US5205921A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for depositing bioactive coatings on conductive substrates
Assignee: Queen's University
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Filing: 1991-02-04
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Granted: 1993-04-27
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Expires: 2011-02-04
Abstract
Abstract A process for electro depositing bioactive coatings, such as calcium phosphate or aluminum oxide, onto conductive substrates, such as prosthetic implant devices, is described. An electrolyte bath containing an aqueous solution of the desired oxide or phosphate is prepared with an inert anode such as a platinum anode. A porous or non porous substrate, such as a stainless steel or titanium implant is used as the cathode and a D.C. potential is applied so as to raise the interfacial pH at the cathode sufficient to precipitate the desired oxide or phosphate thereon as a dense adherent film.
Inventors
- 👤 Morteza Shirkanzadeh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:55
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/28; A61L27/30; A61L27/32; C; C25; C25D; C25D11/00; C25D11/36; C25D9/00; C25D9/04; C25D9/08; A61F; A61F2310/00; A61F2310/00389; A61F2310/00592; A61F2310/00796
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
104 words
A process for electodepositing an adherent ceramic phosphate coating on a conducting substrate comprising: (a) providing an electrolytic cell having an inert anode and containing an electrolyte comprising an aqueous solution containing ions of said ceramic and having a pH of less than 8; (b) activating said conducting substrate; (c) immersing said conducting substrate in said electrolyte; (d) applying a DC potential between said anode and said activated conducting substrate so as to raise the pH of said electrolyte at an interface between said electrolyte and said activated conducting substrate sufficient to precipitate said ceramic from said electrolyte and onto said activated conducting substrate.
Claim 2
Dependent Claim
104 words
A process for electodepositing an adherent ceramic phosphate coating on a conducting substrate comprising: (a) providing an electrolytic cell having an inert anode and containing an electrolyte comprising an aqueous solution containing ions of said ceramic and having a pH of less than 8; (b) activating said conducting substrate; (c) immersing said conducting substrate in said electrolyte; (d) applying a DC potential between said anode and said activated conducting substrate so as to raise the pH of said electrolyte at an interface between said electrolyte and said activated conducting substrate sufficient to precipitate said ceramic from said electrolyte and onto said activated conducting substrate.
Claim 3
Dependent Claim
17 words
A process as claimed in claim 1 wherein said phosphate coating is a calcium phosphate compound coating.
Claim 4
Dependent Claim
46 words
A process as claimed in claim 3 when said phosphate coating is selected from the group consisting of α and β tricalcium phosphate and components having a formula Ca 5 (PO 4 ) 3-x (CO 3 ) x (OH) 1+x where x is 0.2 or less.
Claim 5
Dependent Claim
30 words
A process as claimed in claim 1 wherein said conducting substrate is selected from stainless steel, titanium and alloys thereof, and a non conducting substrate coated with a conducting layer.
Claim 6
Dependent Claim
22 words
A process as claimed in claim 4 wherein said non conducting substrate is glass and said conducting layer thereon is indium-tin oxide.
Claim 7
Dependent Claim
14 words
A process as claimed in claim 4 wherein said anode is a platinum anode.
Claim 8
Dependent Claim
31 words
A process as claimed in claim 1 wherein said DC potential is in the range of 0.05-10 volts, so as to provide a current density of less than 10 milliamps/sq cm.
Claim 9
Dependent Claim
22 words
A process as claimed in claim 4 wherein said conducting substrate is selected from a porous substrate and a non porous substrate.
Claim 10
Dependent Claim
53 words
A process as claimed in claim 1 including at least one step selected from the group consisting of (a) conducting said process under forced flow conditions (b) subjecting said coated substrate to ultra sonic vibrations and (c) sintering said coated substrate between 300° and 900° C., so as to produce a densified coating.
Claim 11
Dependent Claim
27 words
A process as claimed in claim 1 wherein said electrolyte additionally contains ions selected from fluoride, chloride, carbonate, bicarbonate, nitrate, Pt-group metals, dissolved oxygen and carbon dioxide.
Claim 12
Dependent Claim
18 words
A process as claimed in claim 10 wherein said electrolyte additionally contains collagen or organic biologically non-toxic compounds.
Claim 13
Dependent Claim
29 words
A conducting substrate having deposited thereon a uniform micro-porous, adherent, coating of a ceramic material comprising an interlocking network of non-oriented crystals made by the process of claim 1.
Claim 14
Dependent Claim
17 words
A coated substrate as claimed in claim 12 wherein said coating is doped with CO 3 ions.
Claim 15
Dependent Claim
13 words
A coated substrate as claimed in claim 12 containing co-precipitated biologically active compounds.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-04-26 | 1996-10-26 | 1997-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-26 | 2000-10-26 | 2001-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-26 | 2004-10-26 | 2005-04-27 | $7700.00 | Window Closed / Lapsed |