Synthetic and Biological Vesicular Nano-Carriers Designed for Gene Delivery

Synthetic and biological vesicular carriers have been recognized as attractive and intelligent systems for delivery of a verity of bioactive molecules. The importance of such delivery systems can be mostly due to their physicochemical properties, i.e. a lipid bilayer surrounding an aqueous core which allows encapsulation and protection of active hydrophilic molecules such as nucleic acids. Synthetic vesicles such as liposomes have been studied as gene delivery systems for decades. However, due to their fast clearance, toxicity and immunogenicity which impose restrictions on clinical applications, some other natural lipid vesicles such as exosomes have been considered as alternatives. Attractive features of nature's own 'nano-vesicles' such as exosomes, virosomes, bacterial ghosts and erythrocyte ghosts include efficient cellular entry, physicochemical properties and evading immune responses. Nevertheless, there are advantages and disadvantages with both synthetic and biological vesicular systems. Here, we provide an overview into different vesicle-based gene delivery systems and discuss how various modifications in their structure and formulations could improve the transfection efficiency and decrease the toxicity.