Polymer compositions for intraluminal stent

• US 20030149470A1
• Filed: 12/26/2002
• Published: 08/07/2003
• Est. Priority Date: 01/12/1999
• Status: Active Grant

• Current Assignee: Quanam Medical Corp (Boston Scientific Corporation)
• Original Assignee: Quanam Medical Corp (Boston Scientific Corporation)
• Inventors: Pomerantseva, Irina D., Froix, Michael, Eury, Robert, Alvarado, Angelica
• Granted Patent: US 6,653,426 B2
• Time in Patent Office: Days
• US Class Current: 623/1.13
• CPC Class Codes: A61K 31/337 having four-membered rings, e.g. taxol
• CPC Class Codes: A61K 9/0024 Solid, semi-solid or solidifying implants, which are implanted or injected in body tissue compositions for intravenous administration, normal injectable solutions or dispersions for, e.g. subcutaneous administration A61K9/0019; brain implants A61K9/0085; (coated) prostheses, catheters or stents A61L
• CPC Class Codes: A61K 9/127 Liposomes
• CPC Class Codes: A61L 2300/00 Biologically active materials used in bandages, wound dressings, absorbent pads or medical devices
• 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 31/041 Mixtures of macromolecular compounds
• CPC Class Codes: A61L 31/048 obtained by reactions only involving carbon-to-carbon unsaturated bonds A61L31/041 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
• CPC Class Codes: B82Y 5/00 Nanobiotechnology or nanomedicine, e.g. protein engineering or drug delivery
• CPC Class Codes: C08F 220/06 Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
• CPC Class Codes: C08F 220/14 Methyl esters , e.g. methyl (meth)acrylate
• CPC Class Codes: C08F 220/1804 C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate
• CPC Class Codes: C08F 220/22 Esters containing halogen
• CPC Class Codes: C08F 220/286 and containing polyethylene oxide in the alcohol moiety, e.g. methoxy polyethylene glycol (meth)acrylate
• CPC Class Codes: C08F 222/102 of dialcohols, e.g. ethylene glycol di(meth)acrylate or 1,4-butanediol dimethacrylate
• CPC Class Codes: C08L 33/04 Homopolymers or copolymers of esters C08L43/04 takes precedence

Abstract

A polymer composition for use in forming a stent is described. The composition includes a monomer of an aliphatic ester of acrylic acid which has a glass transition temperature less than 25° C. and a second monomer that copolymerizes with the first monomer and which has a glass transition temperature greater than 25° C. The components in the composition are mixed in amounts suitable to give a copolymer having a glass transition temperature less than 25° C., or in case of block copolymers, having at least one glass transition temperature less than 25° C. A stent including polymer members formed from the described composition is also disclosed.

Claims

1. A composition for use in forming a polymeric stent for insertion into a vessel, comprising

between 10-98% of a first monomer composed of an aliphatic ester C1-C50 of acrylic acid which when homopolymerized has a glass transition temperature lower than about 25°

C.; and

a second monomer having sites of unsaturation and capable of copolymerization with the first monomer, the second monomer when homopolymerized having a glass transition temperature greater than 25°

C.,

said monomers when polymerized in the presence of a crosslinker forming a polymer having a glass transition temperature of less than about 25°

C.

2. The composition of claim 1, wherein the first monomer is an aliphatic ester of acrylic acid.

3. The composition of claim 1, wherein the first monomer is fluorinated.

4. The composition of claim 1, wherein the first monomer is selected from butyl acrylate and pentafluoropropylacrylate.

5. The composition of claim 1, wherein said second monomer is an ester of methacrylic acid or an ester of acrylic acid.

6. The composition of claim 1, wherein the second monomer is selected from the group consisting of methylmethacrylate, isobornyl methacrylate, isobutyl methacrylate, perfluoroacetylmethacrylate, tertiary butylmethacrylate, phenylethylmethacrylate, styrene, hydroxyethyl methacrylate, glycerol methacrylate, n-vinyl pyrrolidone and heptadecylfluorodecyl-methacrylate.

7. The composition of claim 1, which further includes a third monomer of a methacrylic acid ester of polyethyleneoxide, where the ester side chain has a molecular weight of between 200-10,000 Daltons.

8. The composition of claim 7, wherein the third monomer is selected from the group consisting of polyethyleneglycol dimethacrylate, polyethyleneglycol methacrylate and polyethyleneglycol acrylate.

9. The composition of claim 7, wherein the first monomer is butyl acrylate, the second monomer is methylmethacrylate and the third monomer is polyethylene glycol methacrylate.

10. The composition of claim 1, wherein the first monomer is pentafluoropropylacrylate and the second monomer is heptadecylfluorodecyl methacrylate.

11. The composition of claim 7, wherein the first monomer is pentafluoropropylacrylate and the second monomer is methylmethacrylate and the third monomer is polyethylene glycol methacrylate.

12. A stent composed of the composition of claim 1, said stent including a therapeutic agent.

13. A composition for use in forming a polymeric stent for insertion into a vessel, comprising

(a) greater than about 40 weight percent of butyl acrylate monomer;

(b) between 3-30 weight percent of methylmethacrylate monomer;

(c) between 2-40 weight percent of polyethylene glycol methacrylate monomer or polyethyleneglycol monomethylether methacrylate;

said composition when polymerized forming a polymer having a glass transition temperature of less than 25°

C.

14. The composition of claim 13, which further includes one or more of the following components:

(a) between 0.1-20 weight percent of an organic solvent;

(b) a monomer effective to impart a charge to the polymer;

(c) between 0.025-0.1 weight percent of a crosslinker; and

(d) between 0.1-1 weight percent of a photoinitiator,

15. The composition of claim 14, wherein the solvent is dimethylformamide in an amount between 1-15 weight percent.

16. The composition of claim 14, wherein the monomer at physiologic pH is effective to impart a positive charge.

17. The composition of claim 16, wherein the monomer is dimethylaminoethyl methacrylate.

18. The composition of claim 14, wherein the monomer at physiologic pH is effective to impart a negative charge.

19. The composition of claim 18, wherein the monomer is methacrylic acid or acrylic acid.

20. The composition of claim 13, wherein the crosslinker is selected from the group consisting of ethoxylated trimethylolpropane triacrylate and hexanediol dimethacrylate.

21. A composition for use in forming a polymeric stent for insertion into a vessel, comprising

(a) greater than about 40 weight percent of pentafluoropropyl acrylate monomer;

(b) between 3-30 weight percent of (heptadecyl fluorodecyl methacrylate) monomer;

said composition when polymerized forming a polymer having a glass transition temperature of less than 25°

C.

22. A composition for use in forming a polymeric stent for insertion into a vessel, comprising

(a) greater than about 40 weight percent of pentafluoropropyl acrylate monomer;

(b) between 3-30 weight percent of polyethylene glycol methacrylate monomer or polyethyleneglycol monomethylether methacrylate monomer;

(c) between 2-40 weight percent of methylmethacrylate monomer;

said composition when polymerized forming a polymer having a glass transition temperature of less than 25°

C.

23. A stent for insertion into a lumen, comprising;

a radially expandable, support stent having a selected axial length and an outer surface, said stent having rigid regions and flexible regions along its length; and

one or more polymer members coaxially disposed about the outer surface of the support stent, said polymer members positioned over the rigid regions of the support stent, with the flexible regions exposed, and said polymer members being radially expandable with the support stent.

24. The stent of claim 23, wherein said polymer members are composed of (i) between 10-98% of a first monomer composed of an aliphatic ester C1-C50 of acrylic acid which when homopolymerized has a glass transition temperature lower than about 25°

C.; and

(ii) a second monomer having sites of unsaturation and capable of free radical polymerization, the second monomer when homopolymerized having a glass transition temperature greater than 25°

C., said monomers when polymerized in the presence of a crosslinker forming a polymer having a glass transition temperature of less than about 25°

C.

25. The stent of claim 24, wherein the first monomer is an aliphatic ester of methacrylic acid or an aliphatic ester of acrylic acid.

26. The stent of claim 24, wherein the first monomer is fluorinated.

27. The stent of claim 24, wherein the first monomer is selected from butyl acrylate and pentafluoropropylacrylate.

28. The stent of claim 24, wherein said second monomer is selected from the group consisting of an ester of methacrylic acid, polyethylene glycol methacrylate monomer and polyethyleneglycol monomethylether methacrylate monomer.

29. The stent of claim 24, wherein the second monomer is selected from the group consisting of methylmethacrylate, isobornyl methacrylate, isobutyl methacrylate, perfluoroacetylmethacrylate, tertiary butylmethacrylate, phenylethylmethacrylate, styrene, hydroxyethyl methacrylate, glycerol methacrylate, n-vinyl pyrrolidone and heptadecylfluorodecyl-methacrylate.

30. The stent of claim 24, wherein the first monomer is pentafluoropropylacrylate and the second monomer is heptadecylfluorodecyl methacrylate.

31. The stent of claim 24, which further includes a third monomer of a methacrylic acid ester of polyethyleneoxide, where the ester side chain has a molecular weight of between 200-10,000 Daltons.

32. The stent of claim 29, wherein the third monomer is selected from the group consisting of polyethyleneglycol dimethacrylate, polyethyleneglycol methacrylate and polyethyleneglycol acrylate.

33. The stent of claim 31, wherein the first monomer is butyl acrylate, the second monomer is methylmethacrylate and the third monomer is polyethylene oxide.

34. The stent of claim 31, wherein the first monomer is pentafluoropropylacrylate and the second monomer is methylmethacrylate and the third monomer is polyethylene oxide.

35. The stent of claim 24, which further includes a therapeutic agent.

36. The stent of claim 24, wherein the polymer members are composed of (a) greater than about 40 weight percent of butyl acrylate monomer;

(b) between 3-30 weight percent of methylmethacrylate monomer;

(c) between 2-40 weight percent of polyethylene glycol monomethylether monomethyacrylate;

said monomers when polymerized forming a polymer having a glass transition temperature of less than 25°

C.

37. The stent of claim 36, wherein the polymer forming the polymer members further includes one or more of the following components:

(a) between 0.1-20 weight percent of an organic solvent;

(b) a monomer effective to impart a charge to the polymer at physiologic pH;

(c) between 0.025-0.1 weight percent of a crosslinker;

(d) between 0.1-1 weight percent of a photoinitiator;

(e) a therapeutic agent.

38. The stent of claim 37, wherein the solvent is dimethylformamide in an amount between 1-15 weight percent.

39. The stent of claim 38, further including a therapeutic agent.

40. A stent for insertion into a lumen, comprising;

a radially expandable, support stent having a selected axial length and an outer surface, said stent having rigid regions and flexible regions along its length; and

one or more polymer members coaxially disposed about the outer surface of the support stent, said polymer members positioned over the rigid regions of the support stent, with the flexible regions exposed, and said polymer members being radially expandable with the support stent, and said polymer members composed of

(a) greater than about 40 weight percent of pentafluoropropyl acrylate monomer;

(b) between 3-30 weight percent of (heptadecyl fluorodecyl methacrylate) monomer;

said monomers when polymerized forming a polymer having a glass transition temperature of less than 25°

C.

41. A stent for insertion into a lumen, comprising;

a radially expandable, support stent having a selected axial length and an outer surface, said stent having rigid regions and flexible regions along its length; and

one or more polymer members coaxially disposed about the outer surface of the support stent, said polymer members positioned over the rigid regions of the support stent, with the flexible regions exposed, and said polymer members being radially expandable with the support stent, and said polymer members composed of

(a) greater than about 40 weight percent of pentafluoropropyl acrylate monomer;

(b) between 3-30 weight percent of polyethylene glycol methacrylate monomer or polyethylene glycol monomethylether monomethyacrylate;

(c) between 2-40 weight percent of methylmethacrylate monomer;

said monomers when polymerized forming a polymer having a glass transition temperature of less than 25°

C.

42. The stent of claim 41, further including a therapeutic agent.