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US4544545A Expired / Lapsed US ⏱️ 0.0 years remaining

Liposomes containing modified cholesterol for organ targeting

Assignee: University of Massachusetts System
•
Filing: 1983-06-20
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Granted: 1985-10-01
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Expires: 2003-06-20
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Abstract

Abstract Phospholipid liposomes are provided having an outer layer including a cholesterol derivative such as a cholesterol ester and an aqueous medium confined by the layer which includes a tracer agent, a cytoxic agent or a therapeutic agent. The liposomes are adapted for specific organ targeting.

Inventors

  • 👤 Patrick J. Ryan
  • 👤 Michael A. Davis
  • 👤 Donald L. Melchior

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 18:28
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/10; A61K9/127; A61K9/1271; Y; Y10; Y10S; Y10S424/00; Y10S424/812

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 62 words
In a liposome formed by the incapsulation of an active agent by at least one lipid containing bilayer, the improvement comprising a ligand modified cholesterol compound in the lipid of said bilayer, said ligand being positioned at the 3 carbon position of said cholesterol, said ligand modified cholesterol compound rendering the liposome more specific for accumulation at a pre-selected organ in vivo.
Claim 2
Dependent Claim 62 words
In a liposome formed by the incapsulation of an active agent by at least one lipid containing bilayer, the improvement comprising a ligand modified cholesterol compound in the lipid of said bilayer, said ligand being positioned at the 3 carbon position of said cholesterol, said ligand modified cholesterol compound rendering the liposome more specific for accumulation at a pre-selected organ in vivo.
Claim 3
Dependent Claim 12 words
The liposomes of claim 1 wherein said modified cholesterol is cholesterol butyrate.
Claim 4
Dependent Claim 12 words
The liposomes of claim 1 wherein said modified cholesterol is cholesterol phenylacetate.
Claim 5
Dependent Claim 19 words
The liposomes of any one of claims 1, 2 or 3 wherein said lipid bilayer includes a radioactive cation.
Claim 6
Dependent Claim 19 words
The liposomes of any one of claims 1, 2 or 3 wherein said lipid bilayer includes a fluorescent dye.
Claim 7
Dependent Claim 18 words
The liposomes of any one of claims 1, 2 or 3 wherein said lipid bilayer includes gaseous material.
Claim 8
Dependent Claim 18 words
The liposomes of any one of claims 1, 2 or 3 wherein said lipid bilayer includes a drug.
Claim 9
Dependent Claim 18 words
The liposomes of any one of claims 1, 2 or 3 wherein said lipid bilayer includes an enzyme.
Claim 10
Dependent Claim 18 words
The liposomes of any one of claims 1, 2 or 3 wherein said lipid bilayer includes metallic ions.
Claim 11
Dependent Claim 19 words
The liposomes of any one of claims 1, 2 or 3 wherein said lipid bilayer includes a magnetic compound.
Claim 12
Dependent Claim 18 words
The liposomes of any one of claims 1, 2 or 3 wherein said lipid bilayer includes genetic material.
Claim 13
Dependent Claim 20 words
The liposomes of any one of claims 1, 2 or 3 wherein said lipid bilayer includes an antigen or antibody.

References Cited (Backward Citations)

US3932657A Cited
US4310505A Cited
US4343895A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-09-30 1989-04-01 1989-10-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-09-30 1993-04-01 1993-10-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-09-30 1997-04-01 1997-10-01 $7700.00 Window Closed / Lapsed

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