Cationic niosomes composed of spermine-based cationic lipids mediate high gene transfection efficiency

Non-ionic surfactant-based vesicles (niosomes) composed of non-ionic surfactants (i.e., Tween and Span) and cholesterol were formulated, and their turbidity and particle size assayed. The most appropriate niosomes formulation was mixed with novel synthesized spermine-based cationic lipids to prepare cationic niosomes that could act as gene carriers. Factors affecting gene transfection and cell viability including differences in the acyl chain length (C14, C16 and C18) of cationic lipids and the weight ratio of niosomes to DNA were evaluated on a human cervical carcinoma cell line (HeLa cells) using pDNA encoding green fluorescent protein (pEGFP-C2). The morphology, size and charge of the niosomes were also characterized, and a gel retardation assay to determine complex formation was performed. The results revealed that the transfection efficiency of the Span 20-niosomes was the highest for the spermine-C14 formulation and decreased as follows: spermine-C14 > spermine-C16 > spermine-C18. In addition to the highest transfection efficiency, there was also no serum effect on transfection efficiency of the spermine-C14 niosomes at a weight ratio of 10. This formulation was safe in vitro and had good physical stability for at least 1 month at 4°C. In conclusion, the cationic niosomes may constitute a good alternative carrier for gene transfection.