Physicochemical and in vitro evaluation of cationic liposome, hyaluronic acid and plasmid DNA as pseudo-ternary complexes for gene delivery.

The association of liposome-based gene delivery systems with different biopolymers has been investigated to provide multifunctional properties for its complexes, such as alternative delivery routes and targeting delivery. Hyaluronic acid (HA) is an anionic mucoadhesive biopolymer that can interact to cell surface receptors. In this study, we explored the colloidal formation of pseudo-ternary complexes based on the electrostatic complexation among plasmid DNA (pDNA), cationic liposomes (CL) and hyaluronic acid of low molecular weight (16 kDa). We used extruded cationic liposomes composed of egg phosphatidylcholine (EPC), 1,2-dioleoyl- sn -glycero-3-phosphoethanolamine (DOPE) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) (molar proportion of 2:1:1, respectively), pDNA vector model with luciferase as reporter gene, and HA of low molecular weight of 16 kDa. The pseudo-ternary complexes were physicochemically characterized in terms of their hydrodynamic diameter, polydispersity, zeta potential, morphology and accessibility to pDNA probe. These results together indicated that the pDNA/CL complexes are most likely coated by HA molecules with the pDNA incorporated into the liposomal structure. To evaluate the biological viability of the complexes, we performed in vitro transfections of human epitheloid carcinoma (HeLa) cells. The pDNA/CL/HA complexes presented transfection efficiencies similar to the pseudo-binary pDNA/CL complexes for the different HA amounts studied. In addition, we carried out time-lapse imaging in living HeLa cells so we could monitor the kinetics of complexes internalization. We believe that these results may be useful for future developments of multifunctional nanocarriers that explore the association of materials with different net charge properties for gene delivery and vaccine therapy applications. [ABSTRACT FROM AUTHOR]