US5164187A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydroxyapatite prosthesis coatings
Assignee: KNC NOR Acquisition Sub Inc
•
Filing: 1990-04-05
•
Granted: 1992-11-17
•
Expires: 2010-04-05
Abstract
Abstract Methods and compositions are provided for coating a substrate with a strongly adherent hydroxyapatite coating, which allows for ingrowth of natural bone and strong bonding between the coating and the substrate. The procedure provides for repetitive coatings at varying concentrations of coating forming reagents, where the highest concentration is used initially. The coating has particular application for prostheses, where porous areas of the prostheses are completely coated with a thin sturdy coating of hydroxyapatite.
Inventors
- 👤 Brent R. Constantz
- 👤 Gary C. Osaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:36
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/28; A61L27/30; A61L27/32; A61F; A61F2310/00; A61F2310/00389; A61F2310/00592; A61F2310/00796; Y; Y10; Y10S; Y10S623/00; Y10S623/901
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
214 words
A method for preparing a uniform, strongly adhering, high surface area hydroxyapatite coating to a substrate, said method comprising: contacting a solid substrate with a solution comprising soluble calcium ion and soluble phosphate ion at a first concentration providing for small crystal formation and a high density of nucleation sites forming a first coating on said solid substrate, wherein said calcium ion is at a molar ratio to said phosphate ion of about 1-2:1, and said solid substrate is a metal or hardened plastic; contacting said solid substrate with said small crystal coating with a solution comprising soluble calcium ion and soluble phosphate ion at a second concentration lower than said first concentration providing for a larger crystal formation and a lower density of nucleation sites forming a coating over said first coating, wherein the molarity of the calcium ion is in the range of about 0.05-5 M, the molarity of the phosphate ion is in the range of about 0.01-1 M, and the concentration of the calcium and phosphate ions in said solution is at least 1.5-fold lower than said first concentration; wherein the pH of each of said solutions is in the range of 5-8.5 and the temperature is in the range of 60°-90° C.; and, removing said solid substrate from solution.
Claim 2
Independent Claim
214 words
A method for preparing a uniform, strongly adhering, high surface area hydroxyapatite coating to a substrate, said method comprising: contacting a solid substrate with a solution comprising soluble calcium ion and soluble phosphate ion at a first concentration providing for small crystal formation and a high density of nucleation sites forming a first coating on said solid substrate, wherein said calcium ion is at a molar ratio to said phosphate ion of about 1-2:1, and said solid substrate is a metal or hardened plastic; contacting said solid substrate with said small crystal coating with a solution comprising soluble calcium ion and soluble phosphate ion at a second concentration lower than said first concentration providing for a larger crystal formation and a lower density of nucleation sites forming a coating over said first coating, wherein the molarity of the calcium ion is in the range of about 0.05-5 M, the molarity of the phosphate ion is in the range of about 0.01-1 M, and the concentration of the calcium and phosphate ions in said solution is at least 1.5-fold lower than said first concentration; wherein the pH of each of said solutions is in the range of 5-8.5 and the temperature is in the range of 60°-90° C.; and, removing said solid substrate from solution.
Claim 3
Dependent Claim
27 words
A method according to claim 1, wherein said calcium ion and phosphate ion sources are at a mol ratio of 1.67:1 at concentrations substantially stoichiometric for hydroxyapatite.
Claim 4
Dependent Claim
18 words
A method according to claim 2, wherein said first concentration is from about 2-10 times said second concentration.
Claim 5
Dependent Claim
23 words
A method according to claim 2, further comprising: repeating said contacting a third time at a third concentration lower than said second concentration.
Claim 6
Dependent Claim
15 words
A method according to claim 1, wherein said solutions are flowed past said solid substrate.
Claim 7
Independent Claim
218 words
A method for preparing a strongly adhering hydroxyapatite coating to a substrate, said method comprising: contacting a solid substrate with a solution stream comprising soluble calcium ion and soluble phosphate ion at a temperature in the range of 60-90 degrees C., a pH in the range of about 5-8.5 and at a first concentration, providing for small crystal formation forming a first coating on said solid substrate, wherein said calcium ion is at a molar ratio to said phosphate ion of about 1-2:1, and said solid substrate is a metal or hardened plastic and said calcium ion is introduced into said stream proximal to said solid substrate and said phosphate ion is introduced into said stream distal to said solid substrate; repeating said contacting of said solid substrate with said small crystal coating at least once with a solution comprising soluble calcium ion at a molarity in the range of about 0.05-5 M and soluble phosphate ion at a molarity in the range of about 0.01-1 M and at a temperature in the range of 60-90 degrees C., a pH in the range of about 5-8.5 and at a second concentration at least two-fold lower than said first concentration providing for larger crystal formation forming a coating over said first coating; and removing said solid substrate from solution.
Claim 8
Independent Claim
218 words
A method for preparing a strongly adhering hydroxyapatite coating to a substrate, said method comprising: contacting a solid substrate with a solution stream comprising soluble calcium ion and soluble phosphate ion at a temperature in the range of 60-90 degrees C., a pH in the range of about 5-8.5 and at a first concentration, providing for small crystal formation forming a first coating on said solid substrate, wherein said calcium ion is at a molar ratio to said phosphate ion of about 1-2:1, and said solid substrate is a metal or hardened plastic and said calcium ion is introduced into said stream proximal to said solid substrate and said phosphate ion is introduced into said stream distal to said solid substrate; repeating said contacting of said solid substrate with said small crystal coating at least once with a solution comprising soluble calcium ion at a molarity in the range of about 0.05-5 M and soluble phosphate ion at a molarity in the range of about 0.01-1 M and at a temperature in the range of 60-90 degrees C., a pH in the range of about 5-8.5 and at a second concentration at least two-fold lower than said first concentration providing for larger crystal formation forming a coating over said first coating; and removing said solid substrate from solution.
References Cited (Backward Citations)
US4097935A
Cited
US4705694A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-11-17 | 1996-05-18 | 1996-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-11-17 | 2000-05-18 | 2000-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-11-17 | 2004-05-18 | 2004-11-17 | $7700.00 | Window Closed / Lapsed |