ABSTRACT
Some representative cationic polymers, namely polyethylenimine (PEI), poly(L-lysine) (PLL), and polyamidoamine (PAMAM) dendrimer, were shown to possess cytotoxicity and form heterogeneous water-insoluble particles, leading to precipitation after complexing with DNA, and to
unsatisfactory transfection efficiency in vitro and in vivo.1-4 These polymers had been actively studied at an early stage of polymeric gene delivery research.
