Crosslinked human or animal tissue products and their methods of manufacture and use
Degradable bioprostheses made of collagen-based material having amine-based and ester-based crosslinks are provided, as are methods for their formation and use. Some embodiments of the present invention are directed towards a method of controlling the ratio of amine-based crosslinks to ester-based crosslinks within a collagen-based material to provide a tailorably crosslinked collagen-based material. Some embodiments provide a method of making a degradable bioprosthesis involving controlling crosslinking to afford a degradable bioprosthesis that is partially crosslinked. By controlling the ratio of amine-based to ester-based crosslinks, by controlling the level of crosslinking, or by controlling both of these features, degradable bioprostheses with tailored degradation rates can be synthesized. Some embodiments of degradable bioprostheses have degradation rates that are tailored to allow their use in particular medical applications. Some embodiments are directed towards methods of use degradable bioprostheses in wound healing, tissue repair, and tissue supplementation.
1. A cross-linked collagen-based material comprising Crosslink A, Crosslink B, and free amines (—NH 2 ):
wherein:
indicates collagen strands;
R 1 is
R 2 is
R 3 and R 4 are independently selected from the group consisting of —CH 2 —O—(CH 2 ) n —O—CH 2 — and —CH 2 —(O(CH 2 ) n ) m —O—CH 2 —,
n and m are independently an integer from 1-6, and
the amount of free amines (—NH 2 ) on the collagen strands is between 50% and 85% relative to the total amount of free amines (—NH 2 ) prior to crosslinking, and the ratio of Crosslink A and Crosslink B is from about 80:20 to about 20:80.
2. The crosslinked collagen-derived material of claim 1 , wherein R 3 and R 4 are the same.
3. The crosslinked collagen-based material of claim 1 , wherein the ratio of Crosslink A and Crosslink B is from about 170:30 to about 30:70.
4. The crosslinked collagen-derived material of claim 1 , wherein the crosslinked collagen-derived material has a degradation rate between about 0.2% to about 1.1% per hour when subjected to a pronase digestion assay.
5. A degradable bioprosthesis, comprising:
a cross-linked collagen-based material comprising Crosslink A, Crosslink B, and free amines (—NH 2 ):
wherein:
indicates collagen strands;
R 1 is
R 2 is
R 3 and R 4 are independently selected from the group consisting of —CH 2 —O—(CH 2 ) n —O—CH 2 — and —CH 2 —(O(CH 2 ) n ) m —O—CH 2 —,
n and m are independently an integer from 1-6, and
the amount of free amines (—NH 2 ) on the collagen strands is between 50% and 85% relative to the total amount of free amines (—NH 2 ) prior to crosslinking, and the ratio of Crosslink A and Crosslink B is from about 80:20 to about 20:80.
6. The crosslinked collagen-derived material of claim 5 , wherein R 3 and R 4 are the same.
7. The crosslinked collagen-based material of claim 5 , wherein the ratio of Crosslink A and Crosslink B is from about 70:30 to about 30:70.
8. The crosslinked collagen-derived material of claim 5 , wherein the crosslinked collagen-derived material has a degradation rate between about 0.2% to about 1.1% per hour when subjected to a pronase digestion assay.
9. A degradable bioprosthesis comprising:
a tailorable cross-linked collagen-based material comprising Crosslink A, Crosslink B, and free amines (—NH 2 ):
wherein:
indicates collagen strands;
R 1 is
R 2 is
R 3 and R 4 are independently selected from the group consisting of —CH 2 —O—(CH 2 ) n —O—CH 2 — and —CH 2 —(O(CH 2 ) n ) m —O—CH 2 —,
n and m are independently an integer from 1-6; and
the tailorable cross-linked collagen-based material has a degradation rate between 0.27% to 0.88% per hour when subjected to a pronase digestion assay.
10. The degradable bioprosthesis of claim 9 , wherein the collagen strands are derived from animal pericardium.
11. The degradable bioprosthesis of claim 9 , having a shrinkage temperature (Ts) above about 70° C.
12. The degradable bioprosthesis of claim 9 , wherein the shrinkage temperature is inversely proportional to the amount of free amines on the collagen strands.
13. The degradable bioprosthesis of claim 9 , wherein the amount of free amines on the collagen strands is between about 50% and about 85% relative to the total amount of free amines (—NH 2 ) prior to crosslinking.
14. The degradable bioprosthesis of claim 9 , wherein the degradation rate is directly proportional to the amount of free amines on the collagen strands.
15. The degradable bioprosthesis of claim 9 , wherein the ratio of amine-based crosslinks to ester-based crosslinks is about 100:1 to about 1:100.
16. The degradable bioprosthesis of claim 9 , wherein the degradable bioprosthesis comprises a flexible sheet.
17. The degradable bioprosthesis of claim 16 , wherein the flexible sheet is between about 1 cm 2 and about 500 cm 2 .
18. The degradable bioprosthesis of claim 16 , wherein the flexible sheet is treated with antimicrobial agent.