Nucleic acids (such as DNA or RNA) have great potential as therapeutic agents, but they are very fragile and degrade easily within the body. It is therefore necessary to develop delivery systems capable of protecting them and transporting them safely to the target cells.
To better control when and where these systems act, light-sensitive strategies have been developed. Some of these incorporate molecular ‘switches’ that respond to light, allowing the release of genetic material to be precisely triggered. This thesis utilises azobenzene, a molecule capable of reversibly changing its shape when irradiated with different wavelengths of light.
This thesis explores the use of light to control these systems. Three DNA vector systems have been developed that undergo light-induced structural changes, altering their organisation and function in vitro and in biological models. Two of these systems are based on a molecular strategy, in which the vector itself incorporates the azobenzene switch. The third utilises a supramolecular strategy based on host–guest recognition between cyclodextrin and azobenzene, enabling the assembly and disassembly of the system to be controlled by light.