Placental tissue grafts and methods of preparing and using the same

• US 9,533,011 B2
• Filed: 02/03/2014
• Issued: 01/03/2017
• 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:
  US14/171,511
• Publication Number:
  US 20140290837A1
• Time in Patent Office: 1,065 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 method for preparing a de-epithelialized multilayer laminate comprising at least one amnion layer which method comprises:

placing at least one modified amnion layer comprising a first side which is an exposed basement membrane and a second side which retains a fibroblast cellular layer in contact with a second layer such that the amnion layer is positioned to contact its fibroblast cellular layer with the second layer;

optionally adding one or more additional layers to said amnion or to said second layer; and

dehydrating and laminating the layers under heated conditions;

wherein the second layer is selected from the group consisting of amnion, chorion, allograft pericardium, allograft acellular dermis, amniotic membrane, Wharton'"'"'s jelly, a biocellulose polymer or copolymers, purified small intestinal submucosa, bladder acellular matrix, cadaveric fascia, and a combination thereof.

2. The method of claim 1, wherein the second layer is amnion or chorion.

3. The method of claim 1, wherein the dehydrating and laminating are conducted in a drying fixture.

4. The method of claim 3, wherein the surface of the drying fixture has a plurality of grooves that defines the outer contours of each of the plurality of placenta.

5. The method of claim 3, wherein the drying fixture includes a texture or design adapted to emboss such texture or design into the basement membrane during dehydration.

6. The method of claim 1, wherein the heated conditions comprise a temperature of between 35°

C. and 50°

C. and a period of between 30 and 120 minutes.

7. The method of claim 1, wherein the one or more additional layers comprises amnion, chorion, allograft pericardium, allograft acellular dermis, amniotic membrane, Wharton'"'"'s jelly, 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.

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