Sheet-like composition
View Patent ↗A sheet-shaped composition is provided which has an improved preservability and handling readiness, as well as a high flexibility in use. Amnion with trehalose added thereto is utilized. Addition of trehalose improves the flexibility of the amnion, and prevents basal membrane and stratum compactum from being damaged during lyophilization process.
1. A sheet-shaped composition comprising an amnion having its epithelial cell layer removed, said composition lyophilized and trehalose-treated, wherein said composition has an enhanced tensile strength compared to raw amnion.
2. The sheet-shaped composition according to claim 1 in a frozen or desiccated state.
3. The sheet-shaped composition according to claim 1 wherein said composition has an increased clarity compared to a sheet-like composition comprising amnion with epithelium removed, lyophilized, which has not been trehalose-treated, and wherein said increased clarity is capable of being evaluated by measuring turbidity, calculated according to the equation: Haze=Diffuse Transmission Factor (DF)/Total Light Transmittance.
4. The sheet-shaped composition according to claim 1 , wherein said amnion has basal membrane components Collagen IV, Collagen VII, and Laminin 5 that are detected at an equivalent intensity to that in untreated amnion.
5. The sheet-shaped composition according to claim 1 , wherein said amnion is a human amnion.
6. The sheet-shaped composition according to claim 1 , wherein a cell layer consisting of tissue-derived cells is formed on said amnion.
7. The sheet-shaped composition according to claim 6 , wherein said tissue-derived cells are layered in the cell layer.
8. The sheet-shaped composition according to claim 6 , wherein said tissue-derived cells are derived from corneal epithelium, conjunctival epithelium, skin epidermis, follicular epithelium, oral mucosa epithelium, pigment epithelium iris, pigment epithelium retina, airway mucosa epithelium, or intestinal mucosa.
9. The sheet-shaped composition according to claim 6 , wherein said cell layer is composed of about 5-7 layered cells, and has properties similar to those of corneal epithelium.
10. The sheet-shaped composition according to claim 1 , for use as antiadhesive materials or reconstruction materials for surface of tissues damaged during surgical invasion.
11. The sheet-shaped composition according to claim 1 , wherein said amnion has an adhesive component attached on its chorion side surface.
12. The sheet-shaped composition according to claim 11 , wherein said adhesive component comprises fibrinogen and thrombin.
13. The sheet-shaped composition according to claim 11 , wherein said adhesive component comprises fibrinogen, thrombin and aprotinin.
14. The sheet-shaped composition according to claim 1 , wherein the chorion side surface of the amnion is covered with bioabsorbable material.
15. A Transplant method using the sheet-shaped composition according to claim 1 as implant material.
16. A method for producing a sheet-shaped composition, comprising the steps of:
(a) preparing an amnion having its epithelial cell layer removed; and
(b) adding trehalose to said amnion;
(c) freezing or desiccating said amnion.
17. The method according to claim 16 , further comprising the step of: (d) sterilizing said amnion after step (c).
18. The method according to claim 16 , wherein step (a) comprises the following steps of:
(i) separating an amnion from an organism,
(ii) freeze-thawing said amnion,
(iii) subjecting said amnion after freeze-thawing to tryptic treatment,
(iv) washing said amnion after tryptic treatment.
19. The method according to claim 18 , wherein the freezing temperature during said freeze-thawing process is from about −20° C. to about −80° C., and the thawing temperature is from about 4° C. to about 50° C.
20. The method according to claim 18 , characterized by repetition of said freeze-thawing process twice or more times.
21. The method according to claim 18 , characterized by the tryptic treatment being performed using a tryptic solution having a tryptic concentration of from about 0.01% (w/v) to about 0.05% (w/v).
22. The method according to claim 21 , characterized by the tryptic solution comprising from about 0.1 mM to about 0.6 mM of a chelator selected from the group consisting of EDTA, NTA, DTPA, HEDTA, GLDA, and any combination thereof.
23. The method according to claim 18 , characterized by the tryptic treatment being performed under the condition such that the tryptic solution is contacted with only the epithelium side of said amnion.
24. The method according to claim 16 , wherein the following step of forming a cell layer consisting of tissue-derived cells on said amnion is performed after step (b).