The Synthesis and Transfection Activity of Disulfide Polycationic Amphiphiles.

Some new polycationic amphiphiles containing a disulfide group were synthesized. Cationic liposomes formed from the compounds synthesized and a helper lipid 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine were not toxic for HEK293 and HeLa cells and were highly effective when delivering a fluorescently labeled oligodeoxyribonucleotide. The efficacy of plasmid DNA delivery depended on the cell line and the amphiphile structure, liposomes based on tetracationic amphiphiles being the most effective transfectants. These liposomes can be used for in vitro transfection of eukaryotic cells as well as for further in vivo biological studies.

[Systemic delivery of complexes of melanoma RNA with mannosylated liposomes activates highly efficient murine melanoma-specific cytotoxic T cells in vivo].

The efficiency of the antitumor immune response triggered by dendritic cell (DC)-based vaccines depends predominantly on the efficiency of delivering tumor antigen-coding nucleic acids into DCs. Mannosylated liposomes were used to deliver tumor total RNA into DCs both ex vivo and in vivo, and the cytotoxic T-lymphocyte (CTL) antitumor response was assayed. The liposomes contained the mannosylated lipid conjugate 3-[6-(α-D-mannopyranosyloxy)hexyl]amino-4-{6-[rac-2,3-di(tetradecyloxy)prop-1-yl oxycarbonylamino]hexyl}aminocyclobut-3-en-1,2-dione), the polycationic lipid 2X3 (1,26-bis(cholest-5-en-3ß-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride), and the zwitterionic lipid DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine) at a molar ratio of 1: 3: 6 and were used as a transfection agent. Total RNA isolated from B16-F10 mouse melanoma cells served as a source of tumor antigens. Systemic administration of mannosylated liposomes-tumor RNA complexes into circulation of melanoma-bearing mice induced an efficient CTL response, which reduced the melanoma cell index in vitro with the same efficiency (by a factor of 2.8) as CTLs activated via an inoculation of DCs loaded with complexes of the same composition ex vivo. Complexes of tumor RNA with control liposomes, which lacked the mannosylated lipid conjugate, or DCs transfected with these complexes ex vivo were less efficient and reduced the melanoma cell count by a factor of only 1.6-1.8.

Synthesis and transfection activity of novel galactosylated polycationic lipid.

In this study, we synthesized a new galactosylated cationic lipid and investigated its biological activity. The structure of lipid combines both spermine residue for DNA compaction and galactose moiety for the improvement of aggregation behavior of lipoplexes. Lipid was low toxic for different mammalian cells, and was able both to compact plasmid DNA and to mediate cellular accumulation of various nucleic acids (ODN, pDNA and siRNA) exhibiting biological activity (transgene expression, gene silencing).

[Synthesis of amino analogues of cholic acid].

Amino analogues of cholic acid were synthesized by reduction of oximes with combination of titanium(III) chloride and sodium cyanoborohydride.

[Synthesis of positively charged galactosurfactants].

An approach to synthesis of cationic carbohydrate surfactants with potential antimicrobial or transfected activities is described.

[Synthesis of cationic lipid transfection agents with O,O- or N,O-acetal bonds].

The synthesis of cationic lipids on the basis of 1,2-di-O-tetradecylglycerol is described. The cationic groups represented by the residues of nitrogen-containing heterocyclic bases are attached to the diglyceride backbone through O,O- and N,O-acetal bonds. The resulting lipids can be used as nonviral gene delivery systems to eukaryotic cells.

[Positively charged acyl derivatives of carbohydrates as promising transfection agents].

A convenient approach to the synthesis of mono- and polycationic glycolipid amphiphiles is suggested. The compounds obtained can be used for study of the structure-activity relationship and determination of the effect of hydrophobic and cationic domains on transfection efficiency.

[Synthesis of the alkyl-type glycerolipids with functional groups in their polar domain]. / Sintez glitserolipidov alkil'nogo tipa s funktsional'nymi gruppami v poliarnom domene.

A number of alkyl glycerolipids with short-chain substituents at the C2 atom of glycerol and functional groups (carboxy and amino) in the polar head were synthesized. Cationic alkyl glycerolipids with a hydroxyl function in the hydrophilic moiety were also obtained. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 5; see also http: // www.maik.ru.

[Synthesis of cationic amphiphiles on the basis of deoxycholic acid]. / Poluchenie kationnykh amfifilov na osnove dezoksikholevoi kisloty.

Cationic derivatives of deoxycholic acid with N,N-dimethylenediamine, epsilon-aminocaproic acid, and pyridine as polar heads were synthesized. The cationic groups were linked to 3alpha- and 12alpha-hydroxy groups of the steroid moiety through ester or urethane bonds. Liposomal formulations of the compounds synthesized may be used for gene delivery in cells. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 5; see also http: //www.maik.ru.

[The synthesis of cationic glycerolipid acetals containing aliphatic and heterocyclic bases]. / Sintez kationnykh glitserolipidov atsetal'nogo tipa s alifaticheskimi i geterotsiklicheskimi osnovaniiami.

1,3-Dioxolane series cationic lipids containing residues of aliphatic or heterocyclic nitrogenous bases were synthesized. The bases were attached to the glycerol backbone either directly (piperazine) or via a spacer group through a thioether bond.

[Transfection of eucaryotic cells using cytochrome CYP450 2B6 gene: sensitivity to cyclophosphamide]. / Transfektsiia éukarioticheskikh kletok genom tsitokhroma CYP450 2B6: poiavlenie chuvstvitel'nosti k tsiklofosfamidu.

Sensitivity of 293 human epithelial kidney cells transfected by human cytochrome CYP450 gene to cyclophosphamide was investigated. Transfection was carried out by plasmid DNA containing CYP2B6 gene complexed with cationic liposomes. Liposomes were prepared from mixture of cationic lipids and cholesterol at different molar ratios. Experimental protocol included the following steps: transfection of epithelial kidney cells by complexes of plasmid DNA-cationic liposomes, clone selection in the medium with antibiotic Geneticin G418, selected clone harvesting and their treatment by cyclophosphamide as following cytotoxicity evaluation. It was shown that addition of 0.25 mM of cyclophosphamide resulted in death of 40-45% transfected cell population.