Cationic supramolecules composed of multiple oligoethylenimine-grafted β-cyclodextrins threaded on a polymer chain for efficient gene delivery

Abstract

A smart material design of cationic supramolecular polyrotaxane entities for efficient gene delivery was investigated. Oligoethylenimine-grafted β-CD was selected as the building block because β-CD is larger than Α-CD and can accommodate grafting. For blocking the ends of the copolymers to prevent the dethreading of β-CD a bifunctional end group was designed. To assure that there was no intra- or intermolecular crosslinking a large excess of OEI was used in the grafting reactions. The ability of the cationic polyrotaxanes to condense plasmid DNA (pDNA) into particular structures was confirmed by agarose gel electrophoresis. The4 transfection efficiency of cationic-polyrotaxane-DNA complexes was assessed using luciferase as marker gene. It was observed that the use of dimethylaminoethyl-modified Α-CD threaded onto a PEO chain and capped by cleavable end groups and the system has a lot of flapping OEI chains with many primary and secondary amines.