Surface protection method for stents and balloon catheters for drug delivery

• US 6,419,692 B1
• Filed: 02/03/1999
• Issued: 07/16/2002
• Est. Priority Date: 02/03/1999
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Yang, Duchuan, Wang, Lixiao, Stanslaski, Joel
• Primary Examiner(s): Willse, David H.
• Assistant Examiner(s): GHERBI, SUZETTE JAIME J
• Application Number:
  US09/243,580
• Time in Patent Office: 1,259 Days
• Field of Search: 623/1.44, 623/1.45, 623/1.46, 623/1.47, 623/1.48, 623/1.42, 427/2.1, 427/2.2, 427/2.3, 427/2.31
• US Class Current: 623/1.15
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61F 2/91 made from perforated sheet material or tubes, e.g. perforated by laser cuts or etched holes
• CPC Class Codes: A61F 2/915 with bands having a meander structure, adjacent bands being connected to each other
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/91541 Adjacent bands are arranged out of phase
• CPC Class Codes: A61F 2002/91558 connected peak to peak
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61L 2300/416 Anti-neoplastic or anti-proliferative or anti-restenosis or anti-angiogenic agents, e.g. paclitaxel, sirolimus
• CPC Class Codes: A61L 2300/608 having two or more layers
• CPC Class Codes: A61L 2420/08 Coatings comprising two or more layers
• CPC Class Codes: A61L 29/085 Macromolecular materials
• CPC Class Codes: A61L 29/16 Biologically active materials, e.g. therapeutic substances A61L29/048 takes precedence
• 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

Abstract

A medical device, such as a stent or balloon of a balloon catheter which includes a body portion which has an exterior surface which contacts, at least in part, a vessel wall during treatment. The body portion is expandable from a first position, wherein the body portion is sized for insertion into the vessel lumen, to a second position, wherein at least a portion of the exterior surface is in contact with the lumen wall. The medical device includes a first coating disposed over at least a portion of the exterior surface of the body portion with the first coating including a drug or therapeutic substance which is intended for controlled release from the surface. The medical device further includes a second coating overlying at least a substantial portion of the first coating. The second coating includes a material that is generally impervious to elution of the drug or therapeutic substance therethrough when the body portion is in a first position when inserted into the vessel lumen. The material of the second coating is relatively inelastic so that the second coating fractures during expansion of the body portion to the second position to allow elution of therapeutic substance through a multiplicity of fissures formed through the second coating.

Claims

1. A medical device for treating a lumen wall comprising:

a body portion having an exterior surface defined thereon, said body portion being expandable from a first position, wherein said body portion is sized for insertion into said lumen, to a second position wherein at least a portion of said exterior surface is in contact with said lumen wall;

a first coating disposed over at least a portion of said exterior surface of said body portion, said first coating comprising at least in part a therapeutic substance; and

,

a second coating overlying at least a substantial portion of said first coating, said second coating comprising a material that is impervious to elution of said therapeutic substance therethrough when said body portion is in said first position when inserted in said lumen, while being relatively inelastic so that said second coating fractures during expansion of said body portion to said second position to allow elution of said therapeutic substance through fissures formed therethrough.

2. The medical device of claim 1, wherein said device is an expandable stent.

3. The medical device of claim 1, wherein said therapeutic substance releases from said exterior surface in response to fluid contact with said first coating.

4. The medical device of claim 1, wherein said therapeutic substance is selected from the group consisting of:

heparin, antibiotics, radiopaque agents, anti-thrombogenic agents, anti-proliferative agents, anti-angiogenic agents and combinations thereof.

5. The medical device of claim 4, wherein said anti-proliferative and anti-angiogenic agents are selected from the group consisting of:

taxol, taxol derivatives, colchicine, vinblastine, and epothilone.

6. The medical device of claim 3, wherein said fluid contact includes blood within said lumen.

7. The medical device of claim 1, wherein said first coating further comprises a polymeric carrier having said therapeutic substance dispersed therethrough.

8. The medical device of claim 7, wherein said polymeric carrier is biodegradable.

9. The medical device of claim 8, wherein said polymeric carrier is selected from the group consisting of:

polylactic acid, polyglycolic acid, polyethylene oxide, polycaprolactone, polydioxanones, polyanhydrides, polyphosphazenes, poly(orthoesters) and mixtures or copolymers thereof.

10. The medical device of claim 1, wherein said second coating is a polymeric material selected from the group consisting of:

polylactic acid, polyglycolic acid, polyanhydrides, polyphosphazenes, poly(orthoesters) and mixture and copolymers thereof.

11. The medical device of claim 10, wherein said second coating has a thickness of about 0.01 μ

m to about 5.0 μ

m.

29. The medical device of claim 1, wherein said device is a balloon catheter.

12. An intravascular stent adapted for treating a vessel wall comprising:

a generally tubular structure having an exterior surface defined by a plurality of interconnected struts having interstitial spaces therebetween, said generally tubular structure expandable from a first position, wherein said stent is sized for intravascular insertion, to a second position, wherein at least a portion of said exterior surface contacts said vessel wall, said expanding of said generally tubular structure accommodated by flexing and bending of said interconnected struts;

a first coating disposed over at least a portion of said exterior surface of said generally tubular structure, said first coating comprising at least in part a therapeutic substance; and

,

a second coating overlying at least a substantial portion of said first coating, said second coating comprising a material that is impervious to elution of said therapeutic substance therethrough when said body portion is in said first position within said intravascular lumen, while being relatively inelastic so that said second coating fractures in response to flexing and bending of said struts during expansion to said second position to allow elution of said therapeutic substance through fissures formed therethrough.

13. The stent of claim 12, wherein said therapeutic substance releases from said exterior surface in response to fluid contact absent said second coating.

14. The stent of claim 12, wherein said therapeutic substance is selected from the group consisting of:

heparin, antibiotics, radiopaque agents, anti-thrombogenic agents, anti-proliferative agents, anti-angiogenic agents and combinations thereof.

15. The stent of claim 14, wherein said anti-proliferative and anti-angiogenic agents are selected from the group consisting of:

taxol, taxol derivatives, colchicine, vinblastine and epothilone.

16. The stent of claim 13, wherein said fluid contact includes blood within said lumen.

17. The stent of claim 12, wherein said first coating further comprises a polymeric carrier having said therapeutic substance dispersed therethrough.

18. The stent of claim 17, wherein said polymeric carrier is biodegradable.

19. The stent of claim 18, wherein said polymeric carrier is selected from the group consisting of:

polylactic acid, polyglycolic acid, polyethylene oxide, polycaprolactone, polydioxanone, polyanhydrides, polyphosphaenes, poly(orthoesters) and mixtures or copolymers thereof.

20. The stent of claim 12, wherein said therapeutic substance is elutable in contact with water containing fluids absent said second coating.

21. In an intravascular medical device having a body portion with an exterior surface defined thereon, at least a portion of said body portion which is expandable from a folded or unexpanded first position, which is adapted for insertion into a vascular lumen to an expanded second position, which is adapted for treatment of the vascular lumen wall by contact with at least a portion of said exterior surface, the improvement comprising:

a first coating disposed over at least a portion of said exterior surface of said body portion, said first coating comprising at least in part a therapeutic substance; and

,

a second coating overlying at least a substantial portion of said first coating, said second coating comprising a material that is impervious to elution of said therapeutic substance and that is relatively inelastic so that said second coating fractures during expansion of said body portion to said second position to allow elution of said therapeutic substance through fissures formed therethrough.

22. The intravascular medical device of claim 21, wherein said therapeutic substance releases from said exterior surface in response to fluid contact with said first coating.

23. The intravascular medical device of claim 21, wherein said therapeutic substance is selected from the group consisting of:

heparin, antibiotics, radiopaque agents, anti-thrombogenic agents, anti-proliferative agents, anti-angiogenic agents and combinations thereof.

24. The intravascular medical device of claim 23, wherein said anti-proliferative and anti-angiogenic agents are selected from the group consisting of:

taxol, taxol derivatives, colchicine, vinblastine and epothilones.

25. The intravascular medical device of claim 21, wherein said first coating further comprises a polymeric carrier having said therapeutic substance dispersed therethrough.

26. The intravascular medical device of claim 25, wherein said polymeric carrier is biodegradable.

27. The intravascular medical device of claim 26, wherein said polymeric carrier is selected from the group consisting of:

polylactic acid, polyglycolic acid, polyethylene oxide, polycaprolactone, polydioxanone, polyanhydrides, polyphosphazenes, poly(orthoesters) and mixtures or copolymers thereof.

28. The intravascular medical device of claim 21, wherein said therapeutic substance is elutable in contact with water containing fluids absent said second coating.