Load bearing biocompatible device

• US 20050273178A1
• Filed: 02/07/2005
• Published: 12/08/2005
• Est. Priority Date: 02/06/2004
• Status: Active Grant

• Current Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Kennedy, Stephen J., Boyan, Barbara D., Ku, David N., Guldberg, Robert E.
• Granted Patent: US 7,910,124 B2
• Time in Patent Office: Days
• US Class Current: 623/23.740
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2002/30011 differing in porosity
• CPC Class Codes: A61F 2002/30014 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2002/30784 Plurality of holes
• CPC Class Codes: A61F 2250/0018 differing in elasticity, stiffness or compressibility
• CPC Class Codes: A61F 2250/0023 differing in porosity
• CPC Class Codes: A61L 2430/38 for reconstruction of the spine, vertebrae or intervertebral discs
• CPC Class Codes: A61L 27/52 Hydrogels or hydrocolloids
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: A61P 19/02 for joint disorders, e.g. arthritis, arthrosis

Abstract

Implantable biomaterials, particularly hydrogel substrates with porous surfaces, and methods for enhancing the compatibility of biomaterials with living tissue, and for causing physical attachment between biomaterials and living tissues are provided. Also provided are implants suitable for load-bearing surfaces in hard tissue repair, replacement, or augmentation, and to methods of their use. One embodiment of the invention relates to an implantable spinal disc prosthesis.

Claims

1. An implantable hydrogel substrate comprising a hydrogel surface having a plurality of superficial pores thereon.

2. The hydrogel of claim 1 wherein the pores have an average diameter of between 1 and 100 micrometers.

3. The hydrogel of claim 1 wherein the pores have an average diameter of between 5 to 50 micrometers.

4. The hydrogel of claim 1 wherein the pores have an average diameter of between 10 to 30 micrometers.

5. The hydrogel of claim 1 wherein the superficial pores vary in size by less than 30%.

6. The hydrogel of claim 1, wherein the superficial pores vary in size by less than 10%.

7. The hydrogel of claim 1, wherein the hydrogel is comprised of polyvinyl alcohol.

8. The hydrogel of claim 1, wherein the hydrogel contains a moisture content of at least 5% w/w of the hydrogel.

9. The hydrogel of claim 1, wherein the hydrogel contains a moisture content of at least 30% w/w of the hydrogel.

10. An artificial disc for implantation into the spine comprising the hydrogel substrate of claim 1.

11. The artificial disc of claim 6, wherein the disc is a hydrogel comprising a plurality of regions having variably elasticity.

12. The artificial disc of claim 6, wherein the disc comprises a surface region having a lower modulus of elasticity than an interior region.

13. The artificial disc of claim 6, wherein the disc comprises more than one hydrogel.

14. The artificial disc of claim 9, wherein the disc comprises at least one surface region hydrogel having a higher modulus of elasticity than an interior region hydrogel.

15. A method of making a hydrogel substrate comprising:

a. contacting solid objects with a liquid hydrogel,

b. allowing the aqueous hydrogel to polymerize and crosslink while the solid objects are at least partially immersed in the surface region of the hydrogel, and

c. removing said solid objects from the polymerized and crosslinked hydrogel to form superficial pores thereon.

16. The method of claim 15, wherein the solid objects are polystyrene beads.

17. The method of claim 15, wherein the solid objects are grit, sand, silicon, silica, and ultra-fine particulate matter.

18. The method of claim 15, wherein the solid objects have an average diameter of between 1 to 100 micrometers.

19. The method of claim 15, wherein the solid objects have an average diameter of between 5 to 50 micrometers.

20. The method of claim 15, wherein the solid objects have an average diameter of between 10 and 30 micrometers.

21. The method of claim 15, wherein the solid objects are removed from the hydrogel by using an organic solvent or washing.

22. The method of claim 15, wherein the hydrogel is comprised of polyvinyl alcohol.

23. The method of claim 15, wherein the hydrogel contains a moisture content of at least 5% w/w of the hydrogel

24. The method of claim 15, wherein the hydrogel contains a moisture content of at least 30% w/w of the hydrogel.