BIORESORBABLE EMBOLIZATION MICROSPHERES

• US 20110082427A1
• Filed: 10/06/2010
• Published: 04/07/2011
• Est. Priority Date: 10/06/2009
• Status: Active Grant

• Current Assignee: Regents of The University of Minnesota (University of Minnesota)
• Original Assignee: Regents of The University of Minnesota (University of Minnesota)
• Inventors: Golzarian, Jafar, Weng, Lihui
• Granted Patent: US 8,617,132 B2
• Time in Patent Office: Days
• US Class Current: 604/187
• CPC Class Codes: A61L 2300/406 Antibiotics
• CPC Class Codes: A61L 2300/622 Microcapsules
• CPC Class Codes: A61L 24/0015 Medicaments; Biocides
• CPC Class Codes: A61L 24/08 Polysaccharides A61L24/043 takes precedence
• CPC Class Codes: A61L 2430/36 for embolization or occlusion, e.g. vaso-occlusive compositions or devices
• CPC Class Codes: A61P 35/00 Antineoplastic agents
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system
• CPC Class Codes: C08L 1/28 Alkyl ethers
• CPC Class Codes: C08L 5/08 Chitin; Chondroitin sulfate; Hyaluronic acid; Derivatives thereof
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

The present disclosure is generally directed to an embolic material which, in some embodiments, may be in the form of a microsphere or a plurality of microspheres. The embolic material generally comprises carboxymethyl chitosan (CCN) crosslinked with carboxymethyl cellulose (CMC). In some embodiments, the embolic material may further comprise a therapeutic agent, such as doxorubicin.

Claims

1. An embolic material comprising:

a microsphere comprising a diameter between about 50 micrometers and about 2200 micrometers,

wherein the microsphere comprises carboxymethyl chitosan crosslinked with carboxymethyl cellulose.

2. The embolic material of claim 1, wherein the microsphere comprises a diameter between about 1600 micrometers and about 2000 micrometers.

3. The embolic material of claim 1, wherein the microsphere comprises a diameter of between about 500 micrometers and about 700 micrometers.

4. The embolic material of claim 1, wherein the microsphere further comprises a therapeutic agent.

5. The embolic material of claim 4, wherein the therapeutic agent comprises doxorubicin.

6. The embolic material of claim 1, wherein the microsphere is substantially free of a small molecule crosslinking agent.

7. The embolic material of claim 1, wherein the microsphere is compressible.

8. The embolic material of claim 7, wherein the microsphere has a fracture strain of between about 70% and about 90%.

9. An embolization suspension comprising:

a solvent; and

a plurality of microspheres suspended in the solvent, wherein at least one of the plurality of microspheres comprises a diameter between about 50 micrometers and about 2200 micrometers, and wherein at least one of the plurality of microspheres comprises carboxymethyl chitosan crosslinked with carboxymethyl cellulose.

10. The embolization suspension of claim 9, wherein the solvent comprises a mixture of contrast medium and saline.

11. The embolization suspension of claim 10, wherein the mixture comprises about 40 vol. % contrast medium and about 60 vol. % saline.

12. The embolization suspension of claim 9, wherein at least one of the plurality of microspheres comprises a diameter between about 1600 micrometers and about 2000 micrometers.

13. The embolization suspension of claim 9, wherein at least one of the plurality of microspheres comprises a diameter of between about 500 micrometers and about 700 micrometers.

14. The embolization suspension of claim 9, wherein at least one of the plurality of microspheres further comprises a therapeutic agent.

15. The embolization suspension of claim 14, wherein the therapeutic agent comprises doxorubicin.

16. The embolization suspension of claim 9, wherein at least one of the plurality of microspheres is substantially free of a small molecule crosslinking agent.

17. The embolization suspension of claim 9, wherein the microsphere is compressible.

18. The embolization suspension of claim 17, wherein the microsphere has a fracture strain of between about 70% and about 90%.

19. A kit comprising:

a plurality of microspheres, wherein at least one of the microspheres comprises a diameter between about 50 micrometers and about 2200 micrometers, and wherein at least one of the plurality of microspheres comprises carboxymethyl chitosan crosslinked with carboxymethyl cellulose; and

a syringe or vial in which the plurality of microspheres is disposed.

20. The kit of claim 19, further comprising a solvent disposed in a solvent container.

21. The kit of claim 20, wherein the solvent comprises a mixture of contrast and saline.

22. The kit suspension of claim 21, wherein the mixture comprises about 50 vol. % contrast and about 50 vol. % saline.

23. The kit of claim 19, wherein at least one of the plurality of microspheres comprises a diameter between about 1600 micrometers and about 2000 micrometers.

24. The kit of claim 19, wherein at least one of the plurality of microspheres comprises a diameter of between about 500 micrometers and about 700 micrometers.

25. The kit of claim 19, wherein at least one of the plurality of microspheres further comprises a therapeutic agent.

26. The kit of claim 25, wherein the therapeutic agent comprises doxorubicin.

27. The kit of claim 19, wherein at least one of the plurality of microspheres is substantially free of a small molecule crosslinking agent.

28. The kit of claim 19, wherein the at least one of the plurality of microspheres is compressible.

29. The kit of claim 28, wherein the at least one of the plurality of microspheres has a fracture strain of between about 70% and about 90%.

30. The kit of claim 19, further comprising a catheter and a guide wire.

31. A method of forming an embolic microsphere comprising:

at least partially oxidizing carboxymethyl cellulose (CMC) to form partially oxidized CMC;

forming an emulsion of partially oxidized CMC, carboxymethyl chitosan (CCN), water, and an oil; and

crosslinking the CCN with the CMC to form the embolic microsphere.

32. The method of claim 31, further comprising washing the embolic microsphere.

33. The method of claim 32, further comprising drying the embolic microsphere under a vacuum.

34. The method of claim 31, wherein crosslinking the CCN with the CMC to form the embolic microsphere comprises mixing the emulsion at a temperature of between about 20°

C. and 70°

C. for at least about 12 hours.

35. The method of claim 34, wherein crosslinking the CCN with the CMC to form the embolic microsphere comprises mixing the emulsion at a temperature of about 50°

C. for at least about 12 hours.

36. The method of claim 31, wherein crosslinking the CCN with the CMC to form the embolic microsphere comprises crosslinking the CCN with the CMC to form an embolic microsphere comprising a diameter between about 50 μ

m and about 2200 μ

m.

37. The method of claim 31, wherein crosslinking the CCN with the CMC to form the embolic microsphere comprises crosslinking the CCN with the CMC to form an embolic microsphere comprising a diameter between about 100 μ

m and about 1200 μ

m.

38. The method of claim 31, wherein crosslinking the CCN with the CMC to form the embolic microsphere comprises crosslinking the CCN with the CMC to form an embolic microsphere comprising a diameter between about 300 μ

m and about 500 μ

m.

39. The method of claim 31, wherein crosslinking the CCN with the CMC to form the embolic microsphere comprises crosslinking the CCN with the CMC to form an embolic microsphere comprising a diameter between about 500 μ

m and about 700 μ

m.

40. The method of claim 31, wherein crosslinking the CCN with the CMC to form the embolic microsphere comprises crosslinking the CCN with the CMC to form an embolic microsphere comprising a diameter of between about 1600 μ

m about 2000 μ

m.

41. A method comprising:

injecting an embolic microsphere comprising carboxymethyl chitosan crosslinked with carboxymethyl cellulose in a blood vessel of a patient to occlude an artery of the patient.

42. The method of claim 41, wherein injecting the embolic microsphere comprises:

disposing the embolic microsphere and a solvent in a syringe; and

injecting the embolic microsphere through a catheter in the blood vessel of the patient.

43. The method of claim 41, wherein the embolic microsphere further comprises a therapeutic agent.

44. The method of claim 43, wherein the therapeutic agent comprises doxorubicin.