Medical devices with long term non-thrombogenic coatings

• US 6,120,536 A
• Filed: 06/13/1996
• Issued: 09/19/2000
• Est. Priority Date: 04/19/1995
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Schneider Electric SE
• Inventors: Helmus, Michael N., Ding, Ni
• Primary Examiner(s): Yu, Mickey
• Assistant Examiner(s): Nguyen, Tram A.
• Application Number:
  US08/663,518
• Time in Patent Office: 1,559 Days
• Field of Search: 623/1, 623/11, 623/12, 623/1.15, 623/1.18, 623/1.42, 623/1.43, 623/1.44, 623/1.45, 623/1.46, 606/191, 606/194, 606/195, 604/890.1, 604/891.1, 424/422, 424/423, 424/424, 427/2.1, 427/2.12, 427/2.24, 427/2.21
• US Class Current: 623/1.43
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2/90 characterised by a net-like or mesh-like structure
• CPC Class Codes: A61F 2210/0014 using shape memory or superelastic materials, e.g. nitinol
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: A61L 2300/236 Glycosaminoglycans, e.g. heparin, hyaluronic acid, chondroitin
• CPC Class Codes: A61L 2300/42 Anti-thrombotic agents, anticoagulants, anti-platelet agents
• CPC Class Codes: A61L 2300/602 Type of release, e.g. controlled, sustained, slow
• CPC Class Codes: A61L 2300/606 Coatings
• CPC Class Codes: A61L 2300/622 Microcapsules
• CPC Class Codes: A61L 27/227 Other specific proteins or polypeptides not covered by A61L27/222, A61L27/225 or A61L27/24
• CPC Class Codes: A61L 31/08 Materials for coatings
• 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: A61L 33/0011 Anticoagulant, e.g. heparin, platelet aggregation inhibitor, fibrinolytic agent, other than enzymes, attached to the substrate
• CPC Class Codes: C08L 5/00 Compositions of polysaccharides or of their derivatives not provided for in groups C08L1/00 or C08L3/00
• CPC Class Codes: C08L 71/02 Polyalkylene oxides
• CPC Class Codes: C08L 83/00 Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 83/04 Polysiloxanes
• CPC Class Codes: C08L 83/08 containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen

Abstract

A coating and method for implantable open lattice metallic stent prostheses are disclosed. The coating includes a relatively thin layer of biostable elastomeric material containing an amount of biologically active material, particularly heparin, dispersed in the coating in combination with a non-thrombogenic surface. In one embodiment, the surface is provided with sites of high electronegativity species by coating with fluorosilicone which aid in controlling elution, particularly the initial release rate, and reduced thrombogenic activity. Other non-thrombogenic outer layers for heparin such as covalently bound polyethylene glycol (PEG) are also disclosed.

Claims

1. A medical device having at least a portion which is implantable into the body of a patient, wherein at least a part of the device portion is metallic and at least part of the metallic device portion is covered with a coating for release of at least one biologically active material, wherein said coating comprises an undercoat comprising a hydrophobic elastomeric material incorporating an amount of biologically active material therein for timed release therefrom, and wherein said coating further comprises a topcoat which at least partially covers the undercoat, said topcoat comprising a biostable, non-thrombogenic material which provides long term non-thromobogenicity to the device portion during and after release of the biologically active material, and wherein said topcoat is substantially free of an elutable material.

2. The device of claim 1 wherein said biologically active material is heparin.

3. The device of claim 2 wherein the non-thrombogenic material is selected from the group consisting of fluorosilicone, polyethylene glycol (PEG), polysaccharides, phospholipids and combinations thereof.

4. The device of claim 3 wherein the non-thrombogenic material is fluorosilicone.

5. The device of claim 3 wherein the non-thrombogenic material is polyethylene glycol (PEG).

6. The device of claim 1 wherein the medical device is an expandable stent.

7. The device of claim 1 wherein the topcoat consists of a polymer.

8. The device of claim 6 wherein the stent comprises a tubular body having open ends and an open lattice sidewall structure and wherein the coating conforms to said sidewall structure in a manner that preserves said open lattice.

9. A stent for implantation in a vascular lumen comprising a tubular body having open ends and a sidewall and a coating on at least a part of a surface of said sidewall, said coating further comprising an undercoat comprising a hydrophobic elastomeric material incorporating an amount of finely divided heparin therein for timed release therefrom, and wherein said coating further comprises a topcoat comprising an amount of fluorosilicone which is capable of providing long term non-thrombogenicity to the surface during and after release of the biologically active material, wherein said topcoat at least partially covers the undercoat, and wherein said topcoat is substantially free of an elutable material.

10. The device of claim 9 wherein the sidewall is an open lattice structure and wherein the coating conforms to said sidewall structure in a manner that preserves said open lattice.

11. A stent for implantation in a vascular lumen comprising a tubular body having open ends and a sidewall and a coating on at least a part of the surface of said sidewall, said coating further comprising an undercoat comprising a hydrophobic elastomeric material incorporating an amount of finely divided heparin therein for timed release therefrom, and wherein said coating further comprises a topcoat comprising an amount of polyethylene glycol (PEG) which is capable of providing long term non-thrombogenicity to the surface during and after release of the biologically active material, wherein said topcoat at least partially covers the undercoat, and wherein said topcoat is substantially free of an elutable material.

12. The device of claim 11 wherein the sidewall is an open lattice structure and wherein the coating conforms to said sidewall structure in a manner that preserves said open lattice.