Dendrosome-dendriplex inside liposomes: as a gene delivery system

Abstract

Dendrosomes are lipid vesicular entities containing entrapped dendrimer-DNA complexes and possessing low toxicity, acceptable transfection efficiency, and good in vivo tolerance. Herein, an attempt was made to explore the potential of dendrosomes as a gene delivery system combining the advantages of both polyamidoamine (PAMAM) dendrimer (nucleic acid condensation, facilitated endosomal release) and of non-cationic liposomes (increased cellular uptake, low cytotoxicity), and at the same time overcoming the drawbacks of these system (low encapsulation efficiency of non-cationic liposome and toxicity of dendrimers). Dendrosomes were assembled by loading optimized DNA-dendrimer complexes into liposomes prepared by solvating of dried lipid films made of DOPE/EggPC/Cholesterol (4.74:4.75:1.5 mole ratio). Dendrosomes were characterized in terms of size, zeta, encapsulation efficiency and the ability to protect the system from DNA degradation. The transfection efficiency and toxicity of the preparations were evaluated in HeLa cells using flow cytometry and CellTiter-Blue^® methods. The efficient transfection and low toxicity makes them an appealing alternative to be further explored for gene delivery in vivo.

Keywords::

• Dendrosome
• dendriplex
• liposome
• dendrimer
• gene delivery
• non-viral gene therapy
• polymer
• DNA plasmid
• cancer
• transfection
• HeLa cell
• DNA-polymer complex

Acknowledgement

The authors would like to thank Dr. Brigitte Papahadjopoulos-Sternberg (Nano Analytical Laboratory, San Francisco) for the preparation of freeze-fracture electron microscopy micrographs and for her expert help to analyzing them.

Declaration of interest

This work is a part of PhD thesis of S. Movassaghian at Shaheed Beheshti University of Medical Sciences (SBMU), Tehran, Iran and is financially supported by grant No. 400.6302 from SBMU to H.R. Moghimi and F. Shirazi.