Expression profile of plasmid DNA obtained using spermine derivatives of pullulan with different molecular weights.

The objective of this study was to prepare a novel gene carrier from pullulan, a polysaccharide with an inherent affinity for the liver, and evaluate the feasibility in gene transfection. Pullulan with different molecular weights was cationized by chemical introduction of spermine. The cationized pullulan derivative was complexed with a plasmid DNA and applied to HepG2 cells for in vitro gene transfection. The level of gene expression depended on the molecular weight of cationized pullulan derivatives and the highest level was observed for the cationized pullulan derivative with a molecular weight of 47.3 x 10(3). Pre-treatment of cells with asialofetuin decreased the level of gene expression by the complexes. These findings indicate that the cationized pullulan derivative is a promising non-viral carrier of plasmid DNA which is internalized in a receptor-mediated fashion.