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Preparation and magnetic properties of very small magnetite-dextran particles

Assignee: PARTICULATE PROSPECTS CORP
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Filing: 1992-12-02
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Granted: 1994-09-27
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Expires: 2012-12-02
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Abstract

Abstract The present invention is directed to particles comprised of a magnetically responsive material and a dispersant, said particles having a particle size range of about 2 to about 10 nm. The present invention is also directed to a method for the preparation of such particles comprising admixing a magnetically responsive material with a dispersant to form an admixture, and contacting said first admixture with a base for a time period and under conditions appropriate to form a magnetically responsive material-dispersant particle. In a preferred embodiment, the magnetically responsive material is magnetite, the dispersant is dextran, and the base is ammonium hydroxide. In a further preferred embodiment, the admixture is suspended in a gel phase. The present invention is further directed to a method of diagnosis comprising administering to a mammal a contrast effective amount of these particles suspended or dispersed in a physiologically tolerable carrier and generating an NMR image of said mammal.

Inventors

  • 👤 Joseph S. Yudelson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 21:39
CPC Classifications
A; A61; A61K; A61K49/00; A61K49/06; A61K49/18; A61K49/1803; A61K49/1818; A61K49/1821; A61K49/1824; A61K49/1827; A61K49/1851; A61K49/1863; A61K49/1866; B; B82; B82Y; B82Y25/00; B82Y5/00; H; H01; H01F; H01F1/00; H01F1/0036; H01F1/0045; H01F1/0054

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 64 words
A process for the preparation of particles comprised of a magnetically responsive material and a dispersant, said process comprising admixing a magnetically responsive material with a dispersant to form an admixture, suspending said admixture in a gel phase and contacting said admixture in said gel phase with a base for a time period and under conditions appropriate to form a magnetically responsive material-dispersant particle.
Claim 2
Dependent Claim 64 words
A process for the preparation of particles comprised of a magnetically responsive material and a dispersant, said process comprising admixing a magnetically responsive material with a dispersant to form an admixture, suspending said admixture in a gel phase and contacting said admixture in said gel phase with a base for a time period and under conditions appropriate to form a magnetically responsive material-dispersant particle.
Claim 3
Dependent Claim 12 words
The process of claim 1 wherein the magnetically responsive material is magnetite.
Claim 4
Dependent Claim 10 words
The process of claim 1 wherein the dispersant is dextran.
Claim 5
Dependent Claim 20 words
The process of claim 1 wherein said particles have a particle size range of about 2 to about 10 nm.
Claim 6
Dependent Claim 13 words
The process of claim 1 wherein said gel phase is formed by gelatin.
Claim 7
Dependent Claim 14 words
The process of claim 1 wherein said gel phase is formed by polyvinyl alcohol.
Claim 8
Dependent Claim 50 words
A process for the preparation of particles comprised of a magnetically responsive material and a dispersant, said process comprising admixing a magnetically responsive material with a dispersant to form an admixture and contacting said admixture with a base in the vapor phase to form said magnetically responsive material dispersant particle.
Claim 9
Dependent Claim 50 words
A process for the preparation of particles comprised of a magnetically responsive material and a dispersant, said process comprising admixing a magnetically responsive material with a dispersant to form an admixture and contacting said admixture with a base in the vapor phase to form said magnetically responsive material dispersant particle.
Claim 10
Dependent Claim 12 words
The process of claim 7 wherein said magnetically responsive material is magnetite.
Claim 11
Dependent Claim 10 words
The process of claim 7 wherein said dispersant is dextran.
Claim 12
Dependent Claim 19 words
The process of claim 7 wherein said particles have a particle size between about 2 and about 10 nm.
Claim 13
Dependent Claim 11 words
The process of claim 7 wherein said base is ammonium hydroxide.

References Cited (Backward Citations)

US4101435A Cited
US4735796A Cited
US4975282A Cited
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US5219554A Cited
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US5204457A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-09-26 1998-03-28 1998-09-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-09-26 2002-03-28 2002-09-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-09-26 2006-03-28 2006-09-27 $7700.00 Window Closed / Lapsed

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