Methods for forming polymeric coatings on stents

• US 7,682,648 B1
• Filed: 11/03/2003
• Issued: 03/23/2010
• Est. Priority Date: 05/31/2000
• Status: Expired due to Fees

• Current Assignee: Advanced Cardiovascular Systems Incorporated
• Original Assignee: Advanced Cardiovascular Systems Incorporated
• Inventors: Sanders Millare, Deborra, Hossainy, Syed F. A., Ding, Ni
• Primary Examiner(s): Meeks; Timothy H
• Assistant Examiner(s): Sellman; Cachet I
• Application Number:
  US10/700,710
• Time in Patent Office: 2,332 Days
• Field of Search: 427/2.1, 427/2.24, 427/2.25, 427/2.28, 623/1.1, 623/1.15, 623/1.2, 623/1.42, 623/1.44, 623/1.46
• US Class Current: 427/2.24
• CPC Class Codes: A61L 31/10 Macromolecular materials
• CPC Class Codes: C08F 290/061 Polyesters; Polycarbonates
• CPC Class Codes: C08F 290/062 Polyethers
• CPC Class Codes: C08K 5/053 Polyhydroxylic alcohols
• CPC Class Codes: C08K 5/103 with polyalcohols
• CPC Class Codes: C08K 5/1545 Six-membered rings
• CPC Class Codes: C08L 2205/05 containing polymer components which can react with one another
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 33/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 33/06 of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
• CPC Class Codes: C09D 133/00 Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
• CPC Class Codes: C09D 133/06 of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
• CPC Class Codes: C09D 133/10 Homopolymers or copolymers of methacrylic acid esters
• CPC Class Codes: C09D 133/12 Homopolymers or copolymers of methyl methacrylate
• CPC Class Codes: C09D 167/07 having terminal carbon-to-carbon unsaturated bonds
• CPC Class Codes: C09D 171/02 Polyalkylene oxides

Abstract

A method is provided for forming a polymeric coating on a stent. The method can comprise applying a prepolymer or a combination of prepolymers to the stent and initiating polymerization to form a polymeric coating on the stent. The coating material can optionally contain a biologically active agent or combination of agents.

Claims

1. A method of forming a polymeric coating on a stent, comprising:

(a) spraying a radially expandable stent with a coating fluid, the coating fluid comprising a prepolymer, a bioactive agent mixed with the prepolymer, and an additive for increasing the viscosity of the fluid; and

(b) causing the prepolymer to react to form a polymeric coating on the stent;

wherein the prepolymer comprises a hydrophobic macromer comprising structural units of a polymer, wherein the bioactive agent is contained in the polymeric coating, and wherein the polymer forming the coating is a thermoplastic linear polymer comprising a multiple repetition of units derived from the macromer or combination of macromers in linear sequence and is free from cross-linked fragments.

2. The method of claim 1, wherein the coating fluid further comprises a solvent or a combination of solvents.

3. The method of claim 1, wherein the prepolymer is in a fluid phase at room temperature.

4. The method of claim 1, wherein the prepolymer comprises acrylate, vinyl or allyl compounds.

5. The method of claim 1, wherein the bioactive agent is for the treatment of restenosis.

6. The method of claim 1, wherein the act of causing the prepolymer to react comprises initiation by step-function reaction, radical chain reaction, or ionic polymerization processes.

7. The method of claim 1, additionally comprising applying to the stent a second fluid comprising at least one other prepolymer, different than the prepolymer of the coating fluid, wherein the prepolymers of the coating fluid and second fluid are capable of reacting to form a polymeric coating.

8. The method of claim 1, additionally comprising applying to the stent a monomer for creating functional groups on the surface of the polymeric coating.

9. The method of claim 1, further comprising combining an initiator of polymerization with the prepolymer.

10. The method of claim 9, wherein the initiator is selected from the group consisting of a thermal initiator, a photo initiator, a redox initiator, an initiator for radiation initiation and an initiator for electroinitiation.

11. The method of claim 1, wherein the additive is selected from the group consisting of glucose, caster oil, cotton seed oil, glycerol, poly(vinyl pyrrolidone), and poly(n-butylmethacrylate), and any combination thereof.

12. A method of forming a polymeric coating for a stent, comprising:

(a) applying polycaprolactone diacrylate to the stent; and

(b) polymerizing the polycaprolactone diacrylate to form a polymeric coating for the stent;

wherein the polymeric coating comprises a thermoplastic linear polymer comprising a multiple repetition of units derived from the polycaprolactone diacrylate in linear sequence and is free from cross-linked fragments.

13. A method of forming a polymeric coating on a stent, comprising:

(a) spraying a radially expandable stent with a coating fluid, the coating fluid comprising a prepolymer and a bioactive agent mixed with the prepolymer;

(b) causing the prepolymer to react to form a polymer; and

(c) adding a non-solvent to precipitate the polymer formed by the reaction of the prepolymer such that a polymeric coating is formed on the stent;

wherein the prepolymer comprises a hydrophobic macromer comprising structural units of the polymer, wherein the bioactive agent is contained in the polymeric coating, and wherein the polymer forming the coating is a thermoplastic linear polymer comprising a multiple repetition of units derived from the macromer or combination of macromers in linear sequence and is free from cross-linked fragments.

14. A method of forming a polymeric coating on a stent, comprising:

(a) spraying a radially expandable stent with a coating fluid, the coating fluid comprising a prepolymer, a bioactive agent mixed with the prepolymer, and a wetting fluid; and

(b) causing the prepolymer to react to form a polymeric coating on the stent;

wherein the prepolymer comprises a hydrophobic macromer comprising structural units of a polymer, wherein the bioactive agent is contained in the polymeric coating, and wherein the polymer forming the coating is a thermoplastic linear polymer comprising a multiple repetition of units derived from the macromer or combination of macromers in linear sequence and is free from cross-linked fragments.

15. The method of claim 14, wherein the wetting fluid is selected from the group consisting of tetrahydrofuran, dimethylformamide, 1-butanol, n-butyl acetate, dimethylacetamide (DMAC), and any combination thereof.

16. A method of forming a polymeric coating for a stent, comprising:

(a) applying n-butyl methacrylate and an initiator to the stent; and

(b) polymerizing the n-butyl methacrylate to form a poly(n-butylmethacrylate) polymeric coating for the stent;

wherein the polymeric coating comprises a thermoplastic linear polymer.