Patent US4728575A successfully refreshed from Google Patents.
US4728575A
Expired / Lapsed
US
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Contrast agents for NMR imaging
Assignee: Nexstar Pharmaceuticals Inc
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Filing: 1985-04-10
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Granted: 1988-03-01
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Expires: 2005-04-10
Abstract
Abstract An agent for contrast enhancement in nuclear magnetic resonance imaging is disclosed. Micellular particles such as phospholipid vesicles are associated with or enclose a paramagnetic material. The particles may be formulated with an agent, such as cholestrol, to promote vesicle stability and water exchange across the vesicle bilayer. The vesicles may or may not have antibodies or other cell recognition targeting agents attached to the surface to provide specific targeting. The vesicles provide enhanced target specificity, reduced burden of toxic contrast material and amplified contrast enhancement.
Inventors
- 👤 Ronald C. Gamble
- 👤 Paul G. Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:48
CPC Classifications
A; A61; A61K; A61K51/00; G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/5601; A61K49/00; A61K49/06; A61K49/18; A61K49/1806; A61K49/1812
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
60 words
Magnetic resonance imaging contrast agents for scanning tissue comprising bilayer vesicles with paramagnetic material encapsulated therein, said vesicles formulated with an agent to promote vesicle stability for a sufficient time to allow biodistribution of said vesicles for scanning of said tissue and formulated to permit adequate water proton exchange across the vesicle bilayer to provide contrast for scanning said tissue.
Claim 2
Dependent Claim
60 words
Magnetic resonance imaging contrast agents for scanning tissue comprising bilayer vesicles with paramagnetic material encapsulated therein, said vesicles formulated with an agent to promote vesicle stability for a sufficient time to allow biodistribution of said vesicles for scanning of said tissue and formulated to permit adequate water proton exchange across the vesicle bilayer to provide contrast for scanning said tissue.
Claim 3
Dependent Claim
13 words
The contrast agents of claim 1 in which said micellular particles are vesicles.
Claim 4
Dependent Claim
26 words
The contrast agents of claim 2 in which said vesicles are formulated with an agent to promote vesicle stability and water exchange across the vesicle bilayer.
Claim 5
Dependent Claim
14 words
The contrast agents of claim 3 in which said vesicles are formulated with cholestrol.
Claim 6
Dependent Claim
30 words
The contrast agents of claims 1, 2, 3 or 4 in which antibodies, carbohydrates, or other cell recognition targeting agents are attached to said micellular particles, to provide specific targeting.
Claim 7
Dependent Claim
15 words
The contrast agents of claim 5 in which said targeting agent is the antibody antimyosin.
Claim 8
Dependent Claim
15 words
The contrast agents of claim 5 in which said targeting agent is the antibody antifibrin.
Claim 9
Dependent Claim
31 words
The contrast agents of claims 1, 2 or 3 in which said paramagnetic material is a salt of a transition metal or the lanthanide or actinide series of the Periodic Table.
Claim 10
Dependent Claim
29 words
The contrast agents of claim 7 in which said paramagnetic material is a salt of a paramagnetic ion selected from manganese, copper, gadolinum, erbium, chromium, iron, cobalt and nickel.
Claim 11
Dependent Claim
23 words
The contrast agents of claims 1, 2 or 3 in which said paramagnetic material is a paramagnetic compound including a stable free radical.
Claim 12
Dependent Claim
24 words
The contrast agents of claims 1, 2 or 3 which said paramagnetic material is a paramagnetic compound of a paramagnetic ion and a chelate.
Claim 13
Dependent Claim
25 words
The contrast agents of claims 1, 2, or 3 in which said paramagnetic material is present in a concentration of at least approximately 50 mM.
Claim 14
Dependent Claim
28 words
The contrast agents of claims 1, 2 or 3 in which said paramagnetic material is present in a concentration of from about 50 mM to approximately 1 M.
Claim 15
Dependent Claim
24 words
The contrast agents of claim 10 in which the efficiency of said paramagnetic material is enhanced by the addition of a charged polymer thereto.
Claim 16
Dependent Claim
13 words
The contrast agents of claim 11 in which said charged polymer is poly-L-lysine.
Claim 17
Dependent Claim
74 words
Magnetic resonance imaging contrast agents for scanning tissue comprising phospholipid bilayer esicles with paramagnetic material encapsulated therein, said paramagnetic material being a paramagnetic ion associated with a chelate and said vehicles formulated with an agent to promote vesicle stability for a sufficient time to allow biodistribution of said vesicles for scanning of said tissue and formulated to permit adequate water proton exchange across the vesicle bilayer to provide contrast for scanning of said tissue.
Claim 18
Dependent Claim
74 words
Magnetic resonance imaging contrast agents for scanning tissue comprising phospholipid bilayer esicles with paramagnetic material encapsulated therein, said paramagnetic material being a paramagnetic ion associated with a chelate and said vehicles formulated with an agent to promote vesicle stability for a sufficient time to allow biodistribution of said vesicles for scanning of said tissue and formulated to permit adequate water proton exchange across the vesicle bilayer to provide contrast for scanning of said tissue.
Claim 19
Dependent Claim
14 words
The contrast agents of claim 13 in which said vesicles are formulated with cholestrol.
Claim 20
Dependent Claim
13 words
The contrast agents of claim 14 in which said paramagnetic material is Gd-DTPA.
Claim 21
Dependent Claim
22 words
The contrast agents of claims 18 in which said paramagnetic material is present in a concentration of at least approximately 50 mM.
Claim 22
Dependent Claim
25 words
The contrast agents of claim 19 in which said paramagnetic material is present in a concentration of from about 50 mM to approximately 1 M.
Claim 23
Dependent Claim
62 words
Magnetic resonance imaging contrast agents for scanning tissue comprising bilayer vesicles having a paramagnetic material associated therewith, said vesicles formulated with an agent to promote vesicle stability for a sufficient time to allow biodistribution of said vesicles for scanning of said tissue and formulated to permit adequate water proton exchange across the vesicle bilayer to provide contrast for scanning of said tissue.
Claim 24
Dependent Claim
62 words
Magnetic resonance imaging contrast agents for scanning tissue comprising bilayer vesicles having a paramagnetic material associated therewith, said vesicles formulated with an agent to promote vesicle stability for a sufficient time to allow biodistribution of said vesicles for scanning of said tissue and formulated to permit adequate water proton exchange across the vesicle bilayer to provide contrast for scanning of said tissue.
Claim 25
Dependent Claim
25 words
The contrast agents of claim 21 in which said paramagnetic material is associated with a chelating agent bound to the surface of said micellular particles.
Claim 26
Dependent Claim
12 words
The contrast agents of claim 1 wherein said tissue is tumor tissue.
Claim 27
Dependent Claim
12 words
The contrast agents of claim 16 wherein said tissue is tumor tissue.
Claim 28
Dependent Claim
12 words
The contrast agents of claim 21 wherein said tissue is tumor tissue.
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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) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-01 | 1999-08-31 | 2000-03-01 | $7700.00 | Window Closed / Lapsed |