Flat self-curling permeable sheet membrane
View Patent ↗A flat self-curling permeable sheet membrane containing a matrix formed of crosslinked biopolymeric fibers. The matrix self-curls into a predetermined shape upon absorption of an aqueous fluid and is permeable to molecules having molecular weights not greater than 1×10 6 daltons. Also disclosed is a method of preparing such a flat self-curling permeable membrane.
1. A dry flat self-curling permeable sheet membrane comprising a flat layer of crosslinked collagen fibers, wherein the sheet membrane is free of chitosan and glycosaminoglycan, and the flat layer self-curls into a predetermined shape upon absorption of an aqueous fluid, the predetermined shape being a v, a tube, an arch, or a channel, and is permeable to molecules having molecular weights not greater than 1×10 6 daltons.
2. The membrane of claim 1 , wherein the flat layer has a thickness of 0.2-1.2 mm, a density of 0.1-0.8 g/cm 3 , a hydrothermal shrinkage temperature of 50-85° C., a suture pullout strength of 0.1-3.0 kg, an in vivo resorption time of 2-18 months, a self-curling time of 10-80 seconds, a tensile strength of 50-300 kg/cm 2 , and a compression resistance of 0.1-10 N.
3. The membrane of claim 2 , wherein the collagen fibers are oriented.
4. The membrane of claim 2 , wherein the collagen fibers are type I collagen fibers.
5. The membrane of claim 4 , wherein the collagen fibers are oriented.
6. The membrane of claim 3 , further comprising a bioactive agent.
7. The membrane of claim 2 , wherein the flat layer is permeable to molecules having molecular weights not greater than 5.0×10 5 daltons, and has a thickness of 0.4-0.8 mm, a density of 0.4-0.7 g/cm 3 , a hydrothermal shrinkage temperature of 52-80° C., a suture pullout strength of 0.2-1.5 kg, an in vivo resorption time of 3-12 months, a self-curling time of 20-65 seconds, a tensile strength of 65-200 kg/cm 2 , and a compression resistance of 0.5-9 N.
8. The membrane of claim 7 , wherein the collagen fibers are oriented.
9. The membrane of claim 7 , wherein the collagen fibers are type I collagen fibers.
10. The membrane of claim 9 , wherein the collagen fibers are oriented.
11. The membrane of claim 8 , further comprising a bioactive agent.
12. A method for preparing a dry flat self-curling permeable sheet membrane, the method comprising:
reconstituting biopolymeric fibers dispersed in a solution;
forming a permeable sheet membrane containing a layer of the reconstituted biopolymeric fibers;
folding the sheet membrane in a hydrated state into a predetermined shape;
crosslinking the biopolymeric fibers while the folded sheet membrane is kept in the predetermined shape; and
flattening the folded sheet membrane in a hydrated state followed by drying, thereby forming a flat membrane that self-curls into the predetermined shape upon absorption of an aqueous fluid,
wherein the predetermined shape is a v, a tube, an arch, or a channel, the sheet membrane is free of chitosan and glycosaminoglycan, and the biopolymeric fibers are collagen fibers.
13. The method of claim 12 , wherein the biopolymeric fibers are type I collagen fibers.
14. The method of claim 12 , wherein the forming step includes:
placing the reconstituted biopolymeric fibers around a mandrel;
rotating the mandrel to form a tubular layer of oriented biopolymeric fibers; and
cutting the tubular layer to form a sheet membrane.
15. The method of claim 14 , wherein the biopolymeric fibers are type I collagen fibers.
16. A dry flat self-curling permeable sheet membrane prepared by the steps of:
reconstituting biopolymeric fibers dispersed in a solution;
forming a permeable sheet membrane containing a layer of the reconstituted biopolymeric fibers;
folding the sheet membrane in a hydrated state into a predetermined shape;
crosslinking the biopolymeric fibers while the folded sheet membrane is kept in the predetermined shape; and
flattening the folded sheet membrane in a hydrated state followed by drying, thereby forming a flat membrane that self-curls into the predetermined shape upon absorption of an aqueous fluid,
wherein the predetermined shape is a v, a tube, an arch, or a channel, the sheet membrane is free of chitosan and glycosaminoglycan, and the biopolymeric fibers are collagen fibers.
17. The dry flat self-curling permeable sheet membrane of claim 16 , wherein the biopolymeric fibers are type I collagen fibers.
18. The dry flat self-curling permeable sheet membrane of claim 16 , wherein the forming step includes:
placing the reconstituted biopolymeric fibers around a mandrel;
rotating the mandrel to form a tubular layer of oriented biopolymeric fibers; and
cutting the tubular layer to form a sheet membrane.
19. The dry flat self-curling permeable sheet membrane of claim 18 , wherein the biopolymeric fibers are type I collagen fibers.
20. A dry flat self-curling permeable sheet membrane consisting of a flat layer of crosslinked collagen fibers, wherein the flat layer self-curls into a predetermined shape upon absorption of an aqueous fluid, the predetermined shape being a v, a tube, an arch, or a channel, and is permeable to molecules having molecular weights not greater than 1×10 6 daltons.