Multi-step connective tissue stabilization method and stabilized tissue formed thereby

• US 9,795,573 B2
• Filed: 09/24/2014
• Issued: 10/24/2017
• Est. Priority Date: 09/24/2013
• Status: Active Grant

• Current Assignee: Clemson University
• Original Assignee: Clemson University
• Inventors: Vyavahare, Naren, Tam, Hobey
• Primary Examiner(s): Crane, Lawrence E
• Application Number:
  US14/495,067
• Publication Number:
  US 20150087611A1
• Time in Patent Office: 1,126 Days
• CPC Class Codes: A01N 1/0231 Chemically defined matrices, e.g. alginate gels, for immobilising, holding or storing cells, tissue or organs for preservation purposes; Chemically altering or fixing cells, tissue or organs, e.g. by cross-linking, for preservation purposes
• CPC Class Codes: A61K 2300/00 Mixtures or combinations of active ingredients, wherein at least one active ingredient is fully defined in groups A61K31/00 - A61K41/00
• CPC Class Codes: A61K 31/15 Oximes (>C=N—O—); Hydrazines (>N—N<); Hydrazones (>N—N=) ; Imines (C—N=C)
• CPC Class Codes: A61K 31/17 having the group >N—C(O)—N< or >N—C(S)—N<, e.g. urea, thiourea, carmustine isoureas, isothioureas A61K31/155; sulfonylureas A61K31/64
• CPC Class Codes: A61K 31/7028 Compounds having saccharide radicals attached to non-saccharide compounds by glycosidic linkages
• CPC Class Codes: A61K 31/7036 having at least one amino group directly attached to the carbocyclic ring, e.g. streptomycin, gentamycin, amikacin, validamycin, fortimicins
• CPC Class Codes: A61K 35/34 Muscles; Smooth muscle cells; Heart; Cardiac stem cells; Myoblasts; Myocytes; Cardiomyocytes vascular smooth muscle A61K35/44
• CPC Class Codes: A61K 45/06 Mixtures of active ingredients without chemical characterisation, e.g. antiphlogistics and cardiaca

Abstract

A multi-step stabilization method for connective tissue is described. Stabilized tissues can exhibit increased resistance to degradation due to enzyme activity, fatigue and storage. The multi-step method includes a first step during which the tissue can be incubated with a glycosaminoglycanase inhibitor such as a sulfated oligosaccharide, one example of which being neomycin, a second step during which the tissue can be incubated with a crosslink activator such as a carbodiimide crosslink activator and/or a crosslinking agent such as a heterobifunctional crosslinking agent and/or a phenolic compound such as a tannin, examples of which include tannic acid and pentagalloylglucose, and a third step during which the tissue can be incubated with a second crosslink activator that can be the same or different as the first crosslink activator.

Claims

1. A method for stabilizing ex vivo or in vitro a cardiac/heart valve connective tissue comprising:

a first step including contacting the ex vivo or in vitro connective tissue with a neomycin trisulfate salt, the connective tissue including collagen, elastin, and one or more glycosaminoglycans;

a second step carried out subsequent to the first step, the second step including contacting the ex vivo or in vitro connective tissue with a solution comprising a first carbodiimide crosslinking reagent and pentagalloylglucose;

a third step carried out subsequent to the second step, the third step including contacting the ex vivo or in vitro connective tissue with a second carbodiimide crosslinking reagent.

2. The method of claim 1, wherein the ex vivo or in vitro connective tissue comprises a heart valve leaflet.

3. The method of claim 1, wherein the neomycin trisulfate salt is provided at a concentration of about 0.2 mM or greater.

4. The method of claim 1, wherein the contact of the first step is carried out for a period of time of about 30 minutes or more.

5. The method of claim 1, wherein the first carbodiimide crosslinking reagent comprises 1-ethyl-3-(3 dimethyl-aminopropyl) carbodiimide.

6. The method of claim 5, the solution comprising the first carbodiimide crosslinking reagent and pentagalloylglucose further comprising N-hydroxysuccinimide.

7. The method of claim 1, wherein the first carbodiimide crosslinking reagent is provided at a concentration of about 10 millimolar or greater.

8. The method of claim 1, wherein the solution comprises the pentagalloylglucose at a concentration of about 3 millimolar or greater.

9. The method of claim 1, wherein the contact of the second step is carried out for a period of time of about 12 hours or more.

10. The method of claim 1, wherein the second carbodiimide crosslinking reagent is the same as the first carbodiimide crosslinking reagent.

11. The method of claim 1, wherein the second carbodiimide crosslinking reagent comprises 1-ethyl-3-(3 dimethyl-aminopropyl) carbodiimide.

12. The method of claim 1, wherein the second carbodiimide-crosslinking reagent is provided at a concentration of about 10 millimolar or greater.

13. The method of claim 1, wherein the contact of the third step is carried out for a period of time of about 12 hours or more.

14. A stabilized ex vivo or in vitro connective heart valve tissue comprising a neomycin trisulfate salt and a pentagalloylglucose.

15. The stabilized ex vivo or in vitro connective tissue of claim 14, the tissue having a glycosaminoglycan concentration of greater than about 150 micrograms per 10 milligrams of the tissue.

16. The stabilized connective tissue of claim 14, wherein the tissue is a component of a bioprosthetic implant.

17. The stabilized connective tissue of claim 16, wherein the bioprosthetic implant is a heart component implant.

18. The stabilized connective tissue of claim 17, wherein the heart component implant is a bioprosthetic heart valve.