dry eschar. Various collagen-based products have been used in pediatric wounds.