Disulfide‐Containing Hyperbranched Polyethylenimine Derivatives via Click Chemistry for Nonviral Gene Delivery

Reducible disulfide‐containing hyperbranched PEI‐SS‐HP was synthesized via click chemistry and evaluated as nonviral gene carrier. The structure of the polymers was confirmed by 1 H NMR and FTIR. It was shown that the PEI‐SS‐HP was able to bind plasmid DNA to positively charged nanoparticles. The reduction sensitivity of the PEI‐SS‐HP was confirmed by gel retardation assay in the presence of DTT mimicking an intracellular reductive environment. In vitro experiments revealed that the reducible PEI‐SS‐HP not only had much lower cytotoxicity, but also posed superior transfection activity as compared to non‐degradable 25‐kDa PEI. The results indicate that a reducibly degradable PEI‐SS‐HP can be a promising gene vector. magnified image