# US 9,433,647 B2 · Placental tissue grafts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,433,647 B2 - Document ID: US9433647B2 - Status: Granted - Kind: B2 - Application number: 14/222,510 - Filed: 2014-03-21 - Published: 2014-09-25 - Granted: 2016-09-06 - Earliest claimed: 2006-08-17 - Assignees: MiMedx Group, Inc. - Applicants: MiMedx Group, Inc. - Inventors: John Daniel - Web page: https://patentgrep.com/patent/US9433647B2 ## CPC - A61L 27/3604: {characterised by the human or animal origin of the biological material, e.g. hair, fascia, fish scales, silk, shellac, pericardium, pleura, renal tissue, amniotic membrane, parenchymal tissue, fetal tissue, muscle tissue, fat tissue, enamel} - A61K 35/50: Placenta; Placental stem cells; Amniotic fluid; Amnion; Amniotic stem cells - A61L 27/3683: {subjected to a specific treatment prior to implantation, e.g. decellularising, demineralising, grinding, cellular disruption/non-collagenous protein removal, anti-calcification, crosslinking, supercritical fluid extraction, enzyme treatment} - A61L 27/3691: {characterised by physical conditions of the treatment, e.g. applying a compressive force to the composition, pressure cycles, ultrasonic/sonication or microwave treatment, lyophilisation} - A61L 27/50: Materials characterised by their function or physical properties {, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials} - A61L 27/54: Biologically active materials, e.g. therapeutic substances {(A61L27/227 takes precedence)} - A61L 27/58: Materials at least partially resorbable by the body - A61L 2300/412: Tissue-regenerating or healing or proliferative agents - A61L 2300/60: characterised by a special physical form - A61L 2430/40: Preparation and treatment of biological tissue for implantation, e.g. decellularisation, cross-linking - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) ## Abstract A method for preparing placenta membrane tissue grafts for medical use, includes obtaining a placenta from a subject, cleaning the placenta, separating the chorion tissue from the amniotic membrane, mounting a selected layer of either the chorion tissue or the amniotic membrane onto a drying fixture, dehydrating the selected layer on the drying fixture, and cutting the selected layer into a plurality of tissue grafts. Preferably, the drying fixture includes grooves or raised edges that define the outer contours of each desired tissue graft, after they are cut, and further includes raised or indented logos that emboss the middle area of the tissue grafts during dehydration and that enables an end user to distinguish the top from the bottom side of the graft. The grafts are comprised of single layers of amnion or chorion, multiple layers of amnion or chorion, or multiple layers of a combination of amnion and chorion. ## Claims ### Claim 1 A method for forming a dehydrated, laminated tissue graft, comprising the steps of: a) placing a first wet placental tissue onto a receiving surface of a drying fixture, wherein the receiving surface includes a slightly raised or indented texture or design adapted to provide a label into the placental tissue b) placing at least one additional wet placental tissue adjacent to the first wet placental tissue; c) drying the placental tissues under conditions using heat, such that a dehydrated, laminated tissue graft having a label is formed; and d) removing the tissue graft from the drying fixture, wherein the receiving surface allows the tissue graft to be removed while maintaining the label; wherein when at least one placental tissue is an amnion, said method does not substantially remove all of the epithelial cells on at least one amnion. ### Claim 2 (depends on 1) The method of claim 1, wherein the receiving surface comprises polytetrafluoroethylene. ### Claim 3 (depends on 1) The method of claim 1, wherein the receiving surface comprises polyoxymethylene. ### Claim 4 (depends on 1) The method of claim 1, wherein the first wet placental tissue and/or at least one additional wet placental tissue is amnion. ### Claim 5 (depends on 1) The method of claim 1, wherein the first wet placental tissue and/or at least one additional wet placental tissue is chorion. ### Claim 6 (depends on 1) The method of claim 1 wherein the first wet placental tissue and/or at least one additional wet placental tissue comprises at least one cellular layer. ### Claim 7 (depends on 6) The method of claim 6, wherein the at least one cellular layer is a fibroblast cellular layer. ### Claim 8 (depends on 7) The method of claim 7, wherein the fibroblast cellular layer is adjacent to the next placental tissue. ### Claim 9 (depends on 1) The method of claim 1 wherein the slightly indented texture or design comprises a plurality of grooves. ### Claim 10 (depends on 1) The method of claim 1 wherein the slightly raised texture or design comprises a plurality of raised edges or blades. ### Claim 11 (depends on 9) The method of claim 9, wherein the plurality of grooves defines a product space, wherein the texture or design is an indented asymmetric texture within the product space which has an otherwise smooth surface, such that a portion of the placental tissue placed within the product space molds around the texture thereby creating an asymmetric label on the placental tissue grafts. ### Claim 12 (depends on 10) The method of claim 10, wherein the plurality of raised edges or blades defines a product space, wherein the texture or design is a raised asymmetric texture within the product space which has an otherwise smooth surface, such that a portion of the placental tissue placed within the product space molds around the texture thereby creating an asymmetric label on the placental tissue grafts.