Medical device with multiple coating layers

• US 20050107870A1
• Filed: 08/20/2004
• Published: 05/19/2005
• Est. Priority Date: 04/08/2003
• Status: Abandoned Application

• Current Assignee: Biophan Technologies Incorporated
• Original Assignee: Biophan Technologies Incorporated
• Inventors: Wang, Xingwu, Greenwald, Howard J.
• Application Number:
  US10/923,579
• Publication Number:
  US 20050107870A1
• Time in Patent Office: Days
• US Class Current: 623/1.440
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61L 2300/608 having two or more layers
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• CPC Class Codes: A61L 31/18 Materials at least partially X-ray or laser opaque
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance

Abstract

An implantable medical device that contains two coating layers disposed above at least one of its surfaces. The first coating layer contains a biologically active material; and the second coating layer contains a polymeric material and nanomagnetic material disposed on the first coating layer; the second coating layer is substantially free of the biologically active material. The nanomagentic material has a saturation magentization of from about 2 to about 3000 electromagnetic units per cubic centimeter, and it contains nanomagnetic particleswith an average particle size of less than about 100 nanometers; the average coherence length between adjacent nanomagnetic particles is less than 100 nanometers.

Claims

1. A medical device that is insertable into the body of a patient comprising:

(a) a surface;

(b) a first coating layer comprising a biologically active material disposed on at least a portion of the surface; and

(c) a second coating layer comprising a polymeric material and nanomagnetic material disposed on the first coating layer, wherein the second coating layer is substantially free of the biologically active material, wherein;

said nanomagnetic material has a saturation magentization of from about 2 to about 3000 electromagnetic units per cubic centimeter, wherein said nanomagnetic material is comprised of nanomagnetic particles with an average particle size of less than about 100 nanometers, and wherein the average coherence length between adjacent nanomagnetic particles is less than 100 nanometers.

2. The medical device as recited in claim 1, wherein said nanomagnetic material has an average particle size of less than about 20 nanometers and a phase transition temperature of less than about 200 degrees Celsius.

3. The medical device as recited in claim 1, wherein said medical device further comprises a cytotoxic radioactive material.

4. The medical device as recited in claim 1, wherein said medical device is comprised of a material that is absorbable in living tissue.

5. The medical device as recited in claim 4, wherein said material that is absorbable in living tissue is selected from the group consisting of polyester amides from glycolic acids, polyester amides from lactic acids, polymers and copolymers of gylcolate, polymers and copolymers of lactate, and polydioxanone.

6. The medical device as recited in claim 1, wherein the average particle size of such nanomagnetic particles is less than about 15 nanometers.

7. The medical device as recited in claim 1, wherein said nanomagentic material has a saturation magnetization of at least 2,000 electromagnetic units per cubic centimeter.

8. The medical device as recited in claim 1, wherein said nanomagnetic material has a saturation magnetization of at least 2,500 electromagnetic units per cubic centimeter.

9. The medical device as recited in claim 1, wherein said particles of said nanomagnetic material have a squareness of from about 0.05 to about 1.0.

10. The medical device as recited in claim 1, wherein said particles of said nanomagnetic material are at least triatomic, being comprised of a first distinct atom, a second distinct atom, and a third distinct atom.

11. The medical device as recited in claim 10, wherein said first distinct atom is an atom selected from the group consisting of atoms of actinium, americium, berkelium, californium, cerium, chromium, cobalt, curium, dysprosium, einsteinium, erbium, europium, fermium, gadolinium, holmium, iron, lanthanum, lawrencium, lutetium, manganese, mendelevium, nickel, neodymium, neptunium, nobelium, plutonium, praseodymium, promethium, protactinium, samarium, terbium, thorium, thulium, uranium, and ytterbium, and mixtures thereof.

12. The medical device as recited in claim 10, wherein said first distinct atom is a cobalt atom.

13. The medical device as recited in claim 11, wherein said particles of nanomagnetic material are comprised of atoms of cobalt and atoms of iron.

14. The medical device as recited in claim 11, wherein said first distinct atom is a radioactive cobalt atom.

15. The medical device as recited in claim 10, wherein said particles of nanomagnetic material are comprised of a said first distinct atom, said second distinct atom, said third distinct atom, and a fourth distinct atom.

16. The medical device as recited in claim 15, wherein said particles of nanomagnetic material are comprised of a fifth distinct atom.

17. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a squareness of from about 0.1 to about 0.9.

18. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a squareness is from about 0.2 to about 0.8.

19. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have an average size of less of less than about 3 nanometers.

20. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have an average size of less than about 15 nanometers.

21. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have an average size is less than about 11 nanometers.

22. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a phase transition temperature of less than 46 degrees Celsius.

23. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a phase transition temperature of less than about 50 degrees Celsius.

24. The medical device as recited in claim 1, wherein said nanomagnetic material has a coercive force of from about 0.1 to about 10 Oersteds.

25. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a relative magnetic permeability of from about 1.5 to about 2,000.

26. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a saturation magnetization of at least 100 electromagnetic units per cubic centimeter.

27. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a saturation magnetization of at least about 200 electromagnetic units (emu) per cubic centimeter.

28. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a saturation magnetization of at least about 1,000 electromagnetic units per cubic centimeter.

29. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a coercive force of from about 0.01 to about 5,000 Oersteds.

30. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a coercive force of from about 0.01 to about 3,000 Oersteds.

31. The medical device as recited in claim 1, wherein said particles of nanomagnetic material are disposed within a film that has a heat shielding factor of at least 0.2.

32. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a relative magnetic permeability of from about 1 to about 500,000.

33. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a relative magnetic permeability of from about 1.5 to about 260,000.

34. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a mass density of at least about 0.001 grams per cubic centimeter.

35. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a mass density of at least about 1 gram per cubic centimeter.

36. The medical device as recited in claim 1, wherein said particles of nanomagnetic material have a mass density of at least about 3 grams per cubic centimeter.

37. The medical device as recited in claim 1 wherein said particles of nanomagnetic material have a mass density of at least about 4 grams per cubic centimeter.

38. The medical device as recited in claim 15, wherein said second distinct atom has a relative magnetic permeability of about 1.0.

39. The medical device as recited in claim 38, wherein said second distinct atom is an atom selected from the group consisting of aluminum, antimony, barium, beryllium, boron, bismuth, calcium, gallium, germanium, gold, indium, lead, magnesium, palladium, platinum, silicon, silver, strontium, tantalum, tin, titanium, tungsten, yttrium, zirconium, magnesium, and zinc.

40. The medical device as recited in claim 39, wherein said third distinct atom is an atom selected from the group consisting of argon, bromine, carbon, chlorine, fluorine, helium, hydrogen, iodine, krypton, oxygen, neon, nitrogen, phosphorus, sulfur, and xenon.

41. The medical device as recited in claim 40, wherein said third distinct atom is nitrogen.

42. The medical device as recited in claim 41, wherein said nanomagnetic particles are represented by the formula A_xB_yC_z, wherein A is said first distinct atom, B is said second distinct atom, C is said third distinct atom, and x+y+z is equal to 1.

43. The medical device as recited in claim 42, wherein said nanomagnetic particles are comprised of atoms of oxygen.

44. The medical device as recited in claim 43, wherein said nanomagnetic particles are comprised of atoms of iron.

45. The medical device as recited in claim 44, wherein said atoms of iron are atoms of radioactive iron.

46. The medical device as recited in claim 44, wherein nanomagnetic particles are comprised of atoms of cobalt.

47. The medical device as recited in claim 46, wherein said atoms of cobalt are atoms of radioactive cobalt.

48. The medical device as recited in claim 1, wherein said particles of nanomagnetic material are present in the form of a coating with a thickness of from about 400 to about 2000 nanometers.

49. The medical device as recited in claim 48, wherein said coating has a thickness of from about 600 to about 1200 nanometers.

50. The medical device as recited in claim 49, wherein said coating has a morphological density of at least about 98 percent.

51. The medical device as recited in claim 50, wherein said coating has a morphological density of at least about 99 percent.

52. The medical device as recited in claim 51, wherein said coating has a morphological density of at least about 99.5 percent.

53. The medical device as recited in claim 49, wherein said coating has an average surface roughness of less than about 100 nanometers.

54. The medical device as recited in claim 49, wherein said coating has an average surface roughness of less than about 10 nanometers.

55. The medical device as recited in claim 1, wherein said coating is biocompatible.

56. The medical device as recited in claim 1, wherein said coating is hydrophobic.

57. The medical device as recited in claim 1, wherein said coating is hydrophilic.

58. The medical device of claim 1, wherein the first coating layer is substantially free of said magnetic particles.

59. The medical device as recited in claim 1 wherein the first coating layer further comprises a polymeric material.

60. The medical device as recited in claim 55, wherein the polymeric material in the first coating layer is different than the polymeric material in the second coating layer.

61. The medical device as recited in claim 1, further comprising a sealing layer disposed on the second coating layers wherein the sealing layer comprises a polymeric material and is substantially free of the biologically active material and the magnetic particles.

62. The medical device as recited in claim 1, wherein the medical device is a stent having a sidewall comprising a plurality of struts, and wherein the surface is a part of the struts.