Effects of polyrotaxane structure on polyion complexation with DNA

Aminoethylcarbamoyl-polyrotaxanes (AEC-α/E35-TYR-Zs) were synthesized as a novel cationic polymer for DNA complexation and characterized in terms of physicochemical properties of polyion complex. Here, AEC groups were introduced to hydroxyl groups of α-cyclodextrins (α-CDs) that are threaded onto a poly(ethylene glycol) (PEG) chain capped with bulky end-groups (polyrotaxane). We examined the ability of DNA complexation of the AEC-α/E35-TYR-Zs compared with polyethylenimine (PEI). Agarose gel shift assay and ethydium bromide (EB) displacement analysis showed that the number of threading α-CDs was one of the dominant factors to enhance the ability of DNA complexation. In addition, increasing the number of AEC groups in the AEC-α/E35-TYR-Zs led to tighter complexation.