Biodegradable particles for medical treatment and vascular embolization material

Patent metadata

Field	Value
Publication number	US-9408948-B2
Application number	US-201113995294-A
Country	US
Kind code	B2
Filing date	Dec 19, 2011
Priority date	Dec 20, 2010
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

Biodegradable particles for medical use and a vascular embolization material have improved flexibility, cause less aggregation among particles, and have improved particle shape-recovering ability after passing through a catheter or the like. The biodegradable particles for medical use are composed of an A1-B-A2 type triblock copolymer, wherein A1 and A2 are each a block of biodegradable copolymer constituted of monomers including glycolic acid, lactic acid and 6-hydroxycaproic acid, and B is a block of water-soluble polymer.

First claim

The invention claimed is:

1. Biodegradable particles for medical use composed of an A1-B-A2 type triblock copolymer, wherein:
A1 is a block of biodegradable copolymer constituted of monomers comprising glycolic acid, lactic acid and 6-hydroxycaproic acid,
A2 is a block of biodegradable copolymer constituted of monomers comprising glycolic acid, lactic acid and 6-hydroxycaproic acid,
B is a block of water-soluble polymer, and
a ratio of a structure originated from 6-hydroxycaproic acid in the blocks of biodegradable copolymer of A1 and A2 is 25 to 85%.

2. The biodegradable particles according to claim 1 , which have a compressive load of not more than 0.1 N and a compression recovery ratio of not less than 80% in the water-saturated state.

3. The biodegradable particles according to claim 2 , wherein in said block of biodegradable copolymer, the ratio of the structure originated from glycolic acid is 10 to 30%.

4. The biodegradable particles according to claim 2 , wherein in said block of biodegradable copolymer, the ratio of the structure originated from lactic acid with respect to a structure originated from glycolic acid is not less than 50%.

5. The biodegradable particles according to claim 1 , wherein in said block of biodegradable copolymer, the ratio of the structure originated from glycolic acid is 10 to 30%.

6. The biodegradable particles according to claim 5 , wherein in said block of biodegradable copolymer, the ratio of the structure originated from lactic acid with respect to a structure originated from glycolic acid is not less than 50%.

7. The biodegradable particles according to claim 2 , wherein in said block of biodegradable copolymer, the ratio of a structure originated from lactic acid is not more than 65%.

8. The biodegradable particles according to claim 5 , wherein in said block of biodegradable copolymer, the ratio of a structure originated from lactic acid is not more than 65%.

9. The biodegradable particles according to claim 1 , wherein weight-average molecular weight of said triblock copolymer is 3000 to 100000.

10. The biodegradable particles according to claim 1 , wherein weight-average molecular weight of said block of water-soluble polymer is 200 to 50000.

11. The biodegradable particles according to claim 1 , wherein said water-soluble polymer is polyethylene glycol.

12. The biodegradable particles according to claim 1 , whose average particle diameter is 20 to 2000 μm.

13. The biodegradable particles according to claim 1 , whose particle diameter distribution is within an average particle diameter±100 μm.

14. A vascular embolization material composed of the biodegradable particles for medical use according to claim 1 .

15. Biodegradable particles for medical use composed of an A1-B-A2 type triblock copolymer, wherein:
A1 is a block of biodegradable copolymer constituted of monomers comprising glycolic acid, lactic acid and 6-hydroxycaproic acid,
A2 is a block of biodegradable copolymer constituted of monomers comprising glycolic acid, lactic acid and 6-hydroxycaproic acid,
B is a block of water-soluble polymer,
wherein in said blocks of biodegradable copolymer of A1 and A2, the ratio of a structure originated from lactic acid is not more than 65%, and
wherein in said block of biodegradable copolymer, a ratio of a structure originated from lactic acid with respect to a structure originated from glycolic acid is not less than 50%.

16. Biodegradable particles for medical use composed of an A1-B-A2 type triblock copolymer, wherein:
A1 is a block of biodegradable copolymer constituted of monomers comprising glycolic acid, lactic acid and 6-hydroxycaproic acid,
A2 is a block of biodegradable copolymer constituted of monomers comprising glycolic acid, lactic acid and 6-hydroxycaproic acid,
B is a block of water-soluble polymer,
wherein in said blocks of biodegradable copolymer of A1 and A2, the ratio of a structure originated from lactic acid is not more than 65%, and
a ratio of a structure originated from 6-hydroxycaproic acid in the block of biodegradable copolymer is 25 to 85%.

Assignees

• Yamamura Yasufumi
• Tanahashi Kazuhiro
• Nakanishi Megumi
• Fujita Masaki
• Toray Industries

Inventors

• Yamamura Yasufumi
• Tanahashi Kazuhiro
• Nakanishi Megumi
• Fujita Masaki

Classifications

• C08G63/664 Primary

  derived from hydroxy carboxylic acids · CPC title

• A61P35/00

  Antineoplastic agents · CPC title

• Y10T428/2982

  Particulate matter [e.g., sphere, flake, etc.] · CPC title

• A61L2430/36

  for embolization or occlusion, e.g. vaso-occlusive compositions or devices · CPC title

• A61L24/0042

  Materials resorbable by the body · CPC title