Surface modification with pluronic P123 enhances transfection efficiency of PAMAM dendrimer

To improve gene delivery efficiency and decrease cytotoxicity of polyamidoamine (PAMAM) polymers, P123-g-PAMAM was synthesized by modifying PAMAM with pluronic P123. The structure of the synthesized polymers was analyzed using proton nuclear magnetic resonance. The polymers were able to self-assemble with DNA, forming nanometer-scale complexes. Particle size measurement confirmed that the mean diameter of the polyplexes was 100–250 nm. The cytotoxicity and transfer efficiency were measured and compared with those of PEI and PAMAM. All of the polyplexes showed significantly low cytotoxicity in the MCF-7, HepG2, and 293T cell lines. In addition, the low level of P123 grafting to PAMAM showed significantly higher transfection efficiency than unmodified PAMAM at the optimal N/P ratio. These results suggest that P123-ylated PAMAM may prove as a useful carrier for gene delivery. [graphic not available: see fulltext]