US5427767A
Expired / Lapsed
US
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Nanocrystalline magnetic iron oxide particles-method for preparation and use in medical diagnostics and therapy
Assignee: Bayer Pharma AG
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Filing: 1992-05-13
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Granted: 1995-06-27
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Expires: 2012-05-13
Abstract
Abstract The invention relates to nanocrystalline magnetic particles consisting of gnetic iron oxide core of Fe 3 O 4 , gamma-Fe 2 O 3 or mixtures thereof and an envelope chemisorbed to said core, the method for preparation of these particles as well as the use thereof in medical diagnostics and/or therapy. The magnetic particles, according to the invention, are characterized by composition of the coating material of natural or synthetic glycosaminoglycans and/or their derivatives with molecular weights of 500 Da to 250,000 Da, if necessary, covalently cross-linked with appropriate cross-linking agents and/or modified by specific additives.
Inventors
- 👤 Mayk Kresse
- 👤 Rudiger Lawaczeck
- 👤 Detlef Pfefferer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:05
CPC Classifications
B; B82; B82Y; B82Y5/00; A; A61; A61K; A61K41/00; A61K41/0052; A61K47/00; A61K47/50; A61K47/69; A61K47/6921; A61K47/6923; A61K47/6927; A61K47/6929; A61K49/00; A61K49/06; A61K49/18; A61K49/1818; A61K49/1821; A61K49/1824; A61K49/1827; A61K49/1833; A61K49/1839; A61K49/1851; A61K49/1863; A61K49/1866; A61K49/189; A61K51/00; A61K51/12; A61K51/1241; A61K51/1244; A61K51/1251; A61K9/00; A61K9/10; A61K9/127; A61K9/1271; A61K9/48; A61K9/50; A61K9/5094; A61K2123/00; G; G01; G01N; G01N2400/00; G01N2400/10; G01N2400/38; G01N2400/40; G01N2446/00; G01N2446/20; G01N2446/30; Y; Y10; Y10T; Y10T436/00; Y10T436/24
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
66 words
Nanocrystalline magnetic particles consisting of a magnetic iron oxide core of FE 3 O 4 , gamma-Fe 2 O 3 or mixtures thereof and a chemisorbed coating on this core, wherein composition of the coating material of natural or synthetic glycosaminoglycans and/or derivatives thereof with molecular weights of 500 Da to 250,000 Da combined, optionally covalently cross-linked by appropriate cross-linking agents and/or modified by specific additives.
Claim 2
Dependent Claim
66 words
Nanocrystalline magnetic particles consisting of a magnetic iron oxide core of FE 3 O 4 , gamma-Fe 2 O 3 or mixtures thereof and a chemisorbed coating on this core, wherein composition of the coating material of natural or synthetic glycosaminoglycans and/or derivatives thereof with molecular weights of 500 Da to 250,000 Da combined, optionally covalently cross-linked by appropriate cross-linking agents and/or modified by specific additives.
Claim 3
Dependent Claim
21 words
Magnetic particles according to claim 1 wherein said particles have core diameters smaller than the dimensions of the magnetic singular domains.
Claim 4
Dependent Claim
40 words
Magnetic particles according to claim 1 wherein said particles optionally are available with the common pharmaceutical adjuvants for injectable solutions and/or enteral agents as stable aqueous colloid dispersive solutions which are 0.2 μm filterable and optionally can be heat sterilized.
Claim 5
Dependent Claim
27 words
Magnetic particles according to claim 1 wherein the natural or synthetic glycosaminoglycans are chondroitin sulfate, dermatan sulfate, heparan sulfate, heparin and synthetic analogues thereof or other heparinoids.
Claim 6
Dependent Claim
31 words
Magnetic particles according to claim 1 wherein the coating material after preparation of enveloped magnetic iron oxide particles, is additionally cross-linked by cross-linkers common in biochemistry and chemistry of natural products.
Claim 7
Dependent Claim
68 words
Diagnostic and/or therapeutic agents comprising optionally isotope doped iron oxide cores of FE 3 O 4 , gamma-Fe 2 O 3 or their mixtures, which are surrounded by a biodegradable coating of natural or synthetic glycosaminoglycans and/or derivatives thereof with molecular weights between 500-250,000 Da, with the coating molecules possibly being cross-linked by cross-linking agents and modified by surface-active substances, targetable structure substances and lower molecular weight residues.
Claim 8
Dependent Claim
68 words
Diagnostic and/or therapeutic agents comprising optionally isotope doped iron oxide cores of FE 3 O 4 , gamma-Fe 2 O 3 or their mixtures, which are surrounded by a biodegradable coating of natural or synthetic glycosaminoglycans and/or derivatives thereof with molecular weights between 500-250,000 Da, with the coating molecules possibly being cross-linked by cross-linking agents and modified by surface-active substances, targetable structure substances and lower molecular weight residues.
Claim 9
Dependent Claim
58 words
Diagnostic and/or therapeutic agents according to claim 6 wherein the natural or synthetic glycosaminoglycans are chondroitin sulfate, dermatan sulfate, heparan sulfate, heparin and their synthetic analogues which are cross-linked by bifunctional cross-linking agents common in biochemistry and chemistry of natural products and/or are cross-linked with mono-, di-, tri-, and oligoamines, synthetic and biological oligopeptides, reduced or oxidized glutathione.
Claim 10
Dependent Claim
24 words
Magnetic particles according to claim 1 wherein the glycosaminoglycan is chondroitin sulfate, keratin sulfate, dermatan sulfate, hyaluronic acid, heparan sulfate or synthetic analog thereof.
Claim 11
Dependent Claim
22 words
Magnetic particles according to claim 1 wherein the glycosaminoglycan is chondroitin sulfate, keratin sulfate, dermatan sulfate, hyaluronic acid, or synthetic analog thereof.
Claim 12
Dependent Claim
19 words
Magnetic particles according to claim 1 wherein the glycosaminoglycan is chondroitin sulfate, keratin sulfate, dermatan sulfate or hyaluronic acid.
Claim 13
Dependent Claim
15 words
Magnetic particles according to claim 1 wherein the glycosaminoglycan is chondroitin sulfate or dermatan sulfate.
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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) | 1998-06-26 | 1998-12-26 | 1999-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-26 | 2002-12-26 | 2003-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-26 | 2006-12-26 | 2007-06-27 | $7700.00 | Window Closed / Lapsed |