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.

受自然过程启发的动态耗散超分子系统，为开发具有精准时空调控能力的活性材料提供了令人振奋的机遇。本论文以葫芦[7]脲（CB[7]）主客体相互作用为基础，利用化学燃料驱动和酶驱动两种机制，研究了瞬态水凝胶和可编程纳米结构。

首先以硫酸二甲酯（DMS）为反应性化学燃料，开发了化学燃料驱动的耗散水凝胶。这些系统表现出可调谐特性，包括刚度和寿命，其受燃料浓度和环境pH值调控。尽管这些系统凸显了时间可控材料动力学的潜力，但燃料毒性等挑战依然显著。

为解决这些局限性，随后探索了酶驱动系统，利用脲酶催化的pH反馈反应实现了生物相容性瞬态水凝胶。这些系统表现出更快的转变速度和可编程性，为药物递送和组织支架等生物医学应用提供了可持续且更安全的替代方案。

此外，在基于肽两亲性分子的纳米结构中实现了可编程形态转变，可在纤维、胶束和聚集体之间进行可逆转换。这些转变由pH变化和可调谐主客体结合亲和力驱动，在纳米医学和响应性材料领域展现出潜力。

通过整合水凝胶和纳米结构领域的见解，本论文的研究为活性材料设计提供了一个统一平台。该研究为推进超分子系统奠定了基础，为仿生材料、药物递送系统等领域提供了创新解决方案。研究结果凸显了瞬态和可编程材料在连接自然启发的适应性与合成创新方面的变革性潜力。