[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to develop a labile sphingosine-based liposome for intramuscular gene delivery.
Sphingosine-based liposomes were formulated in a range of solutions with phosphatidylcholine, then were associated to DNA. The physico-chemical characteristics of the sphingosine/EPC liposomes and sphingosine/EPC/DNA lipoplexes were determined. DNA stability within sphingosine-based liposomes was evaluated in the presence of a nuclease and mouse serum. In vivo gene transfer was studied by intramuscular injection with and without the electrotransfer technique.
By increasing the charge ratios, colloidally stable sphingosine/DNA particles with a 170 nm average diameter and a positive zeta potential were obtained. Ethidium bromide was still able to insert into plasmid DNA within the lipoplexes, even though plasmid DNA was demonstrated to be complexed to the lipid by gel electrophoresis. Additionally, DNA was shown to be accessible to DNase I, but significantly resistant to serum enzymatic digestion. Upon intramuscular injection, lipoplexes induced an inhibition of gene expression as compared with naked DNA.
The cationic sphingosine/EPC/DNA complexes form weakly compacted structure, potentially labile in vivo, which might be useful for in vivo gene transfer.
Full-text · Article · Sep 2002 · Pharmaceutical Research
[Show abstract][Hide abstract] ABSTRACT: [see structure]. We report the synthesis of new cationic lipids. These amphiphiles present a hydrophobic domain connected to a guanidinium entity by an unsaturated glycoside scaffold. The synthetic strategy using amide or acetal linkage led to various mono- and bicatenar derivatives. Investigation of their physicochemical properties indicated that these new compounds compact DNA.