文摘
A facile, one-step synthesis of cationic block copolymers of poly(2-N-(dimethylaminoethyl) methacrylate)(pDMAEMA) and copolymers of poly(propylene oxide) (PPO) and poly(ethylene oxide) (PEO) has beendeveloped. The PEO-PPO-PEO-pDMAEMA (L92-pDMAEMA) and PEO-pDMAEMA copolymerswere obtained via free radical polymerization of DMAEMA initiated by polyether radicals generatedby cerium(IV). Over 95% of the copolymer fraction was of molecular mass ranging from 6.9 to 7.1 kDain size, indicating the prevalence of the polyether-monoradical initiation mechanism. The L92-pDMAEMA copolymers possess parent surfactant-like surface activity. In contrast, the PEO-pDMAEMA copolymers lack significant surface activity. Both copolymers can complex with DNA.Hydrodynamic radii of the complexes of the L92-pDMAEMA and PEO-pDMAEMA with plasmidDNA ranged in size from 60 to 400 nm, depending on the copolymer/DNA ratio. Addition of PluronicP123 to the L92-pDMAEMA complexes with DNA masked charges and decreased the tendency ofthe complex to aggregate, even at stoichiometric polycation/DNA ratios. The transfection efficiency ofthe L92-pDMAEMA copolymer was by far greater than that of the PEO-pDMAEMA copolymer. Anextra added Pluronic P123 further increased the transfecton efficacy of L92-pDMAEMA, but did notaffect that of PEO-pDMAEMA.