High-Efficiency Fusogenic Vesicles, Methods of Producing Them, and Pharmaceutical Compositions Containing Them

Abstract

The present invention relates to novel fusogenic vesicles as highly efficient and versatile encapsulation systems for delivering a substance of choice, such as nucleic acids, proteins, peptides, antigens, pharmaceutical drugs and cosmetic agents to cells and tissues.

1 - 38 . (canceled) 
     
     
         39 . A fusogenic vesicle encapsulating at least one therapeutic or immunologically active substance, said fusogenic vesicle comprising a first viral fusion protein derived from influenza virus and a second viral fusion protein derived from influenza virus wherein the second viral fusion protein is capable of causing fusion at a different temperature or a different pH than the first viral fusion protein. 
     
     
         40 . The fusogenic vesicle according to  claim 39 , wherein the first viral fusion protein is inactivated. 
     
     
         41 . The fusogenic vesicle according to  claim 40 , wherein the second viral fusion protein is fusion competent. 
     
     
         42 . The fusogenic vesicle according to  claim 39 , wherein the vesicle is unilamellar. 
     
     
         43 . The fusogenic vesicle according to  claim 39 , wherein the at least one therapeutic or immunologically active substance is selected from the group consisting of DNA, RNA, and siRNA. 
     
     
         44 . The fusogenic vesicle according to  claim 39 , wherein the at least one therapeutic or immunologically active substance is selected from the group consisting of proteins, peptides, amino acids and pharmaceutically active substances. 
     
     
         45 . The fusogenic vesicle according to  claim 39 , wherein the at least one therapeutic or immunologically active substance is selected from the group consisting of a cosmetic agent, a pharmaceutical drug, an antigen or mixtures thereof. 
     
     
         46 . The fusogenic vesicle according to  claim 39 , wherein at least one of the first viral fusion protein or second viral fusion protein is cell type specific. 
     
     
         47 . The fusogenic vesicle according to  claim 39 , wherein at least one of the first viral fusion protein or second viral fusion protein is selected from the group consisting of PR8/34 and A/Singapore HA. 
     
     
         48 . The fusogenic vesicle according to  claim 39 , further comprising lipids derived from the group consisting of glycolipids, phospholipids, cationic lipids, synthetic lipids and cholesterol. 
     
     
         49 . The fusogenic vesicle according to  claim 48 , wherein the lipids comprise POPC and DDAB. 
     
     
         50 . The fusogenic vesicle according to  claim 48 , wherein the lipids are derived from influenza virus. 
     
     
         51 . The fusogenic vesicle according to  claim 39 , wherein the vesicle has a diameter of between 100 and 300 nm. 
     
     
         52 . The fusogenic vesicle according to  claim 39 , further comprising a cell-surface receptor, cytokine, growth-factor, antibody, or antibody fragment. 
     
     
         53 . A method for preparing a fusogenic vesicle comprising fusing a chimeric virosome, wherein the chimeric virosome comprises a first viral fusion protein derived from influenza virus and a second viral fusion protein derived from influenza virus wherein the second viral fusion protein is capable of causing fusion at a different temperature or a different pH than the first viral fusion protein, with a liposome, wherein the liposome encapsulates at least one therapeutic or immunologically active substance to form the fusogenic vesicle. 
     
     
         54 . The method of  claim 53 , further comprising encapsulating at least one therapeutic or immunologically active substance within a liposome. 
     
     
         55 . The method of  claim 53 , further comprising preparing the chimeric virosome by combining the first viral fusion protein and the second viral fusion protein. 
     
     
         56 . The method of  claim 53  further comprising adjusting the size of the fusogenic vesicle such that the fusogenic vesicle has a diameter of between 100 and 300 nm. 
     
     
         57 . A fusogenic vesicle produced by the method of  claim 53 . 
     
     
         58 . A chimeric virosome comprising a first viral fusion protein derived from influenza virus and a second viral fusion protein derived from influenza virus wherein the second viral fusion protein is capable of causing fusion at a different temperature or a different pH than the first viral fusion protein. 
     
     
         59 . The chimeric virosome according to  claim 58  capable of undergoing sequential and separate fusion events.