Bone cement composition and method of making the same

• US 20070048382A1
• Filed: 08/29/2005
• Published: 03/01/2007
• Est. Priority Date: 08/29/2005
• Status: Active Grant

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: Kyphon SARL (Medtronic Plc)
• Inventors: Wenz, Robert, Meyer, Jorg
• Granted Patent: US 7,651,701 B2
• Time in Patent Office: Days
• US Class Current: 424/487
• CPC Class Codes: A61K 31/66 Phosphorus compounds
• CPC Class Codes: A61K 38/18 Growth factors; Growth regulators
• CPC Class Codes: A61L 24/0084 containing fillers of phosphorus-containing inorganic compounds, e.g. apatite
• CPC Class Codes: A61L 24/04 containing macromolecular materials
• CPC Class Codes: A61L 2430/02 for reconstruction of bones; weight-bearing implants
• CPC Class Codes: A61P 19/08 for bone diseases, e.g. rachitism, Paget's disease

Abstract

Disclosed herein is a composition suitable for use in spinal surgery. The composition generally includes a reaction product or settable mixture of first and second components, the first component including a spray-dried inorganic filler, a radical donor, and a pre-polymerized vinyl polymer, and the second component including a radical scavenger, a diluent, a polymerization accelerator, and a reactive monomer. Furthermore, disclosed herein is a method of making the composition, which generally includes mixing the first and second components under conditions suitable to form a curable reaction product.

Claims

1. A composition comprising a reaction product of:

(a) a first component comprising a spray-dried inorganic filler, a radical donor, and a pre-polymerized vinyl polymer; and

,

(b) a second component comprising a radical scavenger, a diluent, a polymerization accelerator, and a reactive monomer.

2. The composition of claim 1, wherein the first component and second component are present in a weight ratio of about 2.2:

1 to about 3.3;

1.

3. The composition of claim 1, wherein the first component further comprises an optional ingredient selected from the group consisting of an antibiotic, a cytostatic agent, an analgesic agent, a disinfectant, a preservative, a growth factor, a proliferative factor, a protein, a peptide, a biopolymer, an imageable marker, a dye, and mixtures thereof.

4. The composition of claim 2, wherein the imageable marker is selected from the group consisting of barium sulfate (BaSO₄), zirconium dioxide, CHI₃, Na₂FPO₃, and CaF_2,, and mixtures thereof.

5. The composition of claim 1, wherein,the second component further comprises an optional ingredient selected from the group consisting of a dye, an admixture of proteins, a chemotherapeutic, a drug, an antibiotic, and mixtures thereof.

6. The composition of claim 5, wherein the admixture of proteins is selected from the group consisting of mitogenic growth factors, morphogenic growth factors, and mixtures thereof.

7. The composition of claim 5, wherein the drug is a bisphosphonate.

8. The composition of claim 1, wherein the spray-dried inorganic filler comprises a sintered, spray-dried inorganic filler.

9. The composition of claim 1, wherein the spray-dried inorganic filler is spray-dried hydroxyapatite.

10. The composition of claim 9, wherein the spray-dried, modified hydroxyapatite is sintered, spray-dried hydroxyapatite.

11. The composition of claim 1, wherein the radical donor is selected from the group consisting of benzoyl peroxide (BPO), azo-bis-isobutyrylnitrile (AIBN), and mixtures thereof.

12. The composition of claim 1, wherein the pre-polymerized vinyl polymer is selected from the group consisting of poly(methyl methacrylate) (PMMA), prepolymerized styrene acrylates, poly-methacrylate, poly-ethacrylate, poly-butylmethacrylate, and copolymers thereof, and mixtures thereof.

13. The composition of claim 12, wherein the pre-polymerized vinyl polymer is PMMA.

14. The composition of claim 12, wherein the pre-polymerized vinyl polymer comprises beads having an average particle size of about 20 micrometers (μ

m) to about 55 μ

m.

15. The composition of claim 1, wherein the radical scavenger is selected from the group consisting of hydroquinone, hydroquinone monomethylether, vitamin E, and mixtures thereof.

16. The composition of claim 1, wherein the diluent is selected from the group consisting of polyethylene glycol (PEG), an ester of mellitic acid, and mixtures thereof.

17. The composition of claim 16, wherein the ester of mellitic acid is tri-octylmellitic ester.

18. The composition of claim 16, wherein the diluent has a molecular weight such that the diluent is a liquid at standard temperature and pressure.

19. The composition of claim 16, wherein the PEG has a molecular weight of about 100 to about 1000.

20. The composition of claim 19, wherein the PEG has a molecular weight of about 400 to about 800.

21. The composition of claim 1, wherein the reactive monomer is selected from the group consisting of methyl methacrylate (MMA), PEG monoacrylates, PEG diacrylates, PEG monomethacrylates, PEG dimethacrylates, PEG-mono/di-acrylate/methacrylate, butanediol methacrylates, polyolefin-acrylates, urethaneacrylates, methacrylates, and mixtures thereof.

22. The composition of claim 21, wherein the reactive monomer is MMA.

23. The composition of claim 21, wherein the PEG monoacrylates, PEG diacrylates, PEG monomethacrylates, PEG dimethacrylates have a molecular weight in a range of about 200 Daltons (D) to about 1500 D.

24. The composition of claim 1, wherein the polymerization accelerator is selected from the group consisting of dimethyl aniline, diethyl aniline, dimethylparatoluidine (DMPT), diethylparatoluidine, and mixtures thereof.

25. The composition of claim 24, wherein the polymerization accelerator is selected from the group consisting of dimethylparatoluidine (DMPT) and dihydroxyethylorthotoluidine, and mixtures thereof.

26. The composition of claim 25, wherein the polymerization accelerator is DMPT.

27. The composition of claim 1, wherein the first component comprises about 0.5 wt. % to about 99.5 wt. % of the spray-dried inorganic filler, based on the total weight of the first component.

28. The composition of claim 1, wherein the first component comprises about 0.5 wt. % to about 5 wt. % of a radical donor, based on the total weight of the spray-dried inorganic filler and the pre-polymerized vinyl polymer.

29. The composition of claim 1, wherein the first component comprises about 0.5 wt. % to about 99.5 wt. % of pre-polymerized vinyl polymer, based on the total weight of the first component.

30. The composition of claim 2, wherein the imageable marker is present in the first component and comprises up to about 30 wt. % of the first component, based on the total weight of the first component.

31. The composition of claim 1, wherein the radical scavenger comprises about 5 parts per million parts of the second component (ppm) to about 500 ppm.

32. The composition of claim 1, wherein the second component comprises about 1 wt. % to about 90 wt. % of the diluent, based on the total weight of the second component.

33. The composition of claim 1, wherein second component comprises about 0.1 wt. % to about 3 wt. % of the polymerization accelerator, based on the total weight of the second component.

34. The composition of claim 1, wherein the second component comprises about 10 wt. % to about 99 wt. % of reactive monomer, based on the total weight of the second component.

35. A composition comprising a settable mixture of:

(a) a first component comprising a spray-dried inorganic filler, a radical donor, and a pre-polymerized vinyl polymer;

(b) a second component reactive with the first component, the second component comprising a radical scavenger, a diluent, a polymerization accelerator, and, a reactive monomer.

36. A method of making a bone cement composition, the method comprising mixing

(a) a first component comprising a spray-dried inorganic filler, a radical donor, and a pre-polymerized vinyl polymer;

and

(b) a second component comprising a radical scavenger, a diluent, a polymerization accelerator, and a reactive monomer, under conditions suitable to form a curable reaction product.

39. The method of claim 36, wherein the spray-dried inorganic filler comprises a sintered, spray-dried inorganic filler prepared by combining an inorganic filler with an organic solvent to form a mixture, spray drying the mixture, and sintering the spray-dried mixture.

37. The method of claim 37, further comprising curing the reaction product.

38. The method of claim 37, further comprising mixing the first and second components in a weight ratio of the first component to the second component of about 1:

3 to about 1;

2.

40. A kit comprising

(a) a packaged first component comprising a spray-dried inorganic filler, a radical donor, and a pre-polymerized vinyl polymer;

and,

(b) a packaged second component comprising a radical scavenger, a diluent, a polymerization accelerator, and a reactive monomer.

41. The kit of claim 40 further comprising an apparatus suitable to mix the first and second components.

42. The kit of claim 40 further comprising an apparatus suitable to deliver a mixture of the first and second components to a surgical site.