Method for modifying a medical implant surface for promoting tissue growth

• US 20080091234A1
• Filed: 09/26/2007
• Published: 04/17/2008
• Est. Priority Date: 09/26/2006
• Status: Abandoned Application

• Current Assignee: WL Gore and Associates Incorporated (W.L. Gore and Associates)
• Original Assignee: WL Gore and Associates Incorporated (W.L. Gore and Associates)
• Inventors: Kladakis, Stephanie
• Application Number:
  US11/904,482
• Publication Number:
  US 20080091234A1
• Time in Patent Office: Days
• US Class Current: 606/213
• CPC Class Codes: A61B 17/0057 Implements for plugging an opening in the wall of a hollow or tubular organ, e.g. for sealing a vessel puncture or closing a cardiac septal defect sutures A61B17/04; closing rectum or urethra near body surface A61F2/0009
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive
• CPC Class Codes: A61B 2017/00243 cardiac
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/34 Macromolecular materials
• CPC Class Codes: A61L 27/50 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: B29C 59/14 by plasma treatment plasma tubes per se H01J
• CPC Class Codes: C08L 5/10 Heparin; Derivatives thereof
• CPC Class Codes: C08L 67/04 Polyesters derived from hydroxycarboxylic acids, e.g. lactones C08L67/06 takes precedence
• CPC Class Codes: C08L 89/06 derived from leather or skin , e.g. gelatin

Abstract

Disclosed is an occluder for closing an intracardiac defect, such as a patent foramen ovale (PFO), and a method for making the same. The occluder includes a frame and at least one scaffold which are formed from a bioabsorbable polymer, such as poly-4-hydroxybutyrate. The surface of the frame and scaffold are textured to promote cell attachment. Texturing of the surface can be achieved by any number of mechanical or chemical procedures. The device is coated with collagen and heparin which are covalently bound to the surface of the device. The occluder provides improved defect closure compared to other septal occluders known in the art. In particular, the occluder described is specifically designed to improve host cell attachment to and tissue ingrowth over the device when implanted in a patient as compared to the level of host cell attachment and tissue ingrowth achieved with other implantable devices made of bioabsorbable polymers.

Claims

1. An occluder for closing an intracardiac defect, the occluder comprising:

a frame supporting at least one scaffold, said frame and said scaffold being formed from a bioabsorbable polymer, wherein a surface of the scaffold is textured to promote cell attachment, and wherein collagen and heparin are covalently bound to the surface of the scaffold.

2. The occluder of claim 1, wherein a surface of the frame is textured to promote cell attachment, and wherein collagen and heparin are covalently bound to the surface of the frame.

3. The occluder of claim 1, wherein the surface of the scaffold is plasma treated with O₂.

4. The occluder of claim 1, wherein the surface of the scaffold is plasma treated with N₂.

5. The occluder of claim 1, wherein the surface of the scaffold is plasma treated with amine gas.

6. The occluder of claim 5, wherein the surface of the scaffold is also plasma treated with O₂.

7. The occluder of claim 1, where the collagen is Type I collagen.

8. The occluder of claim 7, where the collagen is recombinant human Type I collagen.

9. The occluder of claim 1, where the collagen is Type III collagen.

10. The occluder of claim 9, where the collagen is recombinant human Type III collagen.

11. The occluder of claim 1, wherein the bioabsorbable polymer is poly-4-hydroxybutyrate.

21. A method of closing an intracardiac defect comprising implanting the occluder of claim 1 in a patient.

22. The method of claim 21, where the intracardiac defect is a patent foramen ovale.

12. A method of manufacturing a septal occluder for closing a septal defect, the method comprising the steps of:

forming a septal occluder from a scaffold and frame comprising a bioabsorbable polymer;

texturing the surface of the scaffold; and

covalently binding collagen and heparin to the surface of the scaffold.

13. The method of claim 12, further comprising the steps of texturing the surface of the frame and covalently binding collagen and heparin to the surface of the frame.

14. The occluder of claim 12, wherein the surface of the scaffold is textured by mechanical roughening.

15. The occluder of claim 12, wherein the surface of the scaffold is textured by extrusion and puncturing.

16. The occluder of claim 12, wherein the surface of the scaffold is textured by forming the scaffold in a mold with a roughened surface.

17. The occluder of claim 12, wherein the surface of the scaffold is plasma treated with amine gas.

18. The occluder of claim 17, wherein the surface of the scaffold is also plasma treated with O₂ gas.

19. The method of claim 12, wherein the bioabsorbable polymer is poly-4-hydroxybutyrate.

20. The method of claim 12, wherein the step of covalently binding collagen to the surface of the scaffold occurs separately from the step of covalently binding heparin to the surface of the scaffold.