Method for rehydrating polysaccharide particles
View Patent ↗Tissue and other body structures may be protected using a hydrated composition made from free-flowing substantially collagen-free rehydratable polysaccharide particles and rehydratable polysaccharide sponges. Rehydration of the particles without clumping may be carried out be 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 composition 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.
1. A method for converting a dry powdered composition to a gel, which method comprises:
a) dispersing free-flowing polysaccharide particles in a biocompatible water-miscible polar dispersant that is a sufficiently poor solvent for the particles so that the mixture of particles and dispersant will not form a true solution, and
b) combining the resulting dispersion with sufficient aqueous solvent for the particles to convert them to a cohesive hydrogel,
wherein the water-miscible polar dispersant comprises water, ethanol, isopropanol or acetone.
2. A method according to claim 1 wherein the water-miscible polar dispersant is water and the aqueous solvent for the particles is acidified water.
3. A method according to claim 1 wherein the water-miscible polar dispersant comprises ethanol.
4. A method according to claim 1 wherein the water-miscible polar dispersant comprises isopropanol or acetone.
5. A method according to claim 1 wherein the polysaccharide particles have been crosslinked.
6. A method according to claim 1 wherein the polysaccharide particles have been crosslinked using a separate crosslinking agent.
7. A method according to claim 1 wherein the polysaccharide particles are uncrosslinked.
8. A method according to claim 1 wherein the polysaccharide particles are substantially collagen-free.
9. A method according to claim 1 wherein the polysaccharide particles are substantially a single polysaccharide.
10. A method according to claim 1 wherein the polysaccharide particles are a blend of two or more polysaccharides.
11. A method according to claim 1 wherein the polysaccharide comprises cellulose, chitosan, agar, alginate, carrageenan, chitin, chondroitin sulfate, dextran, galactomannan, glycogen, hyaluronic acid, starch or mixture thereof.
12. A method according to claim 1 wherein the polysaccharide comprises an oxidized polysaccharide or salt.
13. A method according to claim 1 wherein the polysaccharide comprises carboxymethylcellulose.
14. A method according to claim 1 wherein the polysaccharide is substantially only carboxymethylcellulose.
15. A method according to claim 1 wherein the polysaccharide comprises chitosan.
16. A method according to claim 15 wherein the chitosan is unmodified.
17. A method according to claim 1 wherein the polysaccharide comprises a mixture of chitosan and another polysaccharide.
18. A method according to claim 1 wherein the polysaccharide comprises a mixture of carboxymethylcellulose and chitosan.
19. A method according to claim 1 comprising forming the cohesive hydrogel without visible clumps of unhydrated polysaccharide.
20. A method according to claim 1 further comprising injecting or spraying a layer of the cohesive hydrogel onto mucosal tissue.
21. A method according to claim 1 further comprising injecting or spraying the cohesive hydrogel into an opening, recess, passageway or joint in a limb.
22. A method according to claim 1 further comprising injecting or spraying the cohesive hydrogel into an opening, recess, passageway or joint in a spinal column.
23. A method for converting a dry powdered composition to a gel, which method comprises:
a) dispersing free-flowing 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,
wherein the polysaccharide particles have been dehydrothermally crosslinked.