Rehydratable thiolated polysaccharide particles and sponge

• US 9,198,997 B2
• Filed: 04/23/2009
• Issued: 12/01/2015
• Est. Priority Date: 04/24/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Myntti, Matthew Franco, Oliver, Dana A., Vaccaro, Brian
• Primary Examiner(s): SHOMER, ISAAC
• Application Number:
  US12/429,120
• Publication Number:
  US 20090285897A1
• Time in Patent Office: 2,413 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61L 24/0031 Hydrogels or hydrocolloids
• CPC Class Codes: A61L 24/0036 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 24/08 Polysaccharides A61L24/043 takes precedence
• CPC Class Codes: A61L 26/0023 Polysaccharides
• CPC Class Codes: A61L 26/008 Hydrogels or hydrocolloids
• CPC Class Codes: A61P 17/02 for treating wounds, ulcers, burns, scars, keloids, or the like
• CPC Class Codes: C08B 37/003 Chitin, i.e. 2-acetamido-2-deoxy-(beta-1,4)-D-glucan or N-acetyl-beta-1,4-D-glucosamine; Chitosan, i.e. deacetylated product of chitin or (beta-1,4)-D-glucosamine; Derivatives thereof
• CPC Class Codes: C08G 2210/00 Compositions for preparing hydrogels
• CPC Class Codes: C08L 1/286 substituted with acid radicals, e.g. carboxymethyl cellulose [CMC] C08L1/282 takes precedence
• CPC Class Codes: C08L 101/02 characterised by the presence of specified groups , e.g. terminal or pendant functional groups
• CPC Class Codes: C08L 3/02 Starch; Degradation products thereof, e.g. dextrin
• CPC Class Codes: C08L 5/00 Compositions of polysaccharides or of their derivatives not provided for in groups C08L1/00 or C08L3/00
• CPC Class Codes: C08L 5/02 Dextran; Derivatives thereof
• CPC Class Codes: C08L 5/04 Alginic acid; Derivatives thereof
• CPC Class Codes: C08L 5/08 Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof
• CPC Class Codes: C08L 5/12 Agar or agar-agar , i.e. mixture of agarose and agaropectin; Derivatives thereof

Abstract

Tissue and other body structures may be protected using a hydrated composition made from free-flowing rehydratable particles or a rehydratable sponge comprising substantially collagen-free dehydrothermally crosslinked thiolated polysaccharide. Rehydration of crosslinked or uncrosslinked polysaccharide particles may be carried out without clumping by dispersing the particles in a biocompatible water-miscible polar dispersant such as ethanol and combining the dispersion with sufficient aqueous solvent for the particles to convert them to a cohesive hydrogel. The hydrated particles or sponge may assist in returning an injured, inflamed or surgically repaired surface to a normal state, e.g., through one or more healing mechanisms such as modulation of an inflammatory response, phagocytosis, mucosal remodeling, reciliation or other full or partial restoration of normal function.

Claims

1. A composition comprising free-flowing rehydratable particles of substantially collagen-free dehydrothermally crosslinked thiolated polysaccharide, the particles forming a gel when rehydrated.

2. A composition according to claim 1 wherein the particles contain substantially single polysaccharide.

3. A composition according to claim 1 wherein the particles comprise a blend of particles of two or more polysaccharides at least one of which is a thiolated polysaccharide.

4. A composition according to claim 1 wherein the thiolated polysaccharide comprises thiolated chitosan.

5. A composition according to claim 1 wherein the particles comprise thiolated chitosan particles and particles of another polysaccharide.

6. A composition according to claim 1 wherein the thiolated polysaccharide comprises thiolated agar, alginate, carrageenan, cellulose, chitin, chondroitin sulfate, dextran, galactomannan, glycogen, hyaluronic acid, starch or mixture thereof.

7. A composition according to claim 1 further comprising agar, alginate, carrageenan, cellulose, chitin, chondroitin sulfate, dextran, galactomannan, glycogen, hyaluronic acid, starch or mixture thereof.

8. A composition according to claim 1 further comprising carboxymethylcellulose.

9. A composition according to claim 1 further comprising a sealed syringe with which the particles can be rehydrated and dispensed.

17. A method for converting the composition of claim 1 to a gel, which method comprises:

a) dispersing free-flowing rehydratable, substantially collagen-free dehydratothermally crosslinked thiolated polysaccharide particles in a biocompatible water-miscible polar dispersant, and

b) combining the resulting dispersion with sufficient aqueous solvent for the particles to convert them to a cohesive hydrogel.

10. An implantable article comprising a rehydratable porous sponge comprising substantially collagen-free dehydrothermally crosslinked tiolated polysaccharide.

11. A method for making a polysaccharide gel-forming composition, which method comprises:

a) providing a substantially collagen-free polysaccharide solution comprising thiolated polysaccharide;

b) drying the solution to form a powder, and

c) dehydrothermally crosslinking the powder to form free-flowing particles that will provide a gel comprising thiolated polysaccharide when rehydrated.

12. A method for making an implantable article, which method comprises:

a) providing a substantially collagen-free polysaccharide solution comprising thiolated polysaccharide,

b) lyophilizing the solution to form a dried porous sponge, and

c) dehydrothermally crosslinking the sponge, thereby forming an implantable article which will form a sponge comprising thiolated polysaccharide when rehydrated.

13. A method comprising applying a gel or sponge comprising rehydrated substantially collagen-free dehydrothermally crosslinked thiolated polysaccharide to a body structure.

14. The method of claim 13, wherein the body structure is selected from the group consisting of mucosal tissue, cartilage, and bone.

15. The method of claim 14, wherein the body structure is mucosal tissue.

16. The method of claim 13, wherein the rehydrated gel is protective.