Porous polymeric particle comprising polyvinyl alcohol and having interior to surface porosity-gradient

• US 7,449,236 B2
• Filed: 08/08/2003
• Issued: 11/11/2008
• Est. Priority Date: 08/09/2002
• Status: Expired due to Fees

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Casey, Thomas V. II, Lanphere, Janel L., Kapoglis, Greg, Pierre, Ernest J.
• Primary Examiner(s): LE, HOA T
• Application Number:
  US10/637,130
• Publication Number:
  US 20040096662A1
• Time in Patent Office: 1,922 Days
• Field of Search: 428/402, 428/212, 428/218, 428/403, 428/407, 424/489, 424/493, 424/501, 514/951, 514/964
• US Class Current: 428/402
• CPC Class Codes: A61F 2/0036 implantable A61F2/0018 takes precedence
• CPC Class Codes: A61K 49/0452 Solutions, e.g. for injection
• CPC Class Codes: A61K 9/1635 obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polyvinyl pyrrolidone, poly(meth)acrylates
• CPC Class Codes: A61K 9/1652 Polysaccharides, e.g. alginate, cellulose derivatives; Cyclodextrin homeopathic globules A61K9/1623
• CPC Class Codes: A61L 24/001 Use of materials characterised by their function or physical properties
• CPC Class Codes: A61L 24/0036 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 24/06 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L24/043, A61L24/046 take precedence
• CPC Class Codes: A61L 2430/36 for embolization or occlusion, e.g. vaso-occlusive compositions or devices artificial blood vessels A61L27/507
• CPC Class Codes: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/50 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 takes precedence
• CPC Class Codes: C08J 2305/00 Characterised by the use of polysaccharides or of their derivatives not provided for in groups C08J2301/00 or C08J2303/00
• CPC Class Codes: C08J 3/12 Powdering or granulating
• CPC Class Codes: C08J 3/24 Crosslinking, e.g. vulcanising, of macromolecules mechanical aspects B29C35/00; crosslinking agents C08K
• CPC Class Codes: C08L 29/04 Polyvinyl alcohol; Partially hydrolysed homopolymers or copolymers of esters of unsaturated alcohols with saturated carboxylic acids
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

Embolic particles, as well as their methods of use and manufacture, are described.

Claims

1. A polymeric particle comprising a polyvinyl alcohol and having a diameter of about 500 microns or less, wherein the particle has a first density of pores in an interior region and a second density of pores at a surface region, the first density being different from the second density, and wherein the particle has a first average pore size in the interior region and a second average pore size at the surface region, the first average pore size being greater than the second average pore size.

2. The polymeric particle of claim 1, wherein the second density is greater than the first density.

3. The polymeric particle of claim 1, wherein the particle has a diameter of about 10 microns or more.

4. The polymeric particle of claim 1, wherein the particle has a diameter of about 100 microns or more.

5. The polymeric particle of claim 4, wherein the particle has a diameter of about 300 microns or less.

6. The polymeric particle of claim 1, wherein the particle has a diameter of about 300 microns or more.

7. The polymeric particle of claim 1, wherein the particle is at least partially coated with a substantially bioabsorbable material.

8. The polymeric particle of claim 1, wherein the particle has a density of from about 1.1 grams per cubic centimeter to about 1.4 grams per cubic centimeter.

9. The polymeric particle of claim 1, wherein the particle has a sphericity of about 0.9 or more.

10. The polymeric particle of claim 1, wherein, after compression to about 50 percent, the particle has a sphericity of about 0.9 or more.

11. The polymeric particle of claim 1, wherein the particle comprises about 2.5 weight percent or less polysaccharide.

12. The polymeric particle of claim 11, wherein the polysaccharide comprises alginate.

13. The polymeric particle of claim 12, wherein the alginate has a guluronic acid content of about 60 percent or greater.

14. The polymeric particle of claim 1, wherein the particle is substantially insoluble in DMSO.

15. The polymeric particle of claim 1, wherein the particle is substantially free of animal-derived compounds.

16. A polymeric particle comprising a polyvinyl alcohol and having a diameter of about 500 microns or less, wherein the particle has a first average pore size in an interior region and a second average pore size at a surface region, the first average pore size being greater than the second average pore size.

17. The polymeric particle of claim 16, wherein the particle has a diameter of about 10 microns or more.

18. The polymeric particle of claim 16, wherein the particle has a diameter of about 100 microns or more.

19. The polymeric particle of claim 18, wherein the particle has a diameter of about 300 microns or less.

20. The polymeric particle of claim 16, wherein the particle has a diameter of about 300 microns or more.

21. The polymeric particle of claim 16, wherein the particle comprises about 2.5 weight percent or less polysaccharide.

22. The polymeric particle of claim 21, wherein the polysaccharide comprises alginate.

23. A composition, comprising:

a plurality of particles, at least some of the plurality of particles comprising a polyvinyl alcohol and having a diameter of about 500 microns or less, wherein at least some of the particles having a diameter of about 500 microns or less have a first density of pores and a first average pore size in an interior region and a second density of pores and a second average pore size at a surface region, the first density being different from the second density, and the first average pore size being greater than the second average pore size; and

a carrier fluid, the plurality of particles being in the carrier fluid.

24. The composition of claim 23, wherein the carrier fluid comprises a saline solution.

25. The composition of claim 23, wherein the carrier fluid comprises a contrast agent.

26. The composition of claim 23, wherein the plurality of particles has a mean diameter of about 500 microns or less.

27. The composition of claim 23, wherein the plurality of particles has a mean diameter of about 10 microns or more.

28. The composition of claim 23, wherein the plurality of particles has a mean diameter of about 100 microns or more.

29. The composition of claim 28, wherein the plurality of particles has a mean diameter of about 300 microns or less.

30. The composition of claim 23, wherein the plurality of particle has a mean diameter of about 300 microns or more.

31. A composition, comprising:

a plurality of particles, at least some of the plurality of particles comprising a polyvinyl alcohol and having a diameter of about 500 microns or less, wherein at least some of the particles having a diameter of about 500 microns or less have a first average pore size in an interior region and a second average pore size at a surface region, the first average pore size being greater than the second average pore size; and

a carrier fluid, the plurality of particles being in the carrier fluid.

32. The composition of claim 31, wherein the plurality of particles has a mean diameter of about 500 microns or less.

33. The composition of claim 31, wherein the plurality of particles has a mean diameter of about 10 microns or more.

34. The composition of claim 31, wherein the plurality of particles has a mean diameter of about 100 microns or more.

35. The composition of claim 34, wherein the plurality of particles has a mean diameter of about 300 microns or less.

36. The composition of claim 31, wherein the plurality of particle has a mean diameter of about 300 microns or more.

37. A polymeric particle comprising a polysaccharide and having a diameter of about 500 microns or less, wherein the particle has an interior region defining pores and a surface region defining pores, the particle has a first density of pores in the interior region and a second density of pores at the surface region, the first density being different from the second density, and the particle has a first average pore size in the interior region and a second average pore size at the surface region, the first average pore size being greater than the second average pore size.

38. The polymeric particle of claim 37, wherein the particle has a diameter of about 10 microns or more.

39. The polymeric particle of claim 37, wherein the particle has a diameter of about 100 microns or more.

40. The polymeric particle of claim 39, wherein the particle has a diameter of about 300 microns or less.

41. The polymeric particle of claim 37, wherein the particle has a diameter of about 300 microns or more.

42. The polymeric particle of claim 37, wherein the particle comprises about 2.5 weight percent or less of the polysaccharide.

43. The polymeric particle of claim 42, wherein the polysaccharide comprises alginate.