Laminated drug-polymer coated stent with dipped and cured layers

• US 7,744,645 B2
• Filed: 09/29/2003
• Issued: 06/29/2010
• Est. Priority Date: 09/29/2003
• Status: Expired due to Fees

• Current Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Original Assignee: Medtronic Vascular, Inc. (Medtronic Plc)
• Inventors: Dolan, Finbar, Thornton, Ronan
• Primary Examiner(s): McDermott; Corrine M
• Assistant Examiner(s): Prone; Christopher D
• Application Number:
  US10/674,296
• Publication Number:
  US 20050070997A1
• Time in Patent Office: 2,465 Days
• Field of Search: 623/1.39, 623/1.42, 623/1.44, 623/1.46
• US Class Current: 623/1.46
• CPC Class Codes: A61L 2300/608 having two or more layers
• CPC Class Codes: A61L 2420/02 Methods for coating medical devices
• CPC Class Codes: A61L 2420/08 Coatings comprising 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: C08L 33/02 Homopolymers or copolymers of acids; Metal or ammonium salts thereof
• CPC Class Codes: C08L 39/06 Homopolymers or copolymers of N-vinyl-pyrrolidones
• CPC Class Codes: C08L 83/04 Polysiloxanes
• CPC Class Codes: Y10T 428/31663 As siloxane, silicone or silane

Abstract

The present invention provides a method of applying a drug-polymer coating on a stent. A stent framework is dipped into a first polymeric solution including a first polymer, a first therapeutic agent, and a first solvent. The polymeric solution is dried and the first polymer is cured to form a thin drug-polymer layer on the stent framework. The steps of dipping the stent framework into the first polymeric solution, drying the first polymeric solution, and curing the first polymer are repeated until a target drug-polymer coating thickness is disposed on the stent framework. A drug-polymer coated stent including a stent framework and a laminated drug-polymer coated stent, a system for treating a vascular condition, and a method of treating a vascular condition are also disclosed.

Claims

1. A drug-polymer coated stent, comprising:

a stent framework;

a laminated drug-polymer coating disposed on the stent framework, the laminated drug-polymer coating including a plurality of thin drug-polymer layers, wherein the thin drug-polymer layers include a first therapeutic agent and a cured first polymer, and

at least one thin barrier layer positioned between a first thin drug-polymer layer and a second thin drug-polymer layer, wherein the at least one thin barrier layer includes a cured second polymer, wherein the cured second polymer excludes drug interaction between the first thin drug-polymer layer and the second thin drug-polymer layer adjacent the at least one barrier layer.

2. The stent of claim 1 wherein the stent framework comprises one of a metallic base or a polymeric base.

3. The stent of claim 1 wherein the stent framework comprises a material selected from the group consisting of stainless steel, nitinol, tantalum, MP35N alloy, platinum, titanium, a chromium-based alloy, a suitable biocompatible alloy, a suitable biocompatible material, a biocompatible polymer, and a combination thereof.

4. The stent of claim 1 wherein the first therapeutic agent is selected from the group consisting of rapamycin, a rapamycin derivative, a rapamycin analogue, camptothecin, dexamethasone, 5-fluorouracil, a bioactive agent, a pharmaceutical drug, a therapeutic substance, and a combination thereof.

5. The stent of claim 1, wherein a concentration of the first therapeutic agent is modulated to provide a predetermined drug-release profile.

6. The stent of claim 1 wherein the at least one thin barrier layer comprises a diffusion barrier.

7. The stent of claim 1 wherein the cured second polymer comprises a silicone polymer.

8. The stent of claim 1 wherein the cured second polymer comprises an amphiphilic copolymer from acrylic acid and vinyl pyrollidone.

9. The stent of claim 1 further comprising a primer coat disposed directly on an outer surface of the stent framework.

10. A system for treating a vascular condition, comprising:

a catheter; and

a coated stent coupled to the catheter, the coated stent including a stent framework and a laminated drug-polymer coating disposed on the stent framework, the laminated drug-polymer coating including a plurality of thin drug-polymer layers and at least one thin barrier layer positioned between a first thin drug-polymer layer and a second thin drug-polymer layer ,

wherein the thin drug-polymer layers include a first therapeutic agent and a cured first polymer and wherein the at least one thin barrier layer includes a cured second polymer, wherein the cured second polymer excludes drug interaction between the first thin drug-polymer layer and the second thin drug-polymer layer adjacent the at least one barrier layer.

11. The system of claim 10 wherein the catheter includes a balloon to expand the stent.

12. The system of claim 10, wherein the catheter includes a sheath that retracts to allow expansion of the stent.

13. The system of claim 10 wherein the stent framework comprises one of a metallic base or a polymeric base.

14. The system of claim 10 wherein the stent framework comprises a material selected from the group consisting of stainless steel, nitinol, tantalum, MP35N alloy, platinum, titanium, a chromium-based alloy, a suitable biocompatible alloy, a suitable biocompatible material, a biocompatible polymer, and a combination thereof.

15. The system of claim 10 wherein the first therapeutic agent is selected from the group consisting of rapamycin, a rapamycin derivative, a rapamycin analogue, camptothecin, dexamethasone, 5-fluorouracil, a bioactive agent, a pharmaceutical drug, a therapeutic substance, and a combination thereof.

16. The system of claim 10 wherein a concentration of the first therapeutic agent is modulated to provide a predetermined drug-release profile.

17. The system of claim 10 wherein the at least one thin barrier layer comprises a diffusion barrier.

18. The system of claim 10 wherein the cured second polymer comprises a silicone polymer.

19. The system of claim 10 wherein the cured second polymer comprises an amphiphilic copolymer from acrylic acid and vinyl pyrollidone.

20. A method of treating a vascular condition, comprising:

inserting a drug-polymer coated stent within a vessel of a body, the drug-polymer coated stent including a laminated drug-polymer coating having a plurality of thin drug-polymer layers and at least one thin barrier layer positioned between a first thin drug-polymer layer and a second thin drug-polymer layer one, wherein the thin drug-polymer layers include a first therapeutic agent and a cured first polymer and wherein the at least one thin barrier layer includes a cured second polymer, wherein the cured second polymer excludes drug interaction between the first thin drug-polymer layer and the second thin drug-polymer layer adjacent the at least one barrier layer; and

eluting at least one therapeutic agent from the laminated drug-polymer coating into the body,

wherein the first polymer is cured with one of thermal activation, electrical activation, or ionizing irradiation.

21. The method of claim 20 wherein the thin barrier layers control an elution rate of at least one therapeutic agent.

22. The method of claim 20 further comprising:

selecting the cured first polymer and the cured second polymer based on a predetermined elution rate of at least one therapeutic agent.

23. The method of claim 20 wherein the at least one thin barrier layer comprises a diffusion barrier.