Placental tissue grafts

Patent metadata

Field	Value
Publication number	US-9272003-B2
Application number	US-201414262590-A
Country	US
Kind code	B2
Filing date	Apr 25, 2014
Priority date	Sep 7, 2007
Publication date	Mar 1, 2016
Grant date	Mar 1, 2016

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.

First claim

What is claimed is:

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.

Assignees

• Mimedx Group Inc

Inventors

• Daniel John
• Spencer Randall
• Russo John
• Tofe Robert

Classifications

• A61P41/00

  Drugs used in surgical methods, e.g. surgery adjuvants for preventing adhesion or for vitreum substitution · CPC title

• A61L27/3834

  Cells able to produce different cell types, e.g. hematopoietic stem cells, mesenchymal stem cells, marrow stromal cells, embryonic stem cells · CPC title

• A61K35/33

  Fibroblasts · CPC title

• A61K35/19

  Platelets; Megacaryocytes · CPC title

• A61L27/3683 Primary

  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 title