Calcium phosphate bone replacement materials and methods of use thereof

• US 20040022825A1
• Filed: 12/20/2002
• Published: 02/05/2004
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: Richard J. Lagow
• Original Assignee: Richard J. Lagow
• Inventors: Lagow, Richard J.
• Granted Patent: US 7,045,105 B2
• Time in Patent Office: Days
• US Class Current: 424/423
• CPC Class Codes: A61F 2/28 Bones joints A61F2/30
• CPC Class Codes: A61F 2002/30957 using a positive or a negative model, e.g. moulds
• CPC Class Codes: A61F 2002/30968 Sintering
• CPC Class Codes: A61F 2310/00293 containing a phosphorus-containing compound, e.g. apatite
• CPC Class Codes: A61F 2310/00359 Bone or bony tissue
• CPC Class Codes: A61L 2430/02 for reconstruction of bones; weight-bearing implants
• CPC Class Codes: A61L 27/12 Phosphorus-containing materials, e.g. apatite
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: C01B 25/32 Phosphates of magnesium, calcium, strontium, or barium
• CPC Class Codes: C04B 2235/3212 Calcium phosphates, e.g. hydroxyapatite
• CPC Class Codes: C04B 2235/44 Metal salt constituents or additives chosen for the nature of the anions, e.g. hydrides or acetylacetonate
• CPC Class Codes: C04B 2235/604 Pressing at temperatures other than sintering temperatures
• CPC Class Codes: C04B 2235/665 Local sintering, e.g. laser sintering
• CPC Class Codes: C04B 2235/667 Sintering using wave energy, e.g. microwave sintering
• CPC Class Codes: C04B 2235/722 Nitrogen content
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 35/447 based on phosphates , e.g. hydroxyapatite
• CPC Class Codes: C04B 35/64 Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F

Abstract

Methods of making porous calcium phosphate bone replacement materials are discussed.

Claims

1. A method of producing a porous calcium phosphate material, comprising:

forming a mixture of calcium ions and phosphate ions having a calcium to phosphorus ratio of 0.1 to 1.67;

heating said mixture to an appropriate reaction temperature; and

cooling the reaction mixture, such that a porous calcium phosphate material is produced.

2. The method of claim 1, wherein said appropriate reaction temperature is about 5°

C. to 150°

C. below the melting point of the mixture.

3. The method of claim 1, further comprising preheating said mixture to 400°

C. to 760°

C. for at least 1 second.

4. The method of claim 3, wherein said mixture is preheated to 400°

C. to 760°

C. for at least 1 second two or more times.

5. The method of claim 1, further comprising compressing said mixture to a pressure of 10,000 psi.

6. The method of claim 1, wherein said ratio of calcium to phosphate ions is about 0.40 to about 0.60.

7. A surgical implant comprising a calcium phosphate material produced by the method of claim 1.

8. A calcium phosphate material produced by the method of claim 1.

9. A method of producing a porous calcium phosphate material comprising:

forming a mixture of calcium ions and phosphate ions;

adding a gas-generating material to said mixture;

heating said mixture an appropriate reaction temperature; and

cooling said mixture such that a solid, porous calcium phosphate material, is produced.

10. The method of claim 9, wherein said gas-generating material is a source of ammonium ions selected from the group consisting of ammonium carbonate, ammonium bicarbonate, ammonium acetate, ammonium hydroxide, ammonium nitrates, ammonium sulfates, ammonium hydrogenphosphate, ammonium dihydrogenphosphate, ammonium fluorophosphates, ammonium citrate, ammonium hydrogencitrate, ammonium hydrogen difluoride, ammonium hydrogen oxalate hemihydrate, ammonium halides, ammonium salts, ammonia anhydride, ammonia solutions, and combinations thereof.

11. A surgical implant comprising a calcium phosphate material produced by the method of claim 9.

12. A calcium phosphate material produced by the method of claim 9.

13. A method of producing a porous calcium phosphate material comprising:

mixing a gas-generating material and a calcium phosphate ceramic precursor;

heating said mixture to below the sintering temperature to generate a gas; and

sintering the calcium phosphate ceramic precursors to make solid ceramic materials, such that a porous calcium phosphate material is produced.

14. The method of claim 13, wherein said calcium phosphate ceramic precursor is monocalcium phosphate hydrate (MCP), dicalcium phosphate hydrate (DCPD), dicalcium phosphate anhydrous (DCPA), octacalcium phosphate pentahydrate (OCP), tricalcium phosphate (TCP), alpha and beta from (hydroxyapatite), pentacalcium hydroxylphosphate (HAP), tetracalcium phosphate monoxide (TCPM), calcium pyrophosphate, calcium metaphosphates, polycalcium metaphospates, or combinations thereof.

15. A method of producing a porous calcium phosphate material comprising subliming a chemical in a reactive calcium phosphate mixture precursor, and reacting the reactive calcium phosphate mixture, to produce a porous calcium phosphate material.

16. A method of producing a porous calcium phosphate material comprising subliming a chemical in one or more calcium phosphate ceramic precursor and sintering the calcium phosphate precursor, to produce a porous calcium phosphate material.

17. A calcium phosphate material, wherein said material is synthetic and comprises pores, wherein said pores have an average size between about 20 μ

m and about 200 μ

m.

18. The calcium phosphate material of claim 17, wherein said material has a bulk density of about 1.0 gm/cm³ to about 2.5 gm/cm³.

19. The calcium phosphate material of claim 17, wherein said material has a porosity of about between about 20% and about 80%.

20. The calcium phosphate material of claim 17, wherein said material has interconnected pores.

21. The calcium phosphate material of claim 17, wherein said material has a compression strength of about 10,000 psi or greater.

22. A method of treating a bone disorder in a subject, comprising applying a calcium phosphate material, to a bone of said subject, such that said bone disorder of said subject is treated, wherein said material is porous and synthetic.

23. A calcium phosphate material, comprising the calcium salt of: