Lipophilic pyrylium salts in the synthesis of efficient pyridinium-based cationic lipids, gemini surfactants, and lipophilic oligomers for gene delivery.

Several new classes of pyridinium cationic lipids were synthesized and tested as gene delivery agents. They were obtained through a procedure that generates simultaneously the heterocyclic ring and the positively charged nitrogen atom, using lipophilic pyrylium salts as key intermediates that react with primary amines, yielding pyridinium salts. The choice of the appropriately substituted primary amine, diamine or polyamine, allows the design of the shape of the final lipids, gemini surfactants, or lipophilic polycations.

Pyridinium cationic lipids in gene delivery: an in vitro and in vivo comparison of transfection efficiency versus a tetraalkylammonium congener.

Cationic lipids provide a promising alternative to the use of viruses for delivering genes therapeutically. Among the several classes of lipidic vectors, those bearing a heterocyclic cationic head have shown important advantages, such as low cytotoxicity and improved efficiency across different cell lines. We recently reported a simple and efficient strategy for obtaining pyridinium cationic lipids, starting from pyrylium salts and primary amines.

Pyridinium cationic lipids in gene delivery: a structure-activity correlation study.

Three series of pyridinium cationic lipids useful as nonviral gene delivery agents were prepared by reaction of pyrylium salts with aminodiols, followed by acylation with fatty acyl chlorides. On the basis of this set of compounds, we undertook a comprehensive structure-activity relationship study at the level of the linker, hydrophobic anchor, and counterion in order to identify the structural elements that generate the highest transfection efficiency for this new type of cationic lipid. The results revealed that when formulated with cholesterol at a 1:1 molar ratio, the 1-(1,3-dimyristoyloxyprop-2-yl)-2,4,6-trimethylpyridinium, under the form of hexafluorophosphate (5AMyr) or chloride (5DMyr), was able to transfect NCI-H23 lung carcinoma with efficiencies surpassing classic DOTAP-based formulations and with lower cytotoxicity.

Cationic lipids in gene delivery: principles, vector design and therapeutical applications.

Gene therapy will change medicine by treating the diseases at their core levels revolutionizing the way to deliver functional proteins. The development of this technology relies in designing optimal systems for DNA transfer and expression (transfection), cationic lipids being a promising alternative. Being safer than viral vectors, they also allow the delivery of larger plasmids and can be easily GMP-manufactured and stored.