Block copolymer particles

• US 7,947,368 B2
• Filed: 02/15/2006
• Issued: 05/24/2011
• Est. Priority Date: 12/21/2005
• Status: Expired due to Fees

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Inventors: Song, Young-Ho
• Primary Examiner(s): KILIMAN, LESZEK B
• Application Number:
  US11/355,301
• Publication Number:
  US 20070141340A1
• Time in Patent Office: 1,924 Days
• Field of Search: 428402-407, 427/212
• US Class Current: 428/402
• CPC Class Codes: C08F 293/005 using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent
• CPC Class Codes: C08F 297/00 Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer
• CPC Class Codes: C08F 297/02 using a catalyst of the anionic type
• CPC Class Codes: C08F 297/04 polymerising vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C09D 153/00 Coating compositions based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C09D 153/02 Vinyl aromatic monomers and conjugated dienes
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]
• CPC Class Codes: Y10T 428/2991 Coated
• CPC Class Codes: Y10T 428/2993 Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]
• CPC Class Codes: Y10T 428/2995 Silane, siloxane or silicone coating
• CPC Class Codes: Y10T 428/2996 Glass particles or spheres
• CPC Class Codes: Y10T 428/2998 including synthetic resin or polymer

Abstract

Block copolymer particles, and related compositions and methods, are disclosed.

Claims

1. A particle comprising a block copolymer and having at least one pore, wherein the particle has a diameter that is about one micron or more and about 3,000 microns or less, the block copolymer includes at least one first block having a glass transition temperature of at most 37°

C. and at least one second block having a glass transition temperature of greater than 37°

C.

2. The particle of claim 1, wherein the particle further comprises a therapeutic agent.

3. The particle of claim 1, wherein the at least one first block comprises at least one polyolefin block.

4. The particle of claim 1, wherein the at least one first block comprises at least one isobutylene monomer.

5. The particle of claim 1, wherein the at least one second block comprises at least one block selected from the group consisting of vinyl aromatic blocks, methacrylate blocks, and combinations thereof.

6. The particle of claim 1, wherein the at least one first block comprises at least one isobutylene monomer and the at least one second block comprises at least one monomer selected from the group consisting of styrene, α

-methylstyrene, and combinations thereof.

7. The particle of claim 1, wherein the block copolymer has the formula X-(AB)_n, A is a polyolefin block, B is a vinyl aromatic block or a methacrylate block, n is a positive whole number, and X is an initiator.

8. The particle of claim 1, wherein the block copolymer has the formula BAB or ABA, in which A is a first block and B is a second block.

9. The particle of claim 1, wherein the block copolymer has the formula B(AB)_n or A(BA)_n, in which A is a first block, B is a second block, and n is a positive whole number.

10. The particle of claim 1, wherein the block copolymer forms a coating on the particle.

11. The particle of claim 1, wherein the block copolymer comprises styrene-isobutylene-styrene.

12. A method of making a first particle comprising a block copolymer and having at least one pore, the method comprising:

generating a drop comprising the block copolymer and at least one member selected from the group consisting of salts, water-soluble polymers, bases, and combinations thereof and

forming the drop into the first particle comprising the block copolymer and having the at least one pore,

wherein;

the method comprises generating the drop comprising the block copolymer and the salt,

the salt comprises at least one salt selected from the group consisting of sodium chloride, calcium chloride, and sodium bicarbonate, and

the block copolymer includes at least one first block having a glass transition temperature of at most 37°

C. and at least one second block having a glass transition temperature of greater than 37°

C.

13. The method of claim 12, wherein forming the drop into the first particle comprises contacting the drop with a solution comprising water.

14. The method of claim 12, wherein the method comprises generating the drop comprising the block copolymer and a salt, and forming the drop into the first particle comprises dissolving the salt.

15. The method of claim 12, wherein the block copolymer comprises styrene-isobutylene-styrene.

16. The method of claim 12, wherein the method comprises generating the drop comprising the block copolymer and the water-soluble polymer, and the water-soluble polymer comprises at least one polymer selected from the group consisting of polyethylene glycol, polyvinylpyrrolidone, carboxymethylcellulose, and hydroxyethylcellulose.

17. The method of claim 16, wherein the block copolymer includes at least one first block having a glass transition temperature of at most 37°

C. and at least one second block having a glass transition temperature of greater than 37°

C.

18. The method of claim 17, wherein the block copolymer comprises styrene-isobutylene styrene.

19. The method of claim 12, wherein forming the drop into the first particle comprises contacting the drop with an acid.

20. The method of claim 19, wherein the acid comprises at least one acid selected from the group consisting of citric acid, acetic acid, and hydrochloric acid.

21. The method of claim 19, wherein contacting the drop with an acid comprises generating a gas.

22. The method of claim 21, wherein the gas comprises at least one gas selected from the group consisting of carbon dioxide, ammonia, and combinations thereof.

23. The method of claim 12, wherein the method comprises generating the drop comprising the block copolymer and a base, and the base comprises at least one base selected from the group consisting of sodium bicarbonate, ammonium bicarbonate, and potassium bicarbonate.

24. The method of claim 23, wherein the block copolymer includes at least one first block having a glass transition temperature of at most 37°

C. and at least one second block having a glass transition temperature of greater than 37°

C.

25. The method of claim 24, wherein forming the drop into the first particle comprises contacting the drop with an acid.

26. A method of making a particle comprising a block copolymer and having at least one pore, the method comprising:

forming a drop comprising the block copolymer and a solvent; and

removing some or all of the solvent from the drop to form the particle comprising the block copolymer and having the at least one pore,

wherein;

removing some or all of the solvent from the drop comprises exposing the drop to an atmosphere having a pressure of less than 30 inches Hg,

removing some or all of the solvent from the drop comprises exposing the drop to a temperature of at least about 40°

C., and

the block copolymer includes at least one first block having a glass transition temperature of at most 37°

C. and at least one second block having a glass transition temperature of greater than 37°

C.

27. The method of claim 26, wherein the block copolymer comprises styrene-isobutylene-styrene.

28. The method of claim 26, wherein removing some or all of the solvent from the drop comprises exposing the drop to a temperature of at least about 40°

C.