Patent US5411730A successfully refreshed from Google Patents.
US5411730A
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Magnetic microparticles
Assignee: Research Corp Technologies Inc
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Filing: 1993-07-20
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Granted: 1995-05-02
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Expires: 2013-07-20
Abstract
Abstract Superparamagnetic particles are provided for medical applications including hyperthermia techniques, localized heating and tissue-specific release of therapeutic agents, and magnetic resonance imaging contrast enhancement, comprising superparamagnetic iron oxide and a polymer such as dextran at a ratio of about 0.5 to 0.1 w/w of polymer to iron. The particles display at least one of the following magnetic properties: (a) specific power absorption rate greater than 300 w/g Fe; (b) initial magnetic susceptibility greater than 0.7 EMU/g Fe/Gauss; and (c) magnetic moment greater than 10-15 erg/Gauss.
Inventors
- 👤 Dmitri Kirpotin
- 👤 Daniel C. F. Chan
- 👤 Paul A. Bunn, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:42
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/54; G01R33/56; G01R33/5601; A; A61; A61K; A61K41/00; A61K41/0052; A61K49/00; A61K49/06; A61K49/18; A61K49/1818; A61K49/1821; A61K49/1824; A61K49/1827; A61K49/1851; A61K49/1863; G01R33/4804; Y; Y10; Y10S; Y10S436/00; Y10S436/806; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T436/00; Y10T436/24
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
90 words
A composition comprising particles of an iron oxide and a polymer, said iron oxide being superparamagnetic, the ratio of polymer to iron being 0.1 to 0.5 (w/w), said particles having sedimentation constants in the range of 150-5000S, said particles having at least one of the following magnetic properties: a) specific power absorption rate (SAR) greater than 300 w/g Fe, measured in an electromagnetic field of 1 MHz frequency and 100 Oe field strength; b) initial magnetic susceptibility greater than 0.7 EMU/gFe/Gauss; and c) magnetic moment greater than 10 -15 erg/Gauss.
Claim 2
Dependent Claim
90 words
A composition comprising particles of an iron oxide and a polymer, said iron oxide being superparamagnetic, the ratio of polymer to iron being 0.1 to 0.5 (w/w), said particles having sedimentation constants in the range of 150-5000S, said particles having at least one of the following magnetic properties: a) specific power absorption rate (SAR) greater than 300 w/g Fe, measured in an electromagnetic field of 1 MHz frequency and 100 Oe field strength; b) initial magnetic susceptibility greater than 0.7 EMU/gFe/Gauss; and c) magnetic moment greater than 10 -15 erg/Gauss.
Claim 3
Dependent Claim
11 words
A composition according to claim 1 wherein the polymer is dextran.
Claim 4
Dependent Claim
18 words
A composition according to claim 1 wherein the specific power absorption rate is greater than 350 W/g Fe.
Claim 5
Dependent Claim
13 words
A composition according to claim 1 wherein the polymer-iron ratio is 0.2-0.4 (w/w).
Claim 6
Dependent Claim
17 words
A composition according to claim 1 wherein the particles have sedimentation constants in the range of 500-2500S.
Claim 7
Dependent Claim
22 words
A composition according to claim 1 wherein the particles have at least two of the magnetic properties set forth in claim 1.
Claim 8
Dependent Claim
21 words
A composition according to claim 1 wherein the particles have all three of the magnetic properties set forth in claim 1.
Claim 9
Dependent Claim
24 words
A composition according to claim 3 wherein the particles have at least one of the properties b) and c) set forth in claim 1.
Claim 10
Dependent Claim
14 words
A composition according to claim 1 wherein the particles further comprise a particle-encapsulating lipid.
Claim 11
Dependent Claim
16 words
A composition according to claim 9 wherein the particle-encapsulating lipid comprises an antibody or antibody fragment.
Claim 12
Dependent Claim
20 words
A composition according to claim 9 wherein the particle-encapsulating lipid has a transition temperature in the range of 41°-54° C.
Claim 13
Dependent Claim
15 words
A composition according to claim 11 wherein the particle-encapsulating lipid further comprises a therapeutic agent.
Claim 14
Dependent Claim
38 words
A method for heating a tissue comprising contacting said tissue with the composition of claim 1, then exposing said tissue to an oscillating electro-magnetic field at a frequency of 0.5-1.5 MHz and a field strength of 75-150 Oe.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 7.5 Years (Year 8) | 2002-05-01 | 2002-10-31 | 2003-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-01 | 2006-10-31 | 2007-05-02 | $7700.00 | Window Closed / Lapsed |