Claims
- 1. A tetracalcium phosphate (TTCP) particle comprising basic calcium phosphate whiskers on a surface of said TTCP particle; said basic calcium phosphate whiskers having a length up to about 5000 nm and a width up to about 500 nm, said basic calcium phosphate whiskers having a Ca/P molar ratio greater than 1.33, and said basic calcium phosphate whiskers having a non-stoichiometric chemical composition.
- 2. The tetracalcium phosphate as defined in claim 1, wherein basic calcium phosphate whiskers have a length from about 1 nm to about 2000 nm and a width from about 1 nm to about 200 nm.
- 3. The tetracalcium phosphate as defined in claim 1, wherein said basic calcium phosphate whiskers have a Ca/P molar ratio from about 1.35 to about 4.0.
- 4. The tetracalcium phosphate as defined in claim 1, wherein said basic calcium phosphate whiskers are substantially free of a hydroxyapatite phase.
- 5. The tetracalcium phosphate as defined in claim 4, wherein said basic calcium phosphate whiskers comprise tetracalcium phosphate as a major phase.
- 6. A process for preparing a tetracalcium phosphate (TTCP) powder comprising TTCP particles comprising basic calcium phosphate whiskers on surfaces of said TTCP particles, said process comprising the following steps:
a) mixing a TTCP powder with a whisker-inducing solution so that basic calcium phosphate whiskers start to grow on surfaces of TTCP particles of said TTCP powder; b) terminating the growth of said calcium phosphate whiskers by drying the whisker-inducing solution in the mixture, so that said calcium phosphate whiskers have a length up to about 5000 nm and a width up to about 500 nm, said basic calcium phosphate whiskers have a Ca/P molar ratio greater than 1.33, and said basic calcium phosphate whiskers have a non-stoichiometric chemical composition.
- 7. The process as defined in claim 6, wherein basic calcium phosphate whiskers have a length from about 1 nm to about 2000 nm and a width from about 1 nm to about 200 nm.
- 8. The process as defined in claim 6, wherein said basic calcium phosphate whiskers have a Ca/P molar ratio from about 1.35 to about 4.0.
- 9. The process as defined in claim 6, wherein said basic calcium phosphate whiskers are substantially free of a hydroxyapatite phase.
- 10. The process as defined in claim 9, wherein said basic calcium phosphate whiskers comprise tetracalcium phosphate as a major phase.
- 11. The process as defined in claim 6, wherein said whisker-inducing solution in step a) is an acidic aqueous solution, a basic aqueous solution, an organic solvent, or substantially pure water.
- 12. The process as defined in claim 11, wherein said whisker-inducing solution in step a) is a basic aqueous solution.
- 13. The process as defined in claim 12, wherein said basic aqueous solution is a diammonium hydrogen phosphate, Na2HPO4, or K2HPO4 aqueous solution.
- 14. The process as define in claim 13, wherein said basic aqueous solution is the diammonium hydrogen phosphate aqueous solution, and said diammonium hydrogen phosphate aqueous solution has a concentration of at least 5 wt %, based on the weight of said solution, and the mixing of said TTCP powder with said diammonium hydrogen phosphate aqueous solution in step a) is in a ratio of less than about 10 g powder per ml solution.
- 15. The process as defined in claim 14, wherein said concentration is 10-60 wt %, and the mixing ratio is less than about 5 g powder per ml solution.
- 16. The process as defined in claim 15, wherein said concentration is about 33 wt %, and the mixing ratio is about 1 gm TTCP per 13 ml solution.
- 17. The process as defined in claim 6, wherein said drying in step b) is carried out by heating the mixture resulting from step a) at a temperature less than about 1000° C.
- 18. The process as defined in claim 6, wherein said drying in step b) is carried out by separating the mixture resulting from step a) and heating the separated powder at a temperature of 50-500° C.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part application of U.S. patent application Ser. No. 10/607,023, filed Jun. 27, 2003, which is a continuation-in-part application of U.S. patent application Ser. No. 10/414,582, filed Apr. 16, 2003, which is a continuation-in-part application of U.S. patent application Ser. No. 09/615,384, filed Jul. 13, 2000, now abandoned, which is a continuation-in-part application of U.S. patent application Ser. No. 09/351,912, filed Jul. 14, 1999, now U.S. Pat. No. 6,379,453B1. The above-listed applications are commonly assigned with the present invention and the entire contents of which are incorporated herein by reference.
Continuation in Parts (4)
|
Number |
Date |
Country |
Parent |
10607023 |
Jun 2003 |
US |
Child |
10773701 |
Feb 2004 |
US |
Parent |
10414582 |
Apr 2003 |
US |
Child |
10607023 |
Jun 2003 |
US |
Parent |
09615384 |
Jul 2000 |
US |
Child |
10414582 |
Apr 2003 |
US |
Parent |
09351912 |
Jul 1999 |
US |
Child |
09615384 |
Jul 2000 |
US |