Method for making a porous polymeric material

• US 20040219185A1
• Filed: 05/28/2004
• Published: 11/04/2004
• Est. Priority Date: 11/08/2001
• Status: Abandoned Application

• Current Assignee: Kensey Nash Corporation (DSM-Firmenich AG)
• Original Assignee: Kensey Nash Corporation (DSM-Firmenich AG)
• Inventors: Ringeisen, Timothy
• Application Number:
  US10/856,329
• Publication Number:
  US 20040219185A1
• Time in Patent Office: Days
• US Class Current: 424/423
• CPC Class Codes: A61L 2300/114 Nitric oxide, i.e. NO
• CPC Class Codes: A61L 2300/236 Glycosaminoglycans, e.g. heparin, hyaluronic acid, chondroitin
• CPC Class Codes: A61L 2300/252 Polypeptides, proteins, e.g. glycoproteins, lipoproteins, cytokines
• CPC Class Codes: A61L 2300/406 Antibiotics
• CPC Class Codes: A61L 2300/42 Anti-thrombotic agents, anticoagulants, anti-platelet agents
• CPC Class Codes: A61L 2300/43 Hormones, e.g. dexamethasone
• CPC Class Codes: A61L 2300/64 Animal cells
• CPC Class Codes: A61L 2300/802 Additives, excipients, e.g. cyclodextrins, fatty acids, surfactants
• CPC Class Codes: A61L 27/18 obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/48 with macromolecular fillers
• CPC Class Codes: A61L 27/52 Hydrogels or hydrocolloids
• CPC Class Codes: A61L 27/54 Biologically active materials, e.g. therapeutic substances A61L27/227 takes precedence
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: C08J 2201/054 Precipitating the polymer by adding a non-solvent or a different solvent
• CPC Class Codes: C08J 9/28 by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
• CPC Class Codes: C08L 75/04 Polyurethanes
• CPC Class Codes: Y10T 428/1386 Natural or synthetic rubber or rubber-like compound containing
• CPC Class Codes: Y10T 428/139 Open-ended, self-supporting conduit, cylinder, or tube-type article

Abstract

Porous polymers having a plurality of openings or chambers that are highly convoluted, with each chamber being defined by multiple, thin, flat partitions are produced by a new gel enhanced phase separation technique. In a preferred embodiment, a second solvent is added to a polymer solution, the second solvent causing the solution to gel. The gel can then be shaped as needed. Subsequent solvent extraction leaves the porous polymeric body of defined shape. The porous polymers have utility as medical prostheses, the porosity permitting ingrowth of neighboring tissue. The present technique also enhances shape-making capability, for example, of bifurcated vascular grafts, which feature a common entrance region but two or more exit regions.

Claims

1. An implantable prosthesis useful for the repair or replacement of tissues and organs, said prosthesis comprising a first material comprising a polymer comprising walls of large surface area that define a plurality of interconnecting chambers.

2. The prosthesis of claim 1, arranged as a tube or cylinder that defines a lumen.

3. The prosthesis of claim 1, arranged as a flat or concave sheet.

4. The prosthesis of claim 1, further comprising at least one biologically active substance located in said chambers.

5. The prosthesis of claim 2, wherein said tube or cylinder has an inner luminal surface and an outer surface, and further wherein said prosthesis further comprises at least one biologically active substance located on said inner luminal surface.

6. The prosthesis of claim 2, wherein said lumen and said chambers are arranged to carry a biologically active substance.

7. The prosthesis of claim 4, wherein the biologically active substance comprises at least one member selected from the group comprising a physiologically acceptable drug, surfactant, ceramic, hydroxyapatite, tricalciumphosphate, antithrombogenic agent, antibiotic, biologic modifier, glycosaminoglycan, protein, hormone, antigen, virus, cell, and a cellular component.

8. The prosthesis of claim 5, wherein the biologically active substance comprises at least one member selected from the group comprising a physiologically acceptable drug, surfactant, ceramic, hydroxyapatite, tricalciumphosphate, antithrombogenic agent, antibiotic, biologic modifier, glycosaminoglycan, protein, hormone, antigen, virus, cell, and a cellular component.

9. The prosthesis of claim 1, further comprising a second material disposed in said chambers of the first material.

10. The prosthesis of claim 2, wherein said tube or cylinder has an inner luminal surface and an outer surface, and further wherein said prosthesis further comprises a second material located on said inner luminal surface.

11. The prosthesis of claim 9, wherein said second material comprises at least one of collagen, gelatin, succinylated collagen, chondroitin sulfate, succinylated gelatin, chitin, chitosan, cellulose, fibrin, proteins, albumin, alginic acid, heparin, heparin sulfate, hyaluronic acid, termatan sulfate, polymerized alpha hydroxy acid, polymerized hydroxy aliphatic carboxylic acid, and polymerized glycolic acid.

12. The prosthesis of claim 9, wherein the second material comprises a bioabsorbable substance.

13. The prosthesis of claim 12, wherein said bioabsorbable substance is freeze dried to form a microstructure.

14. The prosthesis of claim 13, wherein said microstructure is stabilized.

15. The prosthesis of claim 11, wherein the second material additionally comprises a biologically active substance.

16. The prosthesis of claim 15, wherein the biologically active substance comprises at least one physiologically acceptable drug, surfactant, ceramic, hydroxyapatite, tricalciumphosphate, antithrombogenic agent, antibiotic, biologic modifier, glycosaminoglycan, protein, hormone, antigen, virus, cell, or cellular component.

17. The prosthesis of claim 1, fabricated using a gel enhanced phase separation technique.

18. The prosthesis of claim 1, formed as a repair or replacement for at least one member selected from the group comprising veins, arteries, ureter, bile duct, esophagus, trachea, bladder, intestine, heart, pericardium, stomach, and skin.

19. The prosthesis of claim 1, arranged to patch tissue of hollow organs.

20. The prosthesis of claim 2, wherein the lumen of the tube or cylinder is arranged to facilitate growth of tissue through the lumen.

29. The prosthesis of claim 38, wherein said bioresorbable microstructure comprises at least one of collagen, gelatin, succinylated collagen, chondroitin sulfate, succinylated gelatin, chitin, chitosan, cellulose, fibrin, albumin, alginic acid, heparin, heparin sulfate, hyaluronic acid, termatan sulfate, polymerized alpha hydroxy acid, polymerized hydroxy aliphatic carboxylic acid, or polymerized glycolic acid.

34. The prosthesis of claim 1, wherein said polymeric material comprises at least one reinforcement material.

35. The prosthesis of claim 34, wherein said reinforcement material comprises at least one material selected from the group comprising sutures, fibers and reinforcing rings.

38. The prosthesis of claim 2, further comprising a plurality of said tubes or cylinders that branch.

39. The prosthesis of claim 38, wherein at least one branch has a length or diameter that is different from that of another branch.

40. The prosthesis of claim 38, wherein at least one branch has a diameter that varies along a length of said branch.

21. A prosthesis facilitating growth of cells in a body, said prosthesis comprising a first material comprising a polymer comprising a plurality of walls that bound a plurality of interconnecting chambers, thereby defining a pore structure, said pore structure being arranged such that cells migrate into said prosthesis and form a living tissue barrier.

22. The prosthesis of claim 21, fabricated using a gel enhanced phase separation technique.

23. The prosthesis of claim 21, arranged to form a tube or cylinder that defines a lumen, said tube or cylinder having an inner luminal surface and an outer surface.

24. The prosthesis of claim 23, wherein said outer surface has a more open pore structure than said inner luminal surface.

25. The prosthesis of claim 23, wherein said inner luminal surface and said outer surface are arranged to permit tissue to grow through said prosthesis from said outer surface to said inner surface, and to form a coating along said inner surface.

26. The prosthesis of claim 21, wherein at least one second material is supported within said pore structure of said first material.

27. The prosthesis of claim 26, further comprising a biologically active substance, wherein said biologically active substance is located at at least one of (i) said second material, and (ii) the walls that define the pore structure, said biologically active substance comprising at least one physiologically acceptable drug, surfactant, antithrombogenic agent, antibiotic, biologic modifier, protein, hormone, antigen, virus, cell, or cellular component.

28. A vascular prosthesis, comprising:

a. a polymeric macrostructure having a plurality of large interconnecting chambers in its structure;

b. a stabilized interconnecting bioresorbable microstructure contained within the chambers of the macrostructure; and

c. said vascular prosthesis being made by a gel enhanced phase separation technique.

30. The prosthesis of claim 28, further comprising a biologically active substance, wherein said biologically active substance is located at at least one of (i) said bioresorbable microstructure, and (ii) said macrostructure, said biologically active substance comprising at least one physiologically acceptable drug, surfactant, antithrombogenic agent, antibiotic, biologic modifier, protein, hormone, antigen, virus, cell, or cellular component.

31. A vascular prosthesis to be attached to a vessel, said vascular prosthesis fabricated using a gel enhanced phase separation technique, comprising:

a. a macrostructure comprising a compliant porous polymeric material defining a plurality of interconnecting chambers therethrough; and

b. a stabilized interconnecting bioresorbable microstructure arranged to (i) provide resistance to blood leakage through the chambers of the macrostructure of the prosthesis, and (ii) reduce the prosthesis compliance to approximately that of the attached vessel.

32. The prosthesis of claim 31, wherein after implantation in a body, said bioresorbable microstructure is replaced by host cells that maintain the similarity of compliance between the prosthesis and host vessel.

33. The prosthesis of claim 31, wherein the interconnecting chambers are highly convoluted.

36. The prosthesis of claim 32, arranged as a vascular graft.

37. The prosthesis of claim 36, wherein said vascular graft comprises at least one pair of flaps.