Bridging beta-Cyclodextrin prevents self-inclusion and allows formation of supramolecular polymers: self-assembly and cooperative interaction with nucleic acids.

To imitate Nature's ability to form cooperative self-assemblies using entirely artificial molecular tools and to confer them with properties is still a true challenge. Here we show that cyclodextrins bridged with an ammonium linker which bears a hydrophobic substituent efficiently form supramolecular polymers at millimolar concentrations, avoiding the competing self-inclusion and head-to-head processes. Notably, such assembly can occur at micromolecular concentrations in the presence of genomic DNA, resulting in efficient DNA compaction that is reversible upon addition of a competitive guest, and demonstrating their highly cooperative interaction. We finally show that the supramolecular polymer also cooperatively interacts with siRNA and allows its transfection.