US4078052A
Expired / Lapsed
US
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Large unilamellar vesicles (LUV) and method of preparing same
Assignee: United States Department of Health and Human Services
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Filing: 1976-06-30
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Granted: 1978-03-07
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Expires: 1996-06-30
Abstract
Abstract A process and resulting product for producing large unilamellar phosphatidylserine vesicles (LUV) in the diameter of about 2,000-12,000 A which may additionally encapsulate a drug. The large vesicles are prepared from an initial phosphatidylserine aqueous solution which is subjected to ultrasound or sonicated which produces small unilamellar vesicles (SUV) in the diameter range of 200-500 A. After the addition of calcium ion (Ca 2+ ) in the molar concentration of about 1-10 mM (threshold 1-2 mM) and incubating for 30-60 minutes at room temperature above 10° C and preferably 37° C, intermediate cochleate lipid cylinders form. Finally, addition of a calcium chelating agent such as EDTA or EGTA to these cochleate cylinders produces by fusion the desired large closed spherical unilamellar vesicles (LUV). The intermediate cochleate form appears specific to the phospholipid serine utilized and to the calcium ion (Ca 2+ ) incubating agent. Specific examples of drugs encapsulated in the phosphatidylserine LUV vesicles are Actinomycin D, cyclic 3'5'-adenosine monophosphate, Poly I Poly C, RNA, DNA, and arabinose cytocine and its phosphorylated analogs.
Inventors
- 👤 P. Demetrios Papahadjopoulos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:22
CPC Classifications
A; A61; A61K; A61K9/00; A61K9/10; A61K9/127; A61K9/1277; Y; Y10; Y10S; Y10S436/00; Y10S436/829
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
118 words
A method for preparing large unilamellar phosphatidylserine vesicles with diameters of about 2,000-12,000 A which comprises: (1) subjecting a solution of phosphatidylserine in aqueous NaCl buffer to ultrasound treatment to give a sonicated preparation of said phosphatidylserine containing small spheroidal vesicals in the range of 200-500 A diameter; (2) adding Ca 2+ in the amount of 1-10 mM and incubating for about 30 minutes to 1 hour at room temperature above 10° C to produce large multilamellar structures, a substantial portion of which are cochleate cylinders; (3) adding a chelating agent for Ca 2+ at a pH of about 7.4 in an amount sufficient to chelate surplus calcium to produce the desired large closed spherical unilamellar phosphatidylserine vesicles.
Claim 2
Independent Claim
118 words
A method for preparing large unilamellar phosphatidylserine vesicles with diameters of about 2,000-12,000 A which comprises: (1) subjecting a solution of phosphatidylserine in aqueous NaCl buffer to ultrasound treatment to give a sonicated preparation of said phosphatidylserine containing small spheroidal vesicals in the range of 200-500 A diameter; (2) adding Ca 2+ in the amount of 1-10 mM and incubating for about 30 minutes to 1 hour at room temperature above 10° C to produce large multilamellar structures, a substantial portion of which are cochleate cylinders; (3) adding a chelating agent for Ca 2+ at a pH of about 7.4 in an amount sufficient to chelate surplus calcium to produce the desired large closed spherical unilamellar phosphatidylserine vesicles.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein the addition of Ca 2+ is made by CaCl 2 .
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein the chelating agent is selected from a member of the group consisting of EDTA and EGTA.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein in step 2 the incubation is carried out for about 1 hour at 37° C.
Claim 6
Dependent Claim
14 words
A large unilamellar phosphatidylserine vesicle product produced according to the method of claim 1.
Claim 7
Independent Claim
139 words
A method of preparing large unilamellar phosphatidylserine vesicles with diameter of about 2,000-12,000 A containing an encapsulated drug and which method comprises: (1) subjecting a solution of phosphatidylserine in aqueous NaCl buffer to ultrasound treatment to give a sonicated preparation of said phosphatidylserine containing small spheroidal vesicles in the range of 200-500 A diameter; (2) adding an effective amount of a drug to the solution of phosphatidylserine for encapsulation; (3) adding Ca 2+ in the amount of 1-10 mM and incubating for about 30 minutes to 1 hour at room temperature above 10° C to produce large multilamellar structures, a substantial portion of which are cochleate cylinders; (4) adding a chelating agent for Ca 2+ at a pH of about 7.4 in an amount sufficient to chelate surplus calcium to produce the desired large closed spherical unilamellar phosphatidylserine vesicles.
Claim 8
Independent Claim
139 words
A method of preparing large unilamellar phosphatidylserine vesicles with diameter of about 2,000-12,000 A containing an encapsulated drug and which method comprises: (1) subjecting a solution of phosphatidylserine in aqueous NaCl buffer to ultrasound treatment to give a sonicated preparation of said phosphatidylserine containing small spheroidal vesicles in the range of 200-500 A diameter; (2) adding an effective amount of a drug to the solution of phosphatidylserine for encapsulation; (3) adding Ca 2+ in the amount of 1-10 mM and incubating for about 30 minutes to 1 hour at room temperature above 10° C to produce large multilamellar structures, a substantial portion of which are cochleate cylinders; (4) adding a chelating agent for Ca 2+ at a pH of about 7.4 in an amount sufficient to chelate surplus calcium to produce the desired large closed spherical unilamellar phosphatidylserine vesicles.
Claim 9
Dependent Claim
17 words
The method of claim 6 wherein the addition of Ca 2+ is made by CaCl 2 .
Claim 10
Dependent Claim
22 words
The method of claim 6 wherein the chelating agent is selected from a member of the group consisting of EDTA and EGTA.
Claim 11
Dependent Claim
21 words
The method of claim 6 wherein in step 3 the incubation is carried out for about 1 hour at 37° C.
Claim 12
Dependent Claim
37 words
The method of claim 6 wherein the drug encapsulated is selected from one member of a group consisting of Actinomycin D, cyclic 3'5'-adenosine monophosphate, Poly I Poly C, RNA, DNA, and arabinose cytocine and its phosphorylated analogs.
Claim 13
Dependent Claim
12 words
The method of claim 10 wherein the drug encapsulated is Actinomycin D.
Claim 14
Dependent Claim
13 words
The method of claim 10 wherein the drum encapsulated is cyclic 3'5'-adenosine monophosphate.
Claim 15
Dependent Claim
14 words
The method of claim 10 wherein the drug encapsulated is Poly I Poly C.
Claim 16
Dependent Claim
11 words
The method of claim 10 wherein the drug encapsulated is RNA.
Claim 17
Dependent Claim
11 words
The method of claim 10 wherein the drug encapsulated is DNA.
Claim 18
Dependent Claim
16 words
The method of claim 10 wherein the drug encapsulated is arabinose cytocin and its phosphorylated analogs.
Claim 19
Dependent Claim
14 words
A large unilamellar phosphatidylserine vesicle product produced according to the method of claim 6.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-03-06 | 1981-09-05 | 1982-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-06 | 1985-09-05 | 1986-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-06 | 1989-09-05 | 1990-03-07 | $7700.00 | Window Closed / Lapsed |