Bioburden: Normally defined as the number of bacteria living on a surface that has not been sterilized. The term is most often used in the context of bioburden testing, also known as microbial limit testing, which is a quality control test performed on medical devices and pharmaceutical products.

Biofilm: A complex microbial community containing bacteria and fungi. The microorganisms synthesize and secrete a protective matrix that attaches the biofilm firmly to a living or nonliving surface. The biofilm contributes to underlying wound infection, chronic inflammation, and delay in healing, and it is present in 80% to 90% of chronic wounds and 6% of acute wounds.

Cellular and/or tissue-based products: Engineered wound dressing products created to promote biological repair or regeneration of wound tissue by providing signaling, structure, or cellular elements with or without systems that contain living tissue or cells. These products actively promote healing by stimulating the patient’s own cells to regenerate healthy tissue. There are multiple options for these products, including: nonviable cells, tissue-based: human; viable human cells, cultured in vitro: animal substrate; viable human cells, cultured in vitro: synthetic substrate; and viable human cells, noncultured: intact tissue.

Chronic wound: A wound that has failed to progress toward healing in the expected time frame. Varying factors can cause a wound to stall, such as infection or a prolonged inflammatory phase. It is important to document the wound’s progress, any stalling factors, and the interventions put into place to restart the healing cascade.

Collagen: The most abundant protein in the human body. Collagen increases matrix metalloproteinases and organization of newly formed collagen fibers, thus promoting granulation formation. In wound healing, collagen attracts fibroblasts and encourages the deposition of new collagen to the wound bed. In wound care products, collagen is derived from bovine, equine, porcine, piscine, ovine, and/or avian sources.

Extracellular matrix: A 3-dimensional network that consists of collagen, enzymes, and glycoproteins and provides structural support to surrounding cells.

Matrix metalloproteinases (MMPs): A group of enzymes that break down the extracellular matrix and delay healing. They are found in excessive amounts in chronic wounds.

Proinflammatory cytokine: Immunoregulatory cytokine that favors inflammation. The net effect of an inflammatory response is determined by the balance between proinflammatory and anti-inflammatory cytokines.

Polyhexamethylene biguanide (PHMB): A synthetic polymer that is used as a broad-spectrum preservative and antimicrobial agent in skin care.

Sharp debridement: Debridement performed by using sharp instruments, including but not limited to scalpels, scissors, or curettes.