Placental tissue grafts

• US 9,415,074 B2
• Filed: 10/21/2015
• Issued: 08/16/2016
• 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:
  US14/919,692
• Publication Number:
  US 20160038638A1
• Time in Patent Office: 300 Days
• Field of Search: None
• 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 dehydrated, laminated bilayer tissue graft consisting essentially of

a) a washed, cleaned and dehydrated amnion layer isolated from a placenta;

b) a washed, cleaned and dehydrated chorion layer isolated from a placenta;

wherein the amnion layer has a first side which is an exposed basement membrane and a second side which is a fibroblast layer, and further wherein the chorion is in direct contact with the amnion and the two layers are laminated together.

2. The dehydrated, laminated tissue graft of claim 1, wherein the amnion layer and the chorion layer are isolated from the same placenta.

3. The dehydrated, laminated tissue graft of claim 1, wherein one or both of the amnion layer and the chorion layer are treated with an antibiotic prior to lamination.

4. The dehydrated, laminated tissue graft of claim 1, wherein the tissue graft has been exposed to sterilizing conditions.

5. A dehydrated, laminated bilayer tissue graft, wherein the tissue graft consists essentially of an amnion layer and a chorion layer, wherein each of the amnion and chorion layers:

a) is separated from a placenta to provide separated layers of amnion and chorion;

b) is washed and substantially cleaned; and

c) is layered directly over the other and heat dehydrated and laminated to provide the dehydrated, laminated bilayer tissue graft;

wherein the amnion has a first side which is an exposed basement membrane and a second side which is a fibroblast layer.

6. The dehydrated, laminated tissue graft of claim 5, wherein at least one of the amnion layer or chorion layer has been chemically decontaminated.