Cucurbit[8]uril ternary complexes for biomolecular assemblies in solution and at interfaces

Abstract

Self-assembly allows for rationally designed molecular platforms that exploit specific, directional, tunable and reversible non-covalent interactions. The dynamic nature of such supramolecular interactions gives rise to self-assembled systems that can sense and respond to physiological cues, or that mimic the structural and functional aspects of biological signaling. In this thesis we discuss the properties of a family of macrocycles called cucurbit[n]urils (CB[8]), with strong emphasis on the 8-membered macrocycle (CB[8]). The special characteristic of the CB[8] host is the ability of forming reversible ternary inclusion complexes with two guest molecules. The binding of CB[8] with to guests to for a ternary complex had been studied in solution in detail and this complexation unequivocally occurred non-cooperatively. Peptides and small aromatic guests can promote the formation of ternary complexes within the cavity of CB[8] displaying structural and targeting functionalities. In this thesis various applications of this type of ternary complexes have been described where amphiphilic ternary complexes have been used to form supramolecular nanoparticles with targeting and imaging ligands, where photosensitive and cell adhesive ternary complexes on self-assembled monolayers have been used to modulate the adhesion of cells and where ternary complexes have been established on supported lipid bilayers to trap non-adhesive cells carrying metabolically introduced guest moieties. We envision that the results described in this thesis will further contribute to the development of bioanalytical platforms and biomedical materials in which the self-assembly of biomolecules is driven by CB[8]-mediated interactions. Describing and studying the scope and limitations of these interactions under conditions that are relevant for this type of applications is of crucial importance.