Compressed porous materials suitable for implant

• US 8,445,554 B2
• Filed: 05/24/2010
• Issued: 05/21/2013
• Est. Priority Date: 04/29/2004
• Status: Active Grant

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: Kensey Nash Corporation (DSM-Firmenich AG)
• Inventors: Ringeisen, Timothy A., Turner, Amanda, DeMeo, Joseph, Hearn, Patrick E., McDade, Robert L.
• Primary Examiner(s): ZEMEL, IRINA SOPJIA
• Application Number:
  US12/785,949
• Publication Number:
  US 20100305712A1
• Time in Patent Office: 1,093 Days
• Field of Search: 521/50, 521/52, 623/17.11
• US Class Current: 521/50
• CPC Class Codes: A61B 17/0642 for bones, e.g. for osteosynthesis or connecting tendon to bone
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/846 Nails or pins, i.e. anchors without movable parts, holding by friction only, with or without structured surface A61B17/72, A61B17/86 take precedence
• CPC Class Codes: A61B 17/866 Material or manufacture
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30032 differing in absorbability or resorbability, i.e. in absorption or resorption time
• CPC Class Codes: A61F 2002/30036 differing in release or diffusion time
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30563 having elastic means or damping means, different from springs, e.g. including an elastomeric core or shock absorbers
• CPC Class Codes: A61F 2002/30578 having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30677 Means for introducing or releasing pharmaceutical products, e.g. antibiotics, into the body
• CPC Class Codes: A61F 2002/30904 serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/3092 having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/30971 Laminates, i.e. layered products
• CPC Class Codes: A61F 2310/00293 containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/0097 Coating or prosthesis-covering structure made of pharmaceutical products, e.g. antibiotics
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges

Abstract

A high strength porous polymeric material manufactured by a compression process is disclosed. The material results in a network of interconnected collapsed pores, which forces thin overlapping walls and passages to be created. The network provides permeable access for fluid migration throughout the material. The strength and/or permeability are advantageous for medical devices and implants.

Claims

1. A porous implantable device suitable for implantation in a living being, said implantable device comprising a high density porous polymer material having at least one property that is characteristic of at least one of cortical bone and cancellous bone of a human being, said at least one property being selected from the group consisting of compressive strength, modulus of elasticity, and tensile strength, wherein said high density is obtained by a process comprising compression applied to at least one porous polymer material, wherein said compression process causes the sacrifice of at least some pores in said porous polymer material, thereby forming a new shape, and further wherein said compression takes place in at least one of (i) a temperature above the glass transition temperature for said polymer, and (ii) when said polymer is in a plasticized condition, whereby molecules of said polymer move and rotate to achieve a lower energy state, thereby causing said high density porous material to permanently lock in the new shape, and wherein said device is arranged for implantation into said living being.

2. The porous implantable device of claim 1, wherein said at least one polymer material is resorbable.

3. The porous implantable device of claim 1, wherein said pores are sacrificed to create laminar walls.

4. The porous implantable device of claim 1, wherein said high density porous material is further machined to a final shape.

5. The porous implantable device of claim 1, further comprising at least one additive component.

6. The porous implantable device of claim 5, wherein said additive component is distributed uniformly throughout the implantable device.

7. The porous implantable device of claim 5, wherein said additive component is distributed on outside surfaces of the implantable device.

8. The porous implantable device of claim 5, wherein said additive component is distributed within said pores of said implantable device.

9. The porous implantable device of claim 5, wherein said additive component is distributed in a portion of said implantable device.

10. The porous implantable device of claim 5, wherein said additive component is arranged to create a microstructure.

11. The porous implantable device of claim 10, wherein said microstructure is arranged to encourage tissue ingrowth.

24. The porous implantable device of claim 1, wherein said bone comprises a bone from at least one location selected from the group consisting of an iliac crest, a spine, a chin, a cheek and a skull.

25. The porous implantable device of claim 1, wherein said sacrifice of said at least some pores creates overlapping laminate walls in said high density porous polymer material.

28. The porous implantable device of claim 1, wherein said human being is a mature human being.

12. A high density porous material comprising at least some sacrificed pores, suitable for implantation into a living being, having at least one mechanical property being at least characteristic of at least one of cortical bone and cancellous bone of a human being, said at least one property being selected from the group consisting of compressive strength, modulus of elasticity, and tensile strength, and being obtained by the process comprising the steps of:

a) providing at least one high porosity polymer material comprising a plurality of pores in the form of cells, wherein said pores are defined by pore walls;

b) inducing a glass-transition state within said at least one high porosity polymer material;

c) applying a compressive force within one or more dimensions while said high porosity polymer material is in said glass transition state, said compressive force being sufficient to cause said molecules of said high porosity polymer material to move and rotate to achieve a lower energy state, thereby causing said high porosity polymer material to achieve a new size or shape, and further to sacrifice at least a portion of said pores, thereby creating said high density porous polymer material; and

d) cooling said high density porous polymer material out of said glass transition state, wherein said high density porous polymer material permanently maintains the new shape or size.

13. The high density porous implantable material of claim 12, wherein said at least one polymer material is resorbable.

14. The high density porous implantable material of claim 12, wherein said process further comprises the step of:

e) machining said high density porous material to a shape.

15. The high density porous implantable material of claim 12, wherein said high porosity material further comprises at least one additive component.

16. The high density porous implantable material of claim 15, wherein said additive component is distributed uniformly throughout said high porosity material.

17. The high density porous implantable material of claim 15, wherein said additive component is distributed on outside surfaces of said high porosity material.

18. The high density porous implantable material of claim 15, wherein said additive component is distributed within said pores of said high porosity material.

19. The high density porous implantable material of claim 15, wherein said additive component is distributed in a portion of said high porosity material.

20. The high density porous implantable material of claim 15, wherein said additive component is arranged to create a microstructure.

21. The high density porous implantable material of claim 20, wherein said microstructure is arranged to encourage tissue ingrowth.

22. A porous implantable device comprising a porous polymer that is compressed by at least about 40 percent and no more than about 87 percent of its original height while in a state of glass transition or pseudo glass transition, is arranged to maintain its compressed shape, and has at least one mechanical property being at least characteristic of bone of a human being, said at least one mechanical property being selected from the group consisting of compressive strength, modulus of elasticity, and tensile strength.

23. The porous implantable device of claim 22, wherein said bone comprises at least one of cortical bone and cancellous bone.

26. The porous implantable device of claim 22, wherein said porous polymer comprises pores, and further wherein said pores define pore walls, and still further wherein said compression causes collapse of at least some of said pores, thereby forming overlapping laminate walls in said porous polymer.

27. The porous implantable device of claim 22, wherein said bone comprises a bone from at least one location selected from the group consisting of an iliac crest, a spine, a chin, a cheek and a skull.