1、Designation: F2311 08Standard Guide forClassification of Therapeutic Skin Substitutes1This standard is issued under the fixed designation F2311; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in
2、 parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide defines terminology and provides classifica-tion for products that can be substituted for tissue grafts ofhuman or animal tissue in m
3、edical and surgical therapies ofskin lesions.1.2 This guide provides a classification method for skinsubstitutes by comparing their clinical uses with those ofconventional tissue grafts. However, skin substitutes may alsohave equivalent, superior, or inferior clinical properties incomparison to conv
4、entional tissue grafts. Clinical classificationis independent of the materials and technology used to make askin substitute, or whether its components include human oranimal tissue or other biological or non-biological materials.1.3 This guide also describes a nomenclature for systematicdescription
5、of the technologies and components of skin substi-tutes that is independent of their clinical utilities. This system-atic nomenclature is not intended to be prescriptive for productlabeling, and it describes only the most salient characteristicsof skin substitutes; the actual biological and clinical
6、 functionsof skin substitutes can depend on characteristics not recognizedin the nomenclature, and it should be understood that twoproducts that can be described identically by the nomenclatureshould not be presumed to be identical or have the sameclinical utility.1.4 This guide does not provide a c
7、orrespondence betweenthe skin substitute composition and the clinical classification.Also, more than one product may be suitable for each clinicaluse, and one product may have more than one clinical use.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with
8、its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F2027 Guide for Characterization and Testing of Raw orStarting Biomat
9、erials for Tissue-Engineered MedicalProductsF2150 Guide for Characterization and Testing of Biomate-rial Scaffolds Used in Tissue-Engineered Medical Prod-uctsF2210 Guide for Processing Cells, Tissues, and Organs forUse in Tissue Engineered Medical ProductsF2312 Terminology Relating to Tissue Enginee
10、red MedicalProducts2.2 Other Reference:Dorlands Illustrated Medical Dictionary, 29th Ed., W. B.Saunders Company, Philadelphia, 2000.3. Terminology3.1 Skin Tissue Definitions:3.1.1 dermal, adjpertaining to the dermis. Dorlands3.1.1.1 DiscussionIn this guide, to avoid confusion, “der-mal” is preferred
11、 to be used to refer only to a patients existingor regenerated tissue and not to dermal tissue when used as acomponent of a skin substitute. Exceptions are “dermal au-tograft” and “dermal autograft substitute.”3.1.2 dermis, nthe layer of the skin deep to the epidermis,consisting of a dense bed of va
12、scular connective tissue.Dorlands3.1.3 epidermal, adjpertaining to or resemblingepidermis. Dorlands3.1.3.1 DiscussionIn this guide, to avoid confusion, “epi-dermal” is used to refer only to the patients existing orregenerated tissue and not to epidermal tissue used as acomponent of a skin substitute
13、. Exceptions are “epidermalautograft” and “epidermal autograft substitute.”3.1.4 epidermis, nthe outermost and nonvascular layer ofthe skin. Dorlands1This guide is under the jurisdiction of ASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of Subcommitt
14、eeF04.41 on Classification and Terminology for TEMPs.Current edition approved Oct. 1, 2008. Published November 2008. Originallyapproved in 2003. Last previous edition approved in 2006 as F2311 06. DOI:10.1520/F2311-08.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact AS
15、TM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesNOTICE: This standard has eith
16、er been superseded and replaced by a new version or withdrawn.Contact ASTM International (www.astm.org) for the latest information13.1.5 skin, nthe outer integument or covering of the body,consisting of the dermis and the epidermis, and resting uponthe subcutaneous tissues. F23123.1.6 tissue, nan ag
17、gregation of similarly specialized cellsunited in the performance of a particular function. In general,a tissue contains an extracellular matrix, in addition to special-ized cells. F23123.2 Skin Wound and Ulcer Definitions:3.2.1 excised skin wound, na full or deep partial thicknessopen skin wound th
18、at has been created by surgery and that isfree of foreign matter, necrotic and devitalized tissue, andmicrobial contamination, has no punctuate bleeding, and iscapable of engrafting a skin autograft. In addition, an excisedskin wound should have a suitable contour such that the skingraft or skin gra
19、ft substitute can adhere (such as by capillaryattractive force) without significant air or fluid pockets betweenit and the underlying viable tissue.3.2.2 full-thickness skin wound, na skin wound with theloss of epidermis, and all of the dermis or at least the depth ofdermis that includes most or all
20、 sources of epidermal cells fromepidermal adnexae (glands and follicles). F23123.2.3 lesion, nany pathological or traumatic discontinuityof tissue or loss of function of a part. In this guide, “skinlesion” is intended to encompass skin wounds and skin ulcers.F23123.2.4 open wound, na wound that comm
21、unicates with theatmosphere by direct exposure F23123.2.5 partial thickness skin wound, na skin wound withthe loss of the epidermis and part of the dermis, but retaininga layer of viable dermal tissue that includes the sources ofepidermal cells from which the wound can heal spontaneouslyby epidermal
22、 tissue regeneration. F23123.2.6 ulcer, na local defect, or excavation of the surface ofan organ or tissue, which is produced by the sloughing ofinflammatory necrotic tissue. F23123.2.6.1 decubitus ulcer, nan ulceration caused by pro-longed pressure allowed to lie still in bed for a long period ofti
23、me. Also known as decubital ulcer, pressure sore, bed sore.Dorlands3.2.6.2 diabetic foot ulcers, nan ulcer, usually of the lowerextremities, associated with diabetes mellitus. Dorlands3.2.6.3 venous stasis ulcer, nulceration due to venousstasis or insufficiency. Also know as stasis ulcer. Dorlands3.
24、2.7 wound, nan injury or damage, usually restricted tothose caused by physical means with disruption of the normalcontinuity of structures. Called also injury and trauma. F23123.2.7.1 DiscussionIn this guide, skin wounds includethose caused by trauma, surgical incision, or surgical excision;skin les
25、ion is the most general term, encompassing both skinulcers and skin wounds. This guide makes no distinctionamong different types of ulcers (for example, decubitus ulcers,diabetic ulcers, venous stasis ulcers) which are a result ofdiffering pathologies or conditions and for which differentprocedures
26、and different types of skin substitute may beappropriate.3.3 Wound Healing Physiology Definitions:3.3.1 DiscussionIn surgical wound closure, an importantdistinction is made according to whether the surgeon expectsthe healing to be accomplished by granulation tissue. Thisdistinction is made because i
27、n the normal physiology of woundhealing, granulation tissue matures into scar with woundcontracture, which is an undesirable outcome (see 6.3.1).Wound closure “by approximating the wound edges or per-forming a skin autograft” is “healing by first intention,” andwound closure by “allowing spontaneous
28、 healing from theedges” is “healing by second intention.”3.3.2 devitalized, ndeprived of vitality or life. Dorlands3.3.3 engraftment, nincorporation of grafted tissue intothe body of the host. F23123.3.4 graft take, nengraftment. F23123.3.5 granulations, ngranulation tissue.3.3.6 granulation tissue,
29、 nthe newly formed vasculartissue normally produced in the healing of wounds of softtissue and ultimately forming the cicatrix scar; it consists ofsmall, translucent, red, nodular masses or granulations thathave a velvety appearance. F23123.3.7 heal, vto restore wounded parts or to make healthy.F231
30、23.3.8 healing, nthe restoration of integrity to injuredtissue. F23123.3.9 healing by first intention, nhealing in which union orrestoration of continuity occurs directly without intervention ofgranulations. F23123.3.10 healing by second intention, nunion by closure of awound with granulations which
31、 form from the base and bothsides toward the surface of the wound. F23123.3.11 hypercatabolism, nabnormally increasedcatabolism. Dorlands3.3.12 necrotic, ncharacterized by the sum of the morpho-logical changes indicative of cell death and caused by theprogressive degradative action of enzymes. Dorla
32、nds3.3.13 primary healing, nhealing by first intention.3.3.14 primary wound closure, nwound closure by ap-proximating wound edges or performing a skin graft (healingby first intention).3.3.15 scar, nfibrous tissue replacing normal tissues de-stroyed by injury or disease. F23123.3.16 secondary healin
33、g, nhealing by second intention.3.3.17 secondary wound closure, nwound closure forhealing by second intention.3.3.18 skin replacement, nthe permanent replacement oflost or diseased skin with healthy skin.3.3.19 tissue regeneration, nhealing in which lost tissue isreplaced by proliferation of cells,
34、which reconstruct the normalarchitecture. F23123.3.20 tissue repair, nhealing in which lost tissue isreplaced by a fibrous scar, which is produced from granulationtissue. F2312F2311 0823.3.21 wound closure, nthe provision of an epithelialcover over a wound. It can be accomplished by approximatingwou
35、nd edges, performing a skin graft, or allowing spontaneoushealing from the edges. F23123.3.22 wound closure immediate physiological response,nan immediate restoration of some of the physiologicalfunctions of skin by a skin graft or skin substitute that isdemonstrated by an immediate reduction in wou
36、ndinflammation, pain, and fluid loss. Granulation tissue is notformed and wound contraction does not occur. In the case of alarge wound, the open wound systemic physiological responseis also reduced.3.3.23 wound contraction, nthe shrinkage and spontane-ous closure of open skin wounds. F23123.3.24 wo
37、und contracture, na condition of fixed highresistance to passive stretch of muscle, skin or joints resultingfrom fibrosis and scarring of the skin or the tissues supportingthe muscles or the joints, or both.3.3.24.1 DiscussionThis definition is a modification ofDorlands definition of contracture, “a
38、 condition of fixed highresistance to passive stretch of muscle, resulting from fibrosisof the tissues supporting the muscles or the joints, or disordersof the muscle fibers,” because that definition does not addressfibrosis and scarring in skin. F23123.3.25 wound inflammation, na localized protecti
39、ve re-sponse elicited by injury or destruction of tissues, which servesto destroy, dilute, or wall off (sequester) both the injuriousagent and the injured tissue. It is characterized in the acuteform by the classical signs of pain (dolor), heat (calor) redness(rubor), swelling (tumor), and loss of f
40、unction (functio laesa).Histologically, it involves a complex series of events, includingdilation of arterioles, capillaries, and venules, with increasedpermeability and blood flow; exudation of fluids, includingplasma proteins; and leukocytic migration into the inflamma-tory focus. F23123.4 Graft D
41、efinitions:3.4.1 allograft, na graft of tissue between individuals ofthe same species but of disparate genotype. Called alsoallogeneic graft and homograft.3F23123.4.2 autograft, na graft of tissue derived from anothersite in or on the body of the organism receiving it. F23123.4.3 conventional graft,
42、 nfresh or frozen graft tissue, nototherwise processed.3.4.4 dermal autograft, na skin autograft from whichepidermis and subcutaneous fat have been removed; usedinstead of fascia4in various plastic surgery procedures.F23123.4.5 donor, na living or deceased organism who is thesource of cells or tissu
43、es, or both, for research or furtherprocessing for transplantation in accordance with establishedmedical criteria and procedures. F22103.4.6 epidermal autograft, nan autograft consisting pri-marily of epidermal tissue, including keratinocyte stem cells,but with little dermal tissue.5F23123.4.7 full
44、thickness skin autograft, na skin autograftconsisting of the epidermis and the full thickness of the dermis.F23123.4.8 graft, nany tissue or organ for implantation ortransplantation. F23123.4.9 implantation, nthe procedure of inserting materialssuch as a cell(s), tissue(s), or organ(s) for therapeut
45、ic purposes.Synonym: graft or grafting. TEMPs may be applied to arecipient by implantation or grafting. F22103.4.10 recipient, nthe individual or organism into whommaterials are grafted or implanted. F22103.4.11 split thickness skin autograft, na skin autograftconsisting of the epidermis and a porti
46、on of dermis. F23123.4.12 transplantation, nfor therapeutic purposes, the pro-cess of implanting in one part, cells, tissue(s), or organ(s) takenfrom another part or from another individual. Some (but notall) forms of transplantation are regulated by the U.S. Food andDrug Administration (FDA) under
47、21 CFR Parts 16 and 1270(1) and 21 CFR Parts 207, 807, and 1271 (2). F22103.4.13 xenocultured cell, na cell that is a xenotransplan-tation product.3.4.13.1 DiscussionXenografts and xenotransplantationproducts comprise overlapping but not congruent groups ofskin substitutes. Autograft, allograft, and
48、 xenograft are tradi-tional terms to describe tissue used in surgical procedures.Because autograft involves the harvesting of the patients owntissue, care is taken to preserve its viability. However, allograftand xenograft are not necessarily alive and may have beenfrozen for storage. Skin substitut
49、es may combine attributes ofautograft, allograft, xenograft, and xenotransplantationproduct, depending on the origin of cells or tissues used in theirmanufacture, and whether these components are alive or not.For example, a skin substitute consisting of viable autologousepidermal cells grown on a feeder layer of metabolicallyactive, non-replicating murine cells may be both autologousand a xenotransplantation product.3.4.14 xenograft, na graft of tissue transplanted betweenanimals of diff
