5.1 This guide provides definitions and a classification for CTPs, as well as definitions related to skin tissue, skin wounds and ulcers, wound healing physiology, wound covers, and related medical and surgical procedures. This guide is not intended to prescribe or limit the clinical uses of these products.

5.2 One objective of the current guide is to include the wide range of CTPs for which there is a rationale for benefit beyond that achievable with conventional wound coverings. Whether an individual CTP is capable of promoting wound healing must be determined by adequate evidence and is beyond the scope of this standard. Given that some of the materials used in dressings and skin substitutes (defined in ASTM Standard F2311) are the same as those used in CTPs, there has been confusion as to how to classify these products.

5.3 This guide is distinguished from ASTM Standard F2311, which defines terminology and provides classification by clinical use for products that can be substituted for tissue grafts of human or animal tissue in medical and surgical therapies of skin lesions. In contrast, this guide defines terminology for description of CTPs for skin wounds; CTPs are defined primarily by their composition. Neither guide establishes a correspondence between device structure and clinical function.

1.1 This guide defines terminology for description of cellular and/or tissue-based products (CTPs) for skin wounds. CTPs are defined primarily by their composition and comprise cells and/or the extracellular components of tissue. CTPs may contain cells (viable or nonviable), tissues, proteins, and other materials for which there is a rationale for benefit beyond that achievable with conventional wound coverings. CTPs may additionally include synthetic components. Whether an individual CTP is capable of promoting wound healing must be determined by adequate evidence and is beyond the scope of this standard.

1.2 This guide also describes a classification and nomenclature for CTPs based on their composition. This systematic nomenclature is not intended to be prescriptive for product labeling, and it describes only the most salient characteristics of these products; the actual biological and clinical functions can depend on characteristics not recognized in the nomenclature, and it should be understood that two products that can be described identically by the nomenclature should not be presumed to be identical or have the same clinical utility.

1.3 This guide defines CTP-related terminology in the context of skin wounds. However, this guide does not provide a correspondence between the CTP composition and its clinical use(s). More than one product may be suitable for each clinical use, and one product may have more than one clinical use.

1.4 This standard does not purport to address safety concerns with the use of CTPs. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.