Fugitive plasticizer balloon surface treatment for enhanced stent securement

• US 20060142834A1
• Filed: 12/23/2004
• Published: 06/29/2006
• Est. Priority Date: 12/23/2004
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Chen, John J., Rizq, Raed, Nordin, Stanley
• Granted Patent: US 9,586,030 B2
• Time in Patent Office: Days
• US Class Current: 623/1.110
• CPC Class Codes: A61F 2/958 Inflatable balloons for placing stents or stent-grafts
• CPC Class Codes: A61F 2002/9583 Means for holding the stent on the balloon, e.g. using protrusions, adhesives or an outer sleeve
• CPC Class Codes: A61M 2025/1088 having special surface characteristics depending on material properties or added substances, e.g. for reducing friction
• CPC Class Codes: A61M 25/1027 Making of balloon catheters

Abstract

In an assembly of a balloon mounted on a catheter and a stent mounted over the deflated balloon, the balloon is provided with a fugitive plasticizer before the stent is crimped over the balloon. The fugitive plasticizer can soften the balloon surface so that molding of the balloon surface to conform to the crimped stent occurs. The fugitive plasticizer is removed before the assembly is used.

Claims

1. An assembly comprising a catheter, a deflated balloon mounted on the catheter and a stent mounted over the balloon, wherein

the balloon comprises polymer material having a fugitive plasticizer distributed therein.

2. An assembly as in claim 1 wherein the fugitive plasticizer is a compound that is a liquid at ambient temperature and pressure and has a boiling point at standard pressure of from about 95°

C. to about 200°

C.

3. An assembly as in claim 2 wherein the fugitive plasticizer is a compound or mixture of compounds that can solubilize the polymer only at elevated temperatures above about 120°

C.

4. An assembly as in claim 1 wherein the fugitive plasticizer is water.

5. An assembly as in claim 1 wherein the polymer material comprises a polymer that forms inter-chain hydrogen bonds and the fugitive plasticizer is water or a polar organic compound.

6. An assembly as in claim 1 wherein the polymer material comprises a polyamide, a polyurethane, a polyester, a block copolymer having at least one polyamide block, a block copolymer having at least one polyester block or a block copolymer having at least one polyurethane block.

7. An assembly as in claim 6 wherein the polymer material is a polyamide/polyether block copolymer.

8. An assembly as in claim 1 wherein the balloon has a multilayer structure and said polymer material having the fugitive plasticizer distributed therein is the material of an outer layer thereof.

9. An assembly as in claim 1 wherein the fugitive plasticizer is a member of the groups consisting of polyhydric alcohols;

mono- and di-alkyl glycol ethers;

acetate esters of glycol monoalkyl ethers;

isophorone;

benzyl alcohol;

3-methoxybutanol-1;

3-methoxybutanol-3;

ethylene carbonate;

propylene carbonate;

phenylglycol ethers;

2,2,4-trimethyl-1,3-pentanediol monoisobutyrate;

phenols;

dihydroxybenzenes;

water, and mixtures of two or more thereof.

10. An assembly comprising a catheter, a deflated balloon mounted on the catheter and a stent crimped over the balloon, the stent having a coating comprising a drug, wherein the stent has been crimped on the balloon while the balloon was in a softened state to produce a pillowing of the balloon material between openings in the stent, said pillowing having been produced without exposing the drug coating to a temperature in excess of 50°

C. or exposing the balloon material to a solvent therefor.

11. An assembly as in claim 10 wherein the drug coating has not been exposed to a temperature above ambient temperature.

12. An assembly as in claim 10 wherein the drug coating comprises paclitaxel.

13. A method of producing a balloon catheter suitable for use as a stent delivery device the method comprising:

treating at least the balloon portion of the balloon catheter with a fugitive plasticizer to soften the balloon material.

14. A method of producing a balloon catheter/stent assembly comprising:

crimping a stent over a balloon mounted on a catheter, the balloon catheter having been produced by the method of claim 13, and

subsequently substantially removing the fugitive plasticizer from the balloon.

15. A method as in claim 14 wherein the fugitive plasticizer is removed by volatilization without exceeding a temperature of 50°

C.

16. A method as in claim 15 wherein the fugitive plasticizer is water.

17. A method as in claim 14 wherein the stent is a drug coated stent.

18. The method of claim 17 wherein the drug coating comprises paclitaxel.

19. The method of claim 14 wherein the balloon is formed of polymer material comprising a polymer that forms inter-chain hydrogen bonds and the fugitive plasticizer is water or a polar organic compound.

20. The method of claim 14 wherein the balloon is formed of polymer material comprising a polyamide, a polyurethane, a block copolymer having at least one polyamide block or a block copolymer having at least one polyurethane block.

21. The method of claim 20 wherein the polymer material is a polyamide/polyether polyester.

22. The method of claim 13 wherein the treating step comprises immersing the balloon in a liquid bath of the fugitive plasticizer.

23. The method of claim 13 wherein the treating step comprises subjecting at least the balloon portion of the balloon catheter to vapors of the fugitive plasticizer.