Chemical and Biomolecular Engineering - Theses

Permanent URI for this collection

http://hdl.handle.net/11343/354

Filters

2023 1
1
Reset filters

Settings
Statistics
Citations
Start date: 2020 × End date: 2023 × Subject: Biomaterials × Author: Xu, Wanjun ×

Search Results

Now showing 1 - 1 of 1
  • Item
    No Preview Available
    Molecular Insights into Nanoengineered Metal–Phenolic Networks
    Xu, Wanjun ( 2023-06)
    Coordination assembly has garnered significant attention in designing advanced materials with well-defined geometry and functions for diverse applications across various fields. Metal–phenolic networks (MPNs) are supramolecular coordination network materials composed of metal ions and natural phenolic ligands. The distinctive combination of hybrid physicochemical properties and versatile coating ability have endowed MPNs with widespread potential in biomedical, environmental, and agricultural applications. However, despite recent advancements, regulating coordination chemistry in MPNs through different coordination modes remains largely unexplored and a challenge. A comprehensive understanding of this aspect and the associated knowledge is expected to significantly boost the development of MPNs with unique morphologies and properties for a wide range of fields. This thesis aims to expand the realm of MPNs by engineering their coordination modes and kinetic at the nanoscale, thereby imparting materials with controllable properties or emerging functions for various targeting applications. Firstly, the dynamic and selective coordination modes of MPNs were experimentally and computationally investigated using flavonoids with monotopic, ditopic, and multitopic chelating sites. The dominating coordination modes in MPNs could be adjusted from metal–catechol to metal–maltol by simply changing the assembly pH, leading to distinct crosslinked coordination networks and tunable physiochemical properties (e.g., selective permeability and pH-dependent degradability) for desired applications. Secondly, flexible MPNs featuring guest-responsive behavior were achieved by introducing intermolecular competitive coordination between MPNs and external guest molecules (e.g., glucose). Upon exposure to glucose molecules, glucose partially replaced flavonoids in MPNs due to the comparable intermolecular coordination of metal ions to flavonoid ligands and glucose. This led to the re-conformation of metal-organic networks and changes in their physiochemical properties, as demonstrated experimentally and computationally. The resulting cargo-loaded MPNs could be responsive to external guest stimuli, showcasing promising potential in smart drug delivery. Thirdly, a library of MPN nanoparticles with different compositions was fabricated by controlling the coordination kinetics of metal-phenolic complexes. The formation kinetics and physiochemical properties of MPN nanoparticles were systematically controlled by employing various strategies, including adjusting the incubation time, precursor types and concentrations, and the assembly pH. Moreover, various functional components (e.g., enzyme and drug) were incorporated with MPN to fabricate functional nanoparticles for desired biomedical applications, including cell targeting and drug delivery. These studies expand the understanding of the coordination chemistry of MPNs and provide a guideline for the rational design of metal-organic materials for broader applications.