Novel supramolecular gelation route to in situ entrapment and sustained delivery of plasmid DNA

In this work, cationic block copolymer (F-68-PLL) composed of Pluronic F-68 and poly(L-lysine) segments was first prepared for the binding with plasmid DNA due to the electrostatic interaction between poly(L-lysine) segments and plasmid DNA, and subsequently used to interact with α-cyclodextrin (α-CD) in aqueous system for the supramolecular gelation by the inclusion complexation between Pluronic F-68 segments and α-CD. It was found that such a fabrication process could lead to the in situ entrapment of plasmid DNA into the supramolecular hydrogel matrix under mild conditions. Depending on the amounts of F-68-PLL and α-CD, the resultant hybrid hydrogel was found to have adjustable gelation time and mechanical strength. For the plasmid DNA complexes released from the supramolecular hydrogel, controlled release and sustained gene transfection were confirmed.