Human placental tissue graft products, methods, and apparatuses
Provided herein are tissue grafts, and in particular human placenta-derived tissue grafts and methods and articles for the manufacture and use thereof.
1. A method of producing a tissue graft, the method comprising:
removing decidua cells and trophoblast cells from a fetal support tissue membrane;
compressing the membrane;
dehydrating the membrane;
decontaminating the membrane; and
mounting the membrane to a: flexible backing material to produce a formed tissue graft;
wherein the native connective architecture between an amnion layer and a chorion layer of the membrane is maintained intact throughout the method,
wherein the amnion layer is not decellularized,
wherein the steps of compressing the membrane and dehydrating the membrane are performed simultaneously, and wherein the steps of compressing the membrane and dehydrating the membrane comprise positioning the membrane between a moisture-permeable support platform and a gas-impermeable sealing sheet, then depressurizing a chamber below the moisture-permeable support platform to pull a vacuum across the platform using a vacuum source,
wherein the chamber, being below the moisture-permeable support platform, defines an opening at one end, the chamber being in fluid connection with the vacuum source, and
wherein the moisture-permeable support platform covers the opening of the chamber and comprises a perforated rigid support layer and a moisture, liquid, and vapor permeable material layer, wherein the moisture, liquid, and vapor permeable material layer is positioned between the perforated rigid support layer and the membrane, and wherein the membrane is positioned between the gas-impermeable sealing sheet and the moisture, liquid, and vapor permeable material layer.
2. The method of claim 1 , further comprising retaining at least 10,000 pg/mg of native basic fibroblast growth factor (bFGF) from the membrane in the formed tissue graft.
3. The method of claim 1 , further comprising swelling the decidua cells and the trophoblast cells prior to removing the decidua cells and the trophoblast cells.
4. The method of claim 3 , wherein swelling the decidua cells and the trophoblast cells further comprises contacting a maternal side of the membrane with a hypotonic solution.
5. The method of claim 4 , wherein the decidua cells and the trophoblast cells are mechanically removed after swelling.
6. The method of claim 3 , wherein removing the decidua cells and the trophoblast cells from the membrane reduces the alloantigenicity to a Stimulation Index of less than 1 when measured by a peripheral blood mononuclear cell BrdU proliferation assay.
7. The method of claim 1 , wherein decontaminating the membrane comprises treating the membrane with buffered peracetic acid.
8. The method of claim 7 , wherein the concentration of buffered peracetic acid is from about 0.01% to about 1% v/v.
9. The method of claim 1 , wherein compressing the membrane further comprises applying a load to a surface of the membrane opposite the platform.
10. The method of claim 1 , wherein dehydrating the membrane further comprises flowing air through the chamber while the chamber is in a sealed state.
11. The method of claim 1 , wherein the moisture, liquid, and vapor permeable layer is a nonwoven or flashspun material.
12. The method of claim 1 , wherein the gas-impermeable sealing sheet comprises silicone.
13. The method of claim 1 , further comprising forming on the membrane a first, shiny surface adjacent to the gas-impermeable sealing sheet and a second, less shiny surface adjacent to the moisture, liquid, and vapor permeable layer.
14. The method of claim 1 , wherein dehydrating the membrane comprises sinking moisture from the membrane using a desiccant material.
15. The method of claim 1 , wherein mounting the membrane to a flexible backing material comprises releasably securing opposed ends of the membrane between two opposed tabs.
16. The method of claim 15 , wherein the flexible backing material is larger than the membrane.
17. A method of using the tissue graft of claim 1 , the method comprising storing the formed tissue graft at room temperature for at least six months and applying the formed tissue graft to a patient.