RESORBABLE STRUCTURE FOR TREATING AND HEALING OF TISSUE DEFECTS

• US 20060210598A1
• Filed: 05/01/2006
• Published: 09/21/2006
• Est. Priority Date: 07/06/2002
• Status: Abandoned Application

• Current Assignee: Douglas G. Evans, Jeffrey C. Kelly, Todd M. Dewitt
• Original Assignee: Douglas G. Evans, Jeffrey C. Kelly, Todd M. Dewitt
• Inventors: DeWitt, Todd M., Kelly, Jeffrey C., Evans, Douglas G
• Application Number:
  US11/381,037
• Publication Number:
  US 20060210598A1
• Time in Patent Office: Days
• US Class Current: 424/422
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 27/58 Materials at least partially resorbable by the body
• CPC Class Codes: A61L 31/146 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61L 31/148 Materials at least partially resorbable by the body

Abstract

Devices and processes (e.g., improved Plasticized Melt Flow processes (PMF) or improved Phase Separation Polymer Concentration (PSPC), etc.) used to make resorbable and non-resorbable structures for treating and/or healing of tissue defects are disclosed. Among the advantages of using these improved processes are the preservation of molecular weight and the broadening of the processing conditions for temperature sensitive polymers and therapies (e.g. polylactide, polyglycolide, polycaprolactone or Cisplatin, etc.). This reduction in processing temperature, pressure and time can help to preserve the molecular weight and/or integrity of the final product or any additive incorporated therein. Additionally, pore size and shape tailoring can increase the osteoconductive nature of the device.

Claims

1. A porous polymeric device, said device being implantable into a body of a living being to treat tissue or defects therein;

said device comprising a polymer matrix, pores, and at least one modeling agent;

wherein said device comprises a plurality of internal surfaces that define a plurality of said pores, wherein at least said pores are arranged substantially homogeneously throughout said device, wherein said pores are of irregular shapes due to interactions with said at least one modeling agent during processing, and further wherein substantially each of said internal surfaces has expanded at least partially around an external surface of at least one modeling agent, thereby imparting an inward-directed textured or roughened face to said internal surfaces, and wherein said modeling agent is at least partially exposed to said pores, and further wherein said modeling agent chemically reacts upon exposure of said pores to a fluid.

2. The device of claim 1, wherein said modeling agent creates a microporous network.

3. The device of claim 2, wherein, but for said modeling agent, pores interior to an external surface of said device would be closed off from said external surface.

4. The device of claim 1, wherein said modeling agent creates a microporous conduit system between pores.

5. The device of claim 1, wherein said modeling agent modifies at least one mechanical property of said device.

6. The device of claim 1, wherein said modeling agent is arranged to function as an in-vivo leachate to increase overall porosity of said device.

7. The device of claim 1, wherein said pores have a size of at least about 100 microns.

27. The device of claim 1, further comprising at least one polymer matrix-thinning agent comprising at least one metallic stearate selected from the group consisting of the stearates of calcium, magnesium, sodium and zinc.

8. A porous polymeric device, said device being implantable into a body of a living being to treat tissue or defects therein;

said device comprising a polymer matrix, pores, and at least one modeling agent;

wherein said device comprises a plurality of internal surfaces that define a plurality of said pores, said device being manufactured with at least one decompression step;

wherein said pores are of irregular shapes due to interactions with said at least one modeling agent during said decompression step, and specifically wherein during decompression said pores grow in size to an extent where said internal surfaces grow around said at least one modeling agent, thereby modifying the shape of said internal surfaces and causing said modeling agent to chemically react upon exposure of said pores to a fluid.

9. The device of claim 8, wherein said modeling agent creates a microporous network.

10. The device of claim 9, wherein, but for said modeling agent, pores interior to an external surface of said device would be closed off from said external surface.

11. The device of claim 8, wherein said modeling agent comprises a morphology selected from particulate, fibers, platelets and microspheres.

12. The device of claim 8, wherein said modeling agent creates a microporous conduit system between pores.

13. The device of claim 8, wherein said modeling agent is arranged to carry at least one of a drug, a biologically active agent, and a therapeutic agent.

14. The device of claim 8, wherein said modeling agent modifies at least one mechanical property of said device.

15. The device of claim 8, wherein said modeling agent is arranged to function as an in-vivo leachate to increase overall porosity of said device.

16. The device of claim 8, wherein said pores have a size of at least about 100 microns.

17. A porous polymeric device, said device being implantable into a body of a living being to treat tissue or defects therein;

said device comprising a polymer matrix, pores, and at least one modeling agent, and being manufactured with at least one decompression step to expand a pore induction fluid provided to said polymer matrix, thereby shaping at least some of said polymer matrix into the form of walls that define said pores, wherein at least a portion of said pores are induced by expansion of said pore induction fluid during said decompression step, with said pores further being of irregular shape due to interactions with said at least one modeling agent during said decompression step, wherein said modeling agent chemically reacts with a bodily fluid upon exposure to said fluid, and further wherein during decompression said pores grow in size to an extent where said polymeric pore walls stretch around said modeling agent that is or that becomes constrained in its ability to relocate in response to the advancing polymeric pore wall, and thereby provides a textured or roughened face to said pore walls.

18. The device of claim 17, wherein said modeling agent creates a microporous network.

19. The device of claim 18, wherein, but for said modeling agent, pores interior to an external surface of said device would be closed off from said external surface.

20. The device of claim 17, wherein said modeling agent creates a microporous conduit system between pores.

21. The device of claim 17, wherein said modeling agent is arranged to carry at least one of a drug, a biologically active agent, and a therapeutic agent.

22. The device of claim 17, wherein said modeling agent modifies at least one mechanical property of said device.

23. The device of claim 17, wherein said modeling agent is arranged to function as an in-vivo leachate to increase overall porosity of said device.

24. The device of claim 17, wherein said pores have a size of at least about 100 microns.

25. A porous polymeric device, said device being implantable into a body of a living being to treat tissue or defects therein;

said device comprising a polymer matrix, pores, and at least one modeling agent;

wherein said device comprises a plurality of internal surfaces that define a plurality of said pores, said device being manufactured by a process comprising at least one decompression step, wherein at least said pores are arranged substantially homogeneously throughout said device, wherein said pores are of irregular shapes due to interactions with said at least one modeling agent during said decompression step, and further wherein during decompression said pores grow in size to an extent where said internal surfaces attempt to grow around said at least one modeling agent that is in a constrained condition, and do in fact push at least slightly beyond a boundary defined by external surfaces of said modeling agent, thereby modifying the shape of said internal surfaces by creating inwardly-directed protrusions thereon, and wherein still further at least a portion of said internal surfaces are defined by at least a portion of said external surfaces of said modeling agent, thereby imparting an inward-directed textured or roughened face to said internal surfaces, and wherein said modeling agent is at least partially exposed to said pores, and further wherein said modeling agent dissolves upon exposure of said pores to a fluid.

26. A porous polymeric device, said device being implantable into a body of a living being to treat tissue or defects therein;

said device comprising a polymer matrix, pores, and at least one leachable modeling agent;

wherein said device comprises a plurality of internal surfaces that define a plurality of said pores, wherein at least said pores are arranged substantially homogeneously throughout said device, wherein said pores are of irregular shapes due to interactions with said at least one modeling agent during processing, and further wherein substantially each of said internal surfaces has expanded at least partially around an external surface of at least one modeling agent, thereby imparting an inward-directed textured or roughened face to said internal surfaces, and wherein said leachable modeling agent is at least partially exposed to said pores, and further wherein said leachable modeling agent is capable of being leached from said device upon exposure of said pores to a fluid.

28. A porous polymeric device, said device being implantable to treat tissue or defects therein;

said device comprising a polymer matrix, pores, and at least one polymer matrix-thinning agent comprising at least one metallic stearate selected from the group consisting of the stearates of calcium, magnesium, sodium and zinc, wherein said pores are about 50 to 500 microns in diameter.

29. The device of claim 28, wherein at least said matrix polymer further comprises a strengthening agent comprising a non-polymeric material comprising at least one of a ceramic material and a metallic material.

30. The device of claim 29, wherein said non-polymeric material comprises at least one form selected from the group consisting of whiskers, fibers, particulate, and platelets.

31. The device of claim 29, wherein at least a portion of said ceramic material comprises at least one of a calcium phosphate and a calcium sulfate.