Reduced temperature sterilization of stents

• US 20080010947A1
• Filed: 07/13/2006
• Published: 01/17/2008
• Est. Priority Date: 07/13/2006
• Status: Active Grant

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Castro, Daniel, Gale, David C., Huang, Bin, Freeman, Abigail
• Granted Patent: US 7,998,404 B2
• Time in Patent Office: Days
• US Class Current: 53/425
• CPC Class Codes: A61L 2/08 Radiation
• CPC Class Codes: A61L 2/081 Gamma radiation
• CPC Class Codes: A61L 2/082 X-rays
• CPC Class Codes: A61L 2/085 Infrared radiation
• CPC Class Codes: A61L 2/087 Particle radiation, e.g. electron-beam, alpha or beta radiation
• CPC Class Codes: A61L 2/10 Ultraviolet radiation
• CPC Class Codes: A61L 2202/23 Containers, e.g. vials, bottles, syringes, mail
• CPC Class Codes: A61L 2202/24 Medical instruments, e.g. endoscopes, catheters, sharps
• CPC Class Codes: B65B 55/00 Preserving, protecting or purifying packages or package contents in association with packaging by packaging under special atmospheric or gaseous conditions B65B31/00; devices for placing protecting sheets, plugs, or wads over contents B65B61/22
• CPC Class Codes: B65B 55/16 by irradiation

Abstract

Methods and systems for reduced temperature radiation sterilization of stents are disclosed.

Claims

1. A method of sterilizing a stent comprising:

cooling a stent to a sterilization temperature below ambient temperature; and

exposing the cooled stent to a dose of radiation.

2. The method of claim 1, wherein the dose of radiation is sufficient to sterilize the stent.

3. The method of claim 1, wherein the sterilization temperature less than 0°

C.

4. The method of claim 1, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

5. The method of claim 1, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

6. The method of claim 1, wherein the radiation is selected from the group consisting of e-beam, gamma ray, ultraviolet, infra-red, ion beam, x-ray, and laser.

7. The method of claim 1, wherein the exposing is repeated one or more times.

8. A method of sterilizing a stent comprising:

cooling a stent to a sterilization temperature below ambient temperature;

exposing the stent to a dose of radiation; and

cooling the stent during the exposure to maintain the temperature of the stent during exposure at less than a selected temperature.

9. The method of claim 8, wherein the stent is disposed in a radiation chamber during exposure.

10. The method of claim 9, wherein the stent is cooled by a cooling gas conveyed into the chamber.

11. The method of claim 9, wherein the stent is cooled by a cold medium disposed within the chamber selected from the group consisting of ice, dry ice, liquid nitrogen, or a freezable gel.

12. The method of claim 8, wherein the exposing and cooling is repeated one or more times.

13. The method of claim 8, wherein the dose of radiation is sufficient to sterilize the stent.

14. The method of claim 8, wherein the sterilization temperature less than 0°

C.

15. The method of claim 8, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

16. The method of claim 8, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

17. The method of claim 8, wherein the radiation is selected from the group consisting of e-beam, gamma ray, ultraviolet, infra-red, ion beam, x-ray, and laser.

18. A system for packaging a stent comprising:

a container capable of storing a stent;

a stent disposed within the container; and

a cold medium disposed within the container adjacent to the stent, the cold medium capable of reducing and maintaining the temperature of the stent below ambient temperature.

19. The system of claim 18, wherein the cold medium can reduce the temperature of the stent below 0°

C.

20. The system of claim 18, wherein the cold media is selected from the group consisting of ice, dry ice, and freezable gel.

21. The system of claim 18, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

22. The system of claim 18, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

23. A method for packaging a stent comprising:

disposing a stent in a container for storing the stent, wherein a cold medium is disposed within the container, the cold medium reducing and maintaining the temperature of the stent below ambient temperature; and

exposing the stent to a dose of radiation to sterilize the stent.

24. The method of claim 23, wherein the cold medium can reduce the temperature of the stent below 0°

C.

25. The method of claim 23, wherein the cold medium is selected from the group consisting of ice, dry ice, and freezable gel.

26. The method of claim 23, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

27. The method of claim 23, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

28. A method of sterilizing a stent comprising:

selectively conveying a cooling fluid at or adjacent to a stent to reduce the temperature of the stent to a sterilization temperature below an ambient temperature; and

directing a dose of radiation at the cooled stent.

29. The method of claim 28, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

30. The method of claim 28, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

31. The method of claim 28, wherein the cooling fluid is conveyed by a nozzle.

32. A method of sterilizing a stent comprising:

disposing a stent in a container;

disposing a cooling medium adjacent to the stent to reduce and/or maintain a temperature of the stent in the container at a sterilization temperature that is below ambient temperature; and

directing a dose of radiation at the container to sterilize the stent.

33. The method of claim 32, wherein the stent is positioned at a distal end of a catheter, all or a majority of the catheter being outside of the container.

34. The method of claim 32, wherein radiation exposure of the stent is less than the dose directed at the container, the container walls reducing the dose directed at the container.

35. The method of claim 32, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

36. The method of claim 32, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

37. A method of sterilizing a stent comprising:

cooling a stent to a sterilization temperature below an ambient temperature; and

directing a dose of radiation from a radiation source at the cooled stent, a radiation barrier between the stent and the radiation source selectively reducing the radiation exposure of the stent.

38. The method of claim 37, wherein the barrier comprises foam.

39. The method of claim 37, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

40. The method of claim 37, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

41. The method of claim 37, wherein the stent is positioned at a distal end of a catheter, all or a majority of the catheter being exposed to the dose radiation without reduction.

42. A system for sterilizing a stent comprising:

a hollow ring-shaped conduit including a plurality of holes for disposing a stent;

a cooling medium within the conduit for maintaining the temperature of a stent disposed through one of the holes within the conduit in a sterilization temperature range; and

a radiation source capable of exposing the conduit to a dose of radiation as the conduit is translated through the radiation source, the source being capable of exposing the stent to radiation..

43. The method of claim 42, wherein the cooling medium comprises a cooling gas circulating through the conduit.

44. The method of claim 42, wherein the cooling medium comprises an interior conduit having a cooling fluid within the interior conduit.

45. The method of claim 42, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

46. The method of claim 42, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

47. A method for sterilizing a stent comprising:

disposing a stent on or adjacent to a surface of a cooling member, wherein the cooling member maintains a temperature of the stent at a sterilization temperature below ambient temperature before, during, and/or after exposing the stent to radiation; and

directing a dose of radiation at the stent, the stent being positioned between the cooling slab and the radiation source.

48. The method of claim 47, wherein a barrier positioned between the radiation source and the stent distributes or reduces the radiation exposure to the stent.

49. The method of claim 47, wherein the cooling member comprises a slab with a cooling fluid circulating within the slab.

50. The method of claim 47, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

51. The method of claim 47, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

52. A system for sterilizing a stent comprising:

a cooling member capable of maintaining a temperature of a stent at a sterilization temperature below ambient temperature before, during, and/or after exposing the stent to radiation, wherein the stent is positioned on or adjacent to a surface of the cooling member; and

a radiation source for exposing the stent to radiation to sterilize the stent, the stent being positioned between the cooling member and the radiation source.

53. The system of claim 52, wherein a barrier is positioned between the radiation source and the stent to distribute or reduce the radiation exposure to the stent.

54. The system of claim 52, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

55. The system of claim 52, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

56. A method of sterilizing a stent comprising:

disposing a stent adjacent to a surface of a cooling member;

conveying a cooling fluid from the surface of the cooling member, wherein the cooling fluid facilitates maintaining a temperature of the stent at a sterilization temperature below ambient temperature before, during, and/or after exposing the stent to radiation; and

directing a dose of radiation at the stent, the stent being positioned between the cooling member and the radiation source.

57. The method of claim 56, wherein the cooling member comprises a cooling medium disposed in a cavity in the cooling member.

58. The method of claim 57, wherein the cooling fluid is conveyed into the cooling member is cooled through contact with the cooling medium.

59. The method of claim 56, wherein a barrier positioned between the radiation source and the stent increases the uniformity of distribution radiation or reduces the radiation exposure to the stent.

60. The method of claim 56, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

61. The method of claim 56, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

62. A system for sterilizing a stent comprising:

a cooling member including a cooling medium disposed in cavity of the cooling medium, the surface of the cooling member having a plurality of holes in communication with the cavity, the holes for conveying a cooling fluid from the surface of the cooling member, the cooling fluid facilitating maintaining a temperature of a stent disposed at or adjacent to the surface of the cooling member at a sterilization temperature below ambient temperature before, during, and/or after exposing the stent to radiation; and

a radiation source for exposing the stent to radiation, the stent being positioned between the cooling member and the radiation source.

63. The system of claim 62, wherein a barrier positioned between the radiation source and the stent distributes or reduces the radiation exposure to the stent.

64. The system of claim 62, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

65. The system of claim 62, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

66. A system for sterilizing a stent comprising:

a stent disposed in a storage container, the storage container being disposed within a cavity of a body of thermal insulating material;

a cold medium disposed adjacent to the storage container within the cavity to cool the stent; and

a radiation source for directing radiation at the stent to sterilize the stent.

67. The system of claim 66, wherein the cold medium is positioned so that cold medium is not between the directed radiation and the stent.

68. The system of claim 66, further comprising a second cold medium positioned in the cavity adjacent to the stent on a side opposite to the cold medium.

69. The system of claim 66, wherein the cold medium is selected from the group comprising ice, dry ice, and a freezable gel.

70. The system of claim 66, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

71. The system of claim 66, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

72. The system of claim 66, wherein the thermal insulating material comprises foam insulation.

73. A method of sterilizing a stent comprising:

disposing a storage container containing a stent within a cavity of a body a thermal insulating material, wherein a cold medium is disposed adjacent to the storage container within the cavity to cool the stent; and

directing radiation at the stent.

74. The method of claim 73, wherein the radiation is directed so that the radiation exposing the stent does not pass through the cold medium.

75. The method of claim 73, wherein the cold medium and the stent are positioned so that the cold medium is not between the directed radiation and the stent.

76. The method of claim 73, wherein the stent substrate comprises a biostable polymer, biodegradable polymer, or a combination thereof.

77. The method of claim 73, wherein the stent comprises a coating including a biostable polymer, biodegradable polymer, drug, or a combination thereof.

78. A system for sterilizing a stent comprising:

a stent disposed in a storage container, the container including a sealed storage region including the stent and a cooling region adjacent to the storage region, the cooling region including a cold medium for reducing and maintaining the temperature of the stent below an ambient temperature.

79. The system of claim 78, further comprising a radiation source adjacent the storage container for exposing the stent to radiation for sterilization of the stent.

80. The system of claim 78, wherein the cooling region comprises a thermoform pocket attached to the sealed storage region.

81. The system of claim 78, wherein the cooling region comprises a sleeve attached to the sealed storage region, a cold medium disposed within the sleeve.

82. The system of claim 78, wherein the cold medium is selected from the group consisting of ice, dry ice, and a freezable gel.

83. A method of sterilizing of a stent comprising:

directing radiation at a stent in a storage container, the container including a sealed storage region including the stent and a cooling region adjacent to the storage region, the cooling region including a cold medium for reducing and maintaining the temperature of the stent below an ambient temperature.

84. A system for sterilizating of a stent comprising:

a cooling container comprising a cooling region and a sleeve adjacent to the cooling region, the cooling region including a cold medium; and

a sealed stent storage container including a stent, the container disposed in the sleeve, the cold medium reduces and maintains the temperature of the stent below an ambient temperature.

85. The system of claim 84, further comprising a radiation source adjacent to the sleeve for exposing the stent to radiation for sterilization of the stent.

86. The system of claim 84, wherein the cooling region comprises a thermoform pocket attached to the sealed storage region.

87. The system of claim 84, wherein the cooling region comprises a cold medium, the cold medium is selected from the group consisting of ice, dry ice, and a freezable gel.