Placental tissue grafts

• US 9,272,003 B2
• Filed: 04/25/2014
• Issued: 03/01/2016
• Est. Priority Date: 09/07/2007
• Status: Active Grant

• Current Assignee: Mimedx Group Incorporated
• Original Assignee: Mimedx Group Incorporated
• Inventors: Daniel, John, Spencer, Randall, Russo, John, Tofe, Robert
• Primary Examiner(s): FOX, ALLISON M
• Application Number:
  US14/262,590
• Publication Number:
  US 20140234387A1
• Time in Patent Office: 676 Days
• Field of Search: 424/583
• US Class Current: 1/1
• CPC Class Codes: A61F 2210/00 Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
• CPC Class Codes: A61F 2230/00 Geometry of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
• CPC Class Codes: A61K 35/19 Platelets; Megacaryocytes
• CPC Class Codes: A61K 35/28 Bone marrow; Haematopoietic stem cells; Mesenchymal stem cells of any origin, e.g. adipose-derived stem cells
• CPC Class Codes: A61K 35/33 Fibroblasts
• CPC Class Codes: A61K 35/50 Placenta; Placental stem cells; Amniotic fluid; Amnion; Amniotic stem cells
• CPC Class Codes: A61L 2430/34 for soft tissue reconstruction
• CPC Class Codes: A61L 2430/40 Preparation and treatment of biological tissue for implantation, e.g. decellularisation, cross-linking
• CPC Class Codes: 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
• CPC Class Codes: 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
• CPC Class Codes: A61L 27/3834 Cells able to produce different cell types, e.g. hematopoietic stem cells, mesenchymal stem cells, marrow stromal cells, embryonic stem cells
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61P 41/00 Drugs used in surgical methods, e.g. surgery adjuvants for preventing adhesion or for vitreum substitution
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 156/1039 Surface deformation only of sandwich or lamina [e.g., embossed panels]

Abstract

Described herein are tissue grafts derived from the placenta. The grafts are composed of at least one layer of amnion tissue where the epithelium layer has been substantially removed in order to expose the basement layer to host cells. By removing the epithelium layer, cells from the host can more readily interact with the cell-adhesion bio-active factors located onto top and within of the basement membrane. Also described herein are methods for making and using the tissue grafts. The laminin structure of amnion tissue is nearly identical to that of native human tissue such as, for example, oral mucosa tissue. This includes high level of laminin-5, a cell adhesion bio-active factor show to bind gingival epithelia-cells, found throughout upper portions of the basement membrane.

Claims

1. A method for preparing a dehydrated tissue graft, comprising the steps:

a) obtaining a placenta comprising an amnion and a chorion;

b) separating the amnion from the chorion;

c) washing and cleaning the amnion and optionally the chorion, wherein the amnion comprises an epithelial cellular side and a fibroblast cellular side;

d) substantially removing all of the epithelial cells from the epithelial cellular side of the amnion while retaining fibroblast cells in the fibroblast cellular side;

e) forming a multilayered graft by placing the amnion or the chorion on a surface to form a first layer and then placing one or more additional layers over the first layer to produce a multilayered tissue graft, wherein at least one layer comprises the amnion with the epithelial cells substantially removed while retaining fibroblast cells, and wherein the one or more additional layers is not Wharton'"'"'s jelly; and

f) dehydrating the multilayered tissue graft.

2. The method of claim 1, wherein after step (b) but prior to step (c), the method further comprises the steps of soaking the amnion in an antibiotic solution and then removing the antibiotic solution.

3. The method of claim 1, wherein the one or more additional layers comprises amnion, chorion, allograft pericardium, allograft acelluar dermis, amniotic membrane, purified xenograft Type-1 collagen, biocellulose polymers or copolymers, biocompatible synthetic polymer or copolymer films, purified small intestinal submucosa, bladder acellular matrix, cadaveric fascia, or any combination thereof.

4. The method of claim 1, wherein the one or more additional layers comprise chorion, amnion, or a combination thereof.