PLACENTAL TISSUE GRAFTS

• US 20130337035A1
• Filed: 07/30/2013
• Published: 12/19/2013
• Est. Priority Date: 08/17/2006
• Status: Active Grant

• Current Assignee: Mimedx Group Incorporated
• Original Assignee: Mimedx Group Incorporated
• Inventors: Daniel, John
• Granted Patent: US 8,709,494 B2
• Time in Patent Office: Days
• US Class Current: 424/443
• CPC Class Codes: A61K 35/50 Placenta; Placental stem cells; Amniotic fluid; Amnion; Amniotic stem cells
• CPC Class Codes: A61L 2300/412 Tissue-regenerating or healing or proliferative agents
• CPC Class Codes: A61L 2300/60 characterised by a special physical form
• 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 27/3691 characterised by physical conditions of the treatment, e.g. applying a compressive force to the composition, pressure cycles, ultrasonic/sonication or microwave treatment, lyophilisation
• CPC Class Codes: A61L 27/50 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: A61L 27/58 Materials at least partially resorbable by the body

Abstract

A method for preparing placenta membrane tissue grafts for medical use, includes obtaining a placenta from a subject, cleaning the placenta, separating the chorion tissue from the amniotic membrane, mounting a selected layer of either the chorion tissue or the amniotic membrane onto a drying fixture, dehydrating the selected layer on the drying fixture, and cutting the selected layer into a plurality of tissue grafts. Preferably, the drying fixture includes grooves or raised edges that define the outer contours of each desired tissue graft, after they are cut, and further includes raised or indented logos that emboss the middle area of the tissue grafts during dehydration and that enables an end user to distinguish the top from the bottom side of the graft. The grafts are comprised of single layers of amnion or chorion, multiple layers of amnion or chorion, or multiple layers of a combination of amnion and chorion.

Claims

1-20. -20. (canceled)

21. A dehydrated, laminated tissue graft consisting essentially of one or more washed and/or substantially cleaned amnion layers and one or more washed and/or substantially cleaned chorion layers that are directly assembled, laminated and dehydrated together.

22. The tissue graft of claim 21, wherein said assembled and laminated layers are dehydrated together in a drying fixture.

23. The dehydrated, laminated tissue graft of claim 21, wherein one or both of the one or more amnion layers and the one or more chorion layers is treated with an antibiotic prior to lamination.

24. The tissue graft of claim 21, wherein the tissue graft has been exposed to sterilizing conditions.

25. The tissue graft of claim 21, consisting essentially of one amnion layer and one chorion layer.

26. The tissue graft of claim 21, consisting essentially of multiple amnion layers.

27. The tissue graft of claim 21, consisting essentially of multiple chorion layers.

28. A dehydrated, laminated tissue graft, wherein the tissue graft consists essentially of one or more amnion layers and one or more chorion layers wherein each of the amnion and chorion layers:

are separated from a placenta to provide separate layers of amnion and chorion,

washed and substantially cleaned, and

are layered directly over each other and are laminated and dehydrated together to provide the dehydrated, laminated tissue graft.

29. The tissue graft of claim 28, consisting essentially of one amnion layer and one chorion layer.

30. The tissue graft of claim 28, consisting essentially of multiple amnion layers.

31. The tissue graft of claim 28, consisting essentially of multiple chorion layers.

32. The tissue graft of claim 28, wherein at least one of the amnion or chorion layers has been chemically decontaminated.

44. A scaled package comprising one or more of the following within a sealed package:

a tissue graft of claim 28;

a dehydrated, laminated tissue graft consisting essentially of one or more washed and/or substantially cleaned amnion layers and one or more washed and/or substantially cleaned chorion layers that are directly assembled, laminated and dehydrated together;

a dehydrated, laminated tissue graft, wherein the tissue graft comprises at least one amnion layer separated from its placental chorion layer, wherein at least one amnion layer is washed and substantially cleaned, the graft further comprising one or more additional chorion layers; and

further wherein said at least one amnion layer and said one more chorion layers are assembled, laminated and dehydrated together; and

a laminated tissue graft, wherein the tissue graft consists essentially of one or more intact amnion layers and one or more chorion layers;

wherein said amnion and chorion layers have been washed and/or substantially cleaned; and

further wherein said amnion and chorion layers are laminated together and dehydrated in a drying fixture.

45. The sealed package of claim 44, wherein the tissue graft within the sealed package has been exposed to sterilizing conditions.

46. The sealed package of claim 44, wherein the sealed package is further contained within a second outer package.

47. A method for treating a subject with the tissue graft comprising extracting the tissue graft. from a package and contacting the subject with said tissue graft, wherein the tissue graft is selected from one or more of the following:

a tissue graft of claim 28;

a dehydrated, laminated tissue graft consisting essentially of one or more washed and/or substantially cleaned amnion layers and one or more washed and/or substantially cleaned chorion layers that are directly assembled, laminated and dehydrated together;

a dehydrated, laminated tissue graft, wherein the tissue graft comprises at least one amnion layer separated from its placental chorion layer, wherein at least one amnion layer is washed and substantially cleaned, the graft further comprising one or more additional chorion layers; and

further wherein said at least one amnion layer and said one more chorion layers are assembled, laminated and dehydrated together; and

a laminated tissue graft, wherein the tissue graft consists essentially of one or more intact amnion layers and one or more chorion layers;

wherein said amnion and chorion layers have been washed and/or substantially cleaned; and

further wherein said amnion and chorion layers are laminated together and dehydrated in a drying fixture.

48. An apparatus comprising a drying fixture and one or more of the following:

a tissue graft of claim 28;

a dehydrated, laminated tissue graft consisting essentially of one or more washed and/or substantially cleaned amnion layers and one or more washed and/or substantially cleaned chorion layers that are directly assembled, laminated and dehydrated together;

a dehydrated, laminated tissue graft, wherein the tissue graft comprises at least one amnion layer separated from its placental chorion layer, wherein at least one amnion layer is washed and substantially cleaned, the graft further comprising one or more additional chorion layers; and

further wherein said at least one amnion layer and said one more chorion layers are assembled, laminated and dehydrated together; and

a laminated tissue graft, wherein the tissue graft consists essentially of one or more intact amnion layers and one or more chorion layers;

wherein said amnion and chorion layers have been washed and/or substantially cleaned; and

further wherein said amnion and chorion layers are laminated together and dehydrated in a drying fixture.

33. A dehydrated, laminated tissue graft, wherein the tissue graft comprises at least one amnion layer separated from its placental chorion layer, wherein at least one amnion layer is washed and substantially cleaned, the graft further comprising one or more additional chorion layers;

and further wherein said at least one amnion layer and said one more chorion layers are assembled, laminated and dehydrated together.

34. The dehydrated, laminated tissue graft of claim 33, wherein one or both of the at least one amnion layers and the one or more chorion layers has been treated with an antibiotic.

35. The tissue graft of claim 33, wherein the tissue graft has been exposed to sterilizing conditions.

36. The tissue graft of claim 33, consisting essentially of one amnion layer and one chorion layer.

37. The tissue graft of claim 33, consisting essentially of multiple amnion layers.

38. The tissue graft of claim 33, consisting essentially of multiple chorion layers.

39. A laminated tissue graft, wherein the tissue graft consists essentially of one or more intact amnion layers and one or more chorion layers;

wherein said amnion and chorion layers have been washed and/or substantially cleaned; and

further wherein said amnion and chorion layers are laminated together and dehydrated in a drying fixture.

40. The tissue graft of claim 39, wherein at least one of the amnion or chorion layers has been chemically decontaminated.

41. The tissue graft of claim 39, consisting essentially of one amnion layer and one chorion layer.

42. The tissue graft of claim 39, consisting essentially of multiple chorion layers.

43. The tissue graft of claim 39, consisting essentially of more than one amnion layer.