Non-viral transfection systems based on the complexes of DNA and polycations (‘polyplexes’) were evaluated with respect to their effectiveness, toxicity and cell type dependence in a variety of in vitro models. The panel of polycations examined included branched and linear polyethyleneimines, poly[N-ethyl-4-vinyl pyridinium bromide], polyamidoamine dendrimer (Superfect™), poly(propyleneimine) dendrimer (Astramol™) and a conjugate of Pluronic® P123 and polyethyleneimine (P123-g-PEI(2K)), having a graft-block copolymer architecture. Using a panel of cell lines the linear polyethyleneimine ExGen™ 500, Superfect™, branched polyethyleneimine 25 kDa, and P123-g-PEI(2K) were determined as systems displaying highest transfection activity while exhibiting relatively low cytotoxicity. These systems had activity higher than or comparable to lipid transfection reagents (Lipofectin®, LipofectAMINE™, CeLLFECTIN® and DMRIE-C) but did not reveal serum dependence and were less toxic than the lipids. Overall, this study demonstrates good potential of structurally diverse polyplex systems as transfection reagents with relatively low cytotoxicity
