nystatin-a1 and 1-2-dioleoyloxy-3-(trimethylammonium)propane

DNA condensed agents can improve the transfection efficiency of the cationic liposome delivery system. However, various condensed agents have distinct transfection efficiency and cellular cytotoxicity. The object of this study was to screen the optimal agents with the high transfection efficiency and low cytotoxicity from four polymer compressive materials, polyethylenimine (PEI), chitosan, poly-l-lysine (PLL), and spermidine. DNA was precompressed with these four agents and then combined to cationic liposomes. Subsequently, the entrapment and transfection efficiency of the obtained complexes were investigated. Finally, the particle sizes, cytotoxicity, and endocytosis fashion of these copolymers (Lipo-PEI, Lipo-chitosan, Lipo-PLL, and Lipo-spermidine) were examined. It was found that these four copolymers had significantly lower cytotoxicity and higher transfection efficiency (45.5%, 42.4%, 36.8%, and 47.4%, respectively) than those in the control groups. The transfection efficiency of Lipo-PEI and Lipo-spermidine copolymers were better than the other two copolymers. In 293T cells, nystatin significantly inhibited the transfection efficiency of Lipo-PEI-DNA and Lipo-spermidine-DNA (51.88% and 46.05%, respectively), which suggest that the endocytosis pathway of Lipo-spermidine and Lipo-PEI copolymers was probably caveolin dependent. Our study indicated that these dual-degradable copolymers especially liposome-spermidine copolymer could be used as the potential biocompatible gene delivery carriers.

Topics: Cations; Caveolin 1; Chitosan; Cholesterol; Endocytosis; Fatty Acids, Monounsaturated; HEK293 Cells; Humans; Liposomes; Nystatin; Particle Size; Plasmids; Polyethyleneimine; Polylysine; Quaternary Ammonium Compounds; Spermidine; Transfection

A novel positively charged planar bilayer membrane was formed from a mixture containing 20% cationic lipid, 1,2-dioleoyloxy-3-(trimethylammonio)propane, and neutral phospholipid mixture of 56% phosphatidylethanolamine and 24% egg phosphatidylcholine. The basic properties of the bilayer were essentially the same as those previously reported for neutral and negatively charged lipid bilayers. Using the positively charged bilayer in addition to neutral and negatively charged bilayers, the effects of charge of the planar bilayers upon vesicle-planar membrane fusion were investigated by measuring the fusion, to the bilayers, of liposomes containing nystatin-ergosterol channels and carrying a net negative charge. The tendency for fusion was evaluated in terms of the time elapsed before the first fusion event (denoted fusion time). In the absence of calcium ions, a fusion time of about 1 min was measured with the positively charged planar bilayers, and about 5 and over 15 min with the neutral and negatively charged planar bilayers, respectively. These results indicated that the vesicle-planar membrane fusion without calcium ions is greatly enhanced by the presence of cationic lipids in the planar bilayers, and suggested the usefulness of cationic lipid bilayers.

Topics: Calcium; Calcium Chloride; Cations; Electric Conductivity; Electrochemistry; Ergosterol; Fatty Acids, Monounsaturated; Fluorescent Dyes; Ion Channels; Lipid Bilayers; Liposomes; Membrane Fusion; Nystatin; Phosphatidylcholines; Phosphatidylethanolamines; Phosphatidylserines; Potassium Chloride; Quaternary Ammonium Compounds