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US5074916A
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Alkali-free bioactive sol-gel compositions
Assignee: FLORIDA UNVERSITY OF
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Filing: 1990-05-18
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Granted: 1991-12-24
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Expires: 2010-05-18
Abstract
Abstract Sol-gel processing techniques are used to produce alkali-free bioactive glass compositions based on SiO2, CaO and P2O5. By varying the SiO2 content, a range of hydroxyapatite production rates can be obtained; conversely, varying the time of exposure to actual or simulated in vivo solutions permits use of a range of allowable proportions of SiO2. The sol-gel derived compositions can be chosen to achieve target values for thermal expansion coefficient, elastic modulus and volume electrical resistivity.
Inventors
- 👤 Larry L. Hench
- 👤 Arthur E. Clark
- 👤 Rounan Li
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:44
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/28; A61L27/30; A61L27/32; A61L27/02; A61L27/12; C; C03; C03C; C03C1/00; C03C1/006; C03C3/00; C03C3/04; C03C3/076; C03C3/097; C03C4/00; C03C4/0007; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00293; A61F2310/00389; A61F2310/00592; A61F2310/00796
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
51 words
A bioactive composition prepared using a sol-gel process, and consisting essentially of more than 60 but no more than 86 weight percent SiO 2 , at least 4 but less than 33 weight percent CaO and at least 3 but no more than 15 weight percent P 2 O 5 .
Claim 2
Dependent Claim
51 words
A bioactive composition prepared using a sol-gel process, and consisting essentially of more than 60 but no more than 86 weight percent SiO 2 , at least 4 but less than 33 weight percent CaO and at least 3 but no more than 15 weight percent P 2 O 5 .
Claim 3
Dependent Claim
18 words
The composition of claim 1 wherein the bioactive glass forms a hydroxyapatite layer upon exposure to body fluids.
Claim 4
Dependent Claim
18 words
The composition of claim 1, wherein the bioactive glass is produced as a powder using a sol-gel process.
Claim 5
Dependent Claim
18 words
The composition of claim 1, wherein the bioactive glass is produced as a monolith using a sol-gel process.
Claim 6
Dependent Claim
18 words
The composition of claim 1, wherein the bioactive glass is produced as a coating using a sol-gel process.
Claim 7
Dependent Claim
95 words
A bioactive glass powder consisting essentially of SiO 2 , CaO and P 2 O 5 , prepared using a sol-gel process, and having pores with a diameter range of from about 1.2 to about 10 nm and a surface area of at least 200 m 2 /g, wherein the weight percentage of SiO 2 is more than 60 but no more than 86, the weight percentage of CaO is at least 4 but less than 33, and the weight percentage of P 2 O 5 is at least 3 but no more than 15.
Claim 8
Dependent Claim
95 words
A bioactive glass powder consisting essentially of SiO 2 , CaO and P 2 O 5 , prepared using a sol-gel process, and having pores with a diameter range of from about 1.2 to about 10 nm and a surface area of at least 200 m 2 /g, wherein the weight percentage of SiO 2 is more than 60 but no more than 86, the weight percentage of CaO is at least 4 but less than 33, and the weight percentage of P 2 O 5 is at least 3 but no more than 15.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-23 | 1995-06-24 | 1995-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-23 | 1999-06-24 | 1999-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-23 | 2003-06-24 | 2003-12-24 | $7700.00 | Window Closed / Lapsed |