This thesis describes the design and characterisation of hydrogels based on the host-guest chemistry of cucurbit[8]uril for the controlled delivery of molecular cargo. The host molecule is capable of binding two guest molecules in an inclusion complex. Its addition to an aqueous solution of guest-functional polymers leads to the formation of cross-links and hydrogels.

The first results chapter of this thesis explores the relationship between cross-link dynamics and molecular cargo delivery. The release rate increases with increasing rate of dissociation and decreasing activation energy of dissociation. Therefore, the rate of molecular cargo release can be fine-tuned by choosing guests with different dissociative kinetic and thermodynamic binding parameters.

Subsequent results chapters report the preparation and application of hydrogels using a coumarin derivative as guest. The effect of the degree of guest functionalisation, concentration of the polymer, molecular weight of the polymer, and concentration of the host molecule on mechanical properties is investigated. Furthermore, coumarin is a light-sensitive molecule. Physical hydrogels are remotely and irreversibly converted into stiffer covalently cross-linked polymer networks upon irradiation with light. Finally, the rate of molecular cargo release from these hydrogels increases with decreasing length of irradiation time, degree of guest functionalisation, concentration of the polymer, or molecular weight of the polymer.