USRE44820EExpiredUtility

Nanocrystalline apatites and composites, prostheses incorporating them, and methods of their production

91
Assignee: YING JACKIE YPriority: Jan 16, 1997Filed: Jun 28, 2012Granted: Apr 1, 2014
Est. expiryJan 16, 2017(expired)· nominal 20-yr term from priority
Inventors:Jackie Y. YingEdward S. AhnAtsuski Nakahira
C04B 2235/5454C04B 2235/608C04B 2235/3232C03C 14/00C04B 2235/80C04B 2235/3217A61F 2310/00239C04B 2235/6562C04B 35/62675C04B 2235/96C04B 2235/5409C04B 2235/3212C04B 35/488C04B 2235/5445A61F 2310/00293C04B 2235/77C04B 2235/6567A61F 2310/00796A61L 27/12C04B 2235/785C04B 2235/3246C04B 35/117C01B 25/32C04B 2235/656C04B 35/46A61L 2400/12C03C 4/0007C04B 35/447C04B 35/6262C04B 2235/549C04B 2235/3225C04B 2235/3244C04B 35/645C04B 2235/668F16C 2240/64B82Y 30/00A61L 27/32C04B 2235/9653Y10S977/776A61F 2/30767C03C 4/0021
91
PatentIndex Score
7
Cited by
79
References
58
Claims

Abstract

Methods for synthesis of nanocrystalline apatites are presented, as well as a series of specific reaction parameters that can be adjusted to tailor, in specific ways, properties in the recovered product. Particulate apatite compositions having average crystal size of less than 150 nm are provided. Products also can have a surface area of at least 40 m 2 /g and can be of high density. Hydroxyapatite material is investigated in particular detail. Compositions of the invention can be used as prosthetic implants and coatings for prosthetic implants.

Claims

exact text as granted — not AI-modified
What is claimed is: 
     
       1. A composition, comprising particulate apatite having an average apatite crystal size of less than 100 nm, wherein the crystal is spherical. 
     
     
       2. The composition of  claim 1  comprising particulate apatite having an average apatite crystal size of less than 50 nm. 
     
     
       3. The composition of  claim 1  comprising particulate apatite having an average apatite crystal size of less than 30 nm. 
     
     
       4. The composition of  claim 1  comprising particulate apatite having an average apatite crystal size of less than 20 nm. 
     
     
       5. A composition as in  claim 1  wherein the particulate apatite is densified. 
     
     
       6. The composition of  claim 1  comprising apatite having an average particle size of less than 1 μm. 
     
     
       7. The composition of  claim 1  comprising apatite having an average particle size of less than 0.5 μm. 
     
     
       8. The composition of  claim 1  comprising apatite having an average particle size of less than 0.25 μm. 
     
     
       9. A composition comprising particulate apatite having a surface area of at least 40 m 2 /g and a spherical crystal. 
     
     
       10. The composition of  claim 7  comprising particulate apatite having a surface area of at least 100 m 2 /g. 
     
     
       11. The composition of  claim 9  comprising particulate apatite having a surface area of at least 150 m 2 /g. 
     
     
       12. The composition of  claim 9  that undergoes apatite phase decomposition of less than 10% when exposed to conditions of at least 1000° C. for at least 2 hours. 
     
     
       13. The composition of  claim 12  that undergoes apatite phase decomposition of less than 5% when exposed to conditions of at least 1000° C. for at least 2 hours. 
     
     
       14. The composition of  claim 12  that undergoes apatite phase decomposition of less than 3% when exposed to conditions of at least 1000° C. for at least 2 hours. 
     
     
       15. The composition of  claim 12  that undergoes apatite phase decomposition of less than 10% when exposed to conditions of at least 1100° C. for at least 2 hours. 
     
     
       16. The composition of  claim 12  that undergoes apatite phase decomposition of less than 5% when exposed to conditions of at least 1100° C. for at least 2 hours. 
     
     
       17. The composition of  claim 12  that undergoes apatite phase decomposition of less than 3% when exposed to conditions of at least 1100° C. for at least 2 hours. 
     
     
       18. The composition of  claim 12  that undergoes apatite phase decomposition of less than 10% when exposed to conditions of at least 1200° C. for at least 2 hours. 
     
     
       19. The composition of  claim 12  that undergoes apatite phase decomposition of less than 5% when exposed to conditions of at least 1200° C. for at least 2 hours. 
     
     
       20. The composition of  claim 12  that undergoes apatite phase decomposition of less than 3% when exposed to conditions of at least 1200° C. for at least 2 hours. 
     
     
       21. The composition of  claim 12  that undergoes apatite phase decomposition of less than 10% when exposed to conditions of at least 1300° C. for at least 2 hours. 
     
     
       22. The composition of  claim 12  that undergoes apatite phase decomposition of less than 5% when exposed to conditions of at least 1300° C. for at least 2 hours. 
     
     
       23. The composition of  claim 12  that undergoes apatite phase decomposition of less than 3% when exposed to conditions of at least 1300° C. for at least 2 hours. 
     
     
       24. An article having a dimension of at least 0.5 cm made up of the composition of  claim 1 . 
     
     
       25. The article of  claim 24  wherein the particulate apatite is consolidated. 
     
     
       26. The article of  claim 24 , formed into the shape of a prosthesis. 
     
     
       27. The article of  claim 24  that is a prosthesis. 
     
     
       28. The article of  claim 24  comprising an exterior coating on a prosthesis. 
     
     
       29. The article of  claim 28  comprising an exterior coating, on a prosthesis, of at least 0.5 micron in thickness. 
     
     
       30. The article of  claim 24  having a theoretical density of at least 90%. 
     
     
       31. The article of  claim 24  having a theoretical density of at least 95%. 
     
     
       32. The article of  claim 24  having a theoretical density of at least 98%. 
     
     
       33. An article having a dimension of at least 0.5 cm made up of the composition of  claim 9 . 
     
     
       34. The article of  claim 33  having a porosity of at least 20%. 
     
     
       35. The article of  claim 33  having a porosity of at least 30%. 
     
     
       36. The article of  claim 33  having a porosity of at least 50%. 
     
     
       37. The article of  claim 33  having a porosity of at least 75%. 
     
     
       38. The densified article of  claim 33  having compressive strength of at least about 150 MPa. 
     
     
       39. The densified article of  claim 38 , having a density of at least about 98%. 
     
     
       40. The densified article of  claim 33  having compressive strength of at least about 500 MPa. 
     
     
       41. The densified article of  claim 33  having compressive strength of at least about 700 MPa. 
     
     
       42. The densified article of  claim 38 , having a density of at least about 90%. 
     
     
       43. The densified article of  claim 38 , having a density of at least about 95%. 
     
     
       44. The article of  claim 24  that is a part of a prosthesis. 
     
     
       45. A composition comprising particulate apatite and an organic species wherein the organic species is a polymer or self-assembled surfactant, said particulate apatite having an average apatite crystal size of less than 100 nm, a crystal aspect ratio ranging from spherical to about 2.9:1, and a surface area of at least about 40 m 2 /g.  
     
     
       46. The composition of claim 45, wherein the particulate apatite has a surface area greater than 60 m 2 /g.  
     
     
       47. The composition of claim 45, wherein the particulate apatite has a surface area greater than 100 m 2 /g.  
     
     
       48. The composition of claim 45, wherein the particulate apatite has an average apatite particle size of less than 0.5 microns.  
     
     
       49. The composition of claim 45, wherein the particulate apatite is consolidated.  
     
     
       50. A composition comprising particulate apatite and an organic species wherein the organic species is a polymer or self-assembled surfactant, said particulate apatite having a crystal aspect ratio ranging from spherical to about 2.9:1 and an average particle size small enough that the composition can be sintered to a density of at least 98% at a temperature of less than about 1100° C.  
     
     
       51. The composition of claim 50, wherein the average particle size is less than 1 μm.  
     
     
       52. The composition of claim 50, wherein the particulate apatite has an average apatite particle size of less than 0.5 microns.  
     
     
       53. The composition of claim 50, wherein the average apatite crystal size is less than 250 nm.  
     
     
       54. The composition of claim 50, wherein the particulate apatite has a surface area greater than 40 m 2 /g.  
     
     
       55. The composition of claim 50, wherein the particulate apatite is consolidated.  
     
     
       56. The composition of claim 50, wherein the particulate apatite is densified.  
     
     
       57. The composition of claim 45, wherein the organic species is a polymer.  
     
     
       58. The composition of claim 50, wherein the organic species is a polymer.

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