Placental tissue grafts and methods of preparing and using the same
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.
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.