Engineering Active Materials by Dissipative and Programmable Host-Guest Supramolecular Motifs

Dynamic and dissipative supramolecular systems inspired by natural processes offer exciting opportunities to develop active materials with precise temporal and spatial control. This dissertation investigates transient hydrogels and programmable nanostructures based on cucurbit[7]uril (CB[7]) host–guest interactions, utilizing both chemically fueled and enzyme-driven mechanisms. Chemically fueled dissipative hydrogels were first developed using dimethyl sulfate (DMS) as a reactive chemical fuel. These systems demonstrated tunable properties, including stiffness and lifetime, regulated by fuel concentration and environmental pH. Although these systems highlight the potential for time-controlled material dynamics, challenges such as fuel toxicity remain significant. To address these limitations, enzyme-driven systems were then explored, leveraging urease-catalyzed pH-feedback reactions to achieve biocompatible transient hydrogels. These systems exhibited faster transitions and programmability, offering a sustainable and safer alternative for biomedical applications like drug delivery and tissue scaffolding. Additionally, programmable morphological transitions were achieved in peptide amphiphile-based nanostructures, enabling reversible transformations between fibers, micelles, and aggregates. These transitions were driven by pH changes and the tunable host–guest binding affinity, demonstrating potential in nanomedicine and responsive materials. By integrating insights from hydrogels and nanostructures, the research in this dissertation provides a unified platform for designing active materials. This research lays the foundation for advancing supramolecular systems, offering innovative solutions for biomimicry materials, drug delivery systems, and beyond. The findings underscore the transformative potential of transient and programmable materials in bridging nature-inspired adaptability with synthetic innovation.