Method for fabricating a coating for a medical device

• US 6,926,919 B1
• Filed: 02/26/2003
• Issued: 08/09/2005
• Est. Priority Date: 02/26/2003
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Original Assignee: Advanced Cardiovascular Systems Incorporated (Abbott Laboratories)
• Inventors: Tang, Yiwen, Pacetti, Stephen D., Hossainy, Syed F. A., Tung, Andrew C.
• Primary Examiner(s): Chen, Vivian
• Application Number:
  US10/375,620
• Time in Patent Office: 895 Days
• Field of Search: 428/480, 428/500, 428/34.1, 427/2.1, 427/2.24, 427/2.25, 427/2.28, 427/2.3, 427/2.31, 427/331, 427/372.2, 427/377, 427/384, 427/398.1
• US Class Current: 427/2.25
• CPC Class Codes: A61F 2/0077 Special surfaces of prostheses, e.g. for improving ingrowth A61F2/30767 takes precedence
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer

Abstract

Methods for fabricating coatings for implantable medical devices are disclosed. The coatings include blends of hydrophilic and hydrophobic polymers. The methods provide for treatment of the coatings to cause enrichment a region close to the outer surface of the coating with the hydrophilic polymers.

Claims

1. A method for fabricating a coating for an implantable medical device, comprising:

(a) forming a coating on the device, the coating including a blend of a hydrophobic polymer and a hydrophilic polymer; and

(b) treating the coating with a stimulus for enriching a region close to or at the outer surface of the coating with the hydrophilic polymer, wherein the hydrophilic polymer has a Hildebrand solubility parameter higher than about 11 (cal/cm³)^1/2.

6. The method of claim 1, 2, 3 or 4, wherein the implantable medical device is a stent.

7. The method of claim 1, 2, 3 or 4, wherein the hydrophilic polymer is selected from a group consisting of poly(ethylene glycol), polyvinyl pyrrolidone) and blends thereof.

8. The method of claim 1, 2, 3 or 4, wherein a mass ratio between the hydrophilic polymer and the hydrophobic polymer in the blend is between about 1:

100 and about 1;

9.

9. The method of claim 1, 2, 3 or 4, wherein the stimulus comprises subjecting the device to a humid environment at a selected temperature for a period of time.

10. The method of claim 9, wherein the temperature is between about 40°

C. and about 80°

C. and the humidity is between about 90% and about 100%.

11. The method of claim 9, wherein the period of time is between about 12 hours and about 28 hours.

12. The method of claim 1, 2, 3 or 4, wherein the treating of the coating comprises subjecting the device to a temperature between about 4°

C. and about −

20°

C. for a period of time.

13. The method of claim 12, wherein the period of time is between about 30 minutes and about 2 hours.

14. The method of claim 12, further comprising exposing the device to ambient atmosphere subsequent to the exposing the device to the temperature between about 4°

C. and about <

20°

C.

15. The method of claim 12, further comprising subjecting the device to a humid environment at a selected temperature.

16. The method of claim 15, wherein the temperature is between about 40°

C. and about 80°

C. and the humidity is between about 90% and about 100%.

2. A method for fabricating a coating for an implantable medical device, comprising:

(a) forming a coating on the device, the coating including a blend of a hydrophobic polymer and a hydrophilic polymer; and

(b) treating the coating with a stimulus for enriching a region close to or at the outer surface of the coating with the hydrophilic polymer, wherein the hydrophobic polymer is selected from a group consisting of poly(ethylene-co-vinyl alcohol), poly(butyl methacrylate), poly(ethyl methacrylate), poly(ethyl methacrylate-co-butyl methacrylate), poly(vinylidene fluoride), poly(vinylidene fluoride-co-hexafluoro propene), and blends thereof.

3. A method for fabricating a coating for an implantable medical device, comprising:

(a) forming a coating on the device, the coating including a blend of a hydrophobic polymer and a hydrophilic polymer; and

(b) treating the coating with a stimulus for enriching a region close to or at the outer surface of the coating with the hydrophilic polymer, wherein the stimulus comprises chilling the device followed by exposing the device to ambient atmosphere or a humid environment.

4. A method for fabricating a coating for an implantable medical device, comprising:

(a) forming a coating on the device, the coating including a blend of a hydrophobic polymer and a hydrophilic polymer; and

(b) treating the coating with a stimulus for enriching a region close to or at the outer surface of the coating with the hydrophilic polymer, wherein the stimulus comprises contacting the coating surface with a film of a hydrogel.

5. The method of claim 4, wherein the hydrogel is made of poly(vinyl alcohol).

17. A method for fabricating a coating for a scent, comprising:

(a) forming a coating layer on the stent, the coating layer including a hydrophobic component and a hydrophilic component; and

(b) promoting the migration of the hydrophilic component towards the surface of the coating layer of the scent, wherein the hydrophilic component has a solubility parameter higher than about 11 (cal/cm³)^1/2.

18. The method of claim 17, wherein the hydrophobic and hydrophilic components are blended.

19. The method of claim 17, wherein the hydrophobic and hydrophilic components are chemically bonded.

20. The method of claim 17, wherein the hydrophobic and hydrophilic components are an interpenetrating polymer network (IPN).

21. A method for fabricating a coating for a stent, comprising:

(a) forming a coating layer on the stent, the coating layer including a hydrophobic component and a hydrophilic component; and

(b) promoting the migration of the hydrophilic component towards the surface of the coating layer, wherein the hydrophobic component is selected from a group consisting of poly(ethylene-co-vinyl alcohol), poly(butyl methacrylate), poly(ethyl methacrylate), poly(ethyl methacrylate-co-butyl methacrylate), poly(vinylidene fluoride), poly(vinylidene fluoride-co-hexafluoro propene), and blends thereof.

22. The method of claim 21, wherein the hydrophilic component comprises poly(ethylene glycol).

23. The method of claim 21, wherein the hydrophilic component comprises poly(vinyl pyrrolidone).

24. A method for fabricating a coating for a stent, comprising:

(a) forming a coating layer on the stent, the coating layer including a hydrophobic component and a hydrophilic component; and

(b) promoting the migration of the hydrophilic component towards the surface of the coating layer wherein the promotion comprises chilling the stent followed by exposing the stent to ambient atmosphere or a humid environment.

25. A method for fabricating a coating for a stent, comprising:

(a) forming a coating layer on the stent, the coating layer including a hydrophobic component and a hydrophilic component; and

(b) promoting the migration of the hydrophilic component towards the surface of the coating layer wherein the promotion comprises contacting the coating surface with a hydrogel.

26. The method of claim 25, wherein the hydrogel includes poly(vinyl alcohol).