Supramolecular Self-Assembly of Poly(ethylene glycol)-Block-Poly (L-lysine) Dendrimer with Plasmid DNA.

Research and development related to nonviral gene carriers comprising chemically synthesized molecules has increased enormously during the past decade. Polycationic polymers and cationic lipids have constituted the main themes of the studies. Various polymers from synthetic to naturally occurring ones have been introduced and tested for their suitability in the field of gene therapy. Several cationic polymers were found to be promising but their intrinsic drawbacks, such as solubility, cytotoxicity, and low transfection efficiency, limited their use as in vivo gene carriers (1). Among them, however, dendrimers are still very attractive to many scientists for the design of gene carriers because of their well-defined structure and ease of control of surface functionality. Already, both polyamidoamine dendrimer and polyethylenimine dendrimer have been tested for their potential utility and have exhibited high transfection efficiency in vitro and in vivo (2,3). However, these dendrimers have not yet overcome the problems of solubility of the complex with DNA and cytotoxicity.