Cationic and Ionizable Amphiphiles Based on Dihexadecyl Ester of L-Glutamic Acid for Liposomal Transport of RNA

Various RNAs are among the most promising and actively developed therapeutic agents for the treatment of tumors, infectious diseases and a number of other pathologies associated with the dysfunction of specific genes. Some nanocarriers are used for the effective delivery of RNAs to target cells, including liposomes based on cationic and/or ionizable amphiphiles. Cationic amphiphiles contain a protonated amino group and exist as salts in an aqueous environment. Ionizable amphiphiles are a new generation of cationic lipids that exhibit reduced toxicity and immunogenicity and undergo ionization only in the acidic environment of the cell. In this work we developed a scheme for the preparation and carried out the synthesis of new cationic and ionizable amphiphiles based on natural amino acids (L-glutamic acid, glycine, β-alanine, and γ-aminobutyric acid). Cationic and ionizable liposomes were formed based on the obtained compounds, mixed with natural lipids (phosphatidylcholine and cholesterol), and their physicochemical characteristics (particle size, zeta potential, and storage stability) were determined. Average diameter of particles stable for 5–7 days did not exceed 100 nm. Zeta potential of cationic and ionizable liposomes was about 30 and 1 mV, respectively. The liposomal particles were used to form complexes with RNA molecules. Such RNA complexes were characterized by atomic force microscopy and their applicability for nucleic acid transport was determined.