Supramolecular Organic Frameworks as Porous Supramolecular Polymers for Bioapplications

Water-soluble supramolecular organic frameworks represent a family of supramolecular polymers that possess regular nano-scaled porosity. Three-dimensional supramolecular organic frameworks have been constructed in water from pyridinium- and imidazolium-derived tetratopic components and cucurbit[8]uril (CB[8]) by hydrophobically driven encapsulation of CB[8] for intermolecular dimers formed by peripheral aromatic subunits of the tetratopic monomers. Depending on the concentrations of the components, supramolecular organic frameworks possess dynamic diameters ranging from 20–150 nm, whereas their regular apertures can be controlled from 2.1–3.6 nm. Supramolecular organic frameworks as a whole are polycationic, but their interiors are highly hydrophobic. As nano-scaled porous supramolecular polymers, these water-soluble regular frameworks can adsorb drugs to achieve intracellular delivery and suppress the toxicity of the adsorbed drugs by reducing their concentrations and/or accumulation in the body. This chapter summarizes their construction and diverse biofunctions.