Amphoteric liposomes
AssigneeMarina Biotech, Inc.
InventorsSteffen Panzner, Yvonne Kerwitz, Una Rauchhaus, Silke Lutz, Gerold Endert
Life of this patent
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Abstract
A serum-stable mixture of lipids capable of encapsulating an active agent to form a liposome, said mixture comprising phosphatidylcholine and phosphatidylethanolamine in a ratio in the range of about 0.5 to about 8. The mixture may also include pH sensitive anionic and cationic amphiphiles, such that the mixture is amphoteric, being negatively charged or neutral at pH 7.4 and positively charged at pH 4. Amphoteric liposomes comprising such a mixture may be used for encapsulating nucleic acid therapeutics, such as oligonucleotides and DNA plasmids. The drug/lipid ratio may be adjusted to target the liposomes to particular organs or other sites in the body.
Claims14
An amphoteric liposome comprising POPC, MoChol, CHEMS, and DOPE, wherein the amphoteric liposome retains at least 60% of an encapsulated active agent after 4 hours exposure to human serum, wherein MoChol and CHEMS combined comprise 50 to 80 mol % of the amphoteric liposome, wherein POPC and DOPE combined comprise 20 to 50 mol % of the amphoteric liposome, wherein POPC, MoChol, CHEMS, and DOPE combined comprise substantially 100 mol % of the amphoteric liposome, wherein the ratio of DOPE to POPC is from 2 to 4, and wherein the ratio of CHEMS to MoChol is from 0.3 to 0.75.
Dependencies are inferred from the claim text.