Amino acid-based liposomal assemblies: Intracellular plasmid DNA delivery nanoparticles

Due to the limitations of viral vectors with regard to the cytotoxicity and immunogenicity, nonviral vectors, especially cationic liposomes, have been thoroughly investigated for gene therapy both in vitro and in vivo. In this review, the influence of structure-activity relationship of various amino acid-based cationic lipids with respect to in vitro gene delivery efficiencies has been discussed. Cationic lipids have been extensively investigated to explore the parameters responsible for influencing the gene delivery efficiencies so that lipid structures for efficient gene delivery can be designed for both in vitro and in vivo applications. The morphology and the physicochemical properties of the cationic lipid assemblies are influenced by different parts of the cationic lipids such as the ionization states and the structure of the hydrophilic head group, nature and length of the spacers between the hydrophilic head group and the hydrophobic moiety, and type and length of the hydrophobic alkyl chains.