Chemical and Biomolecular Engineering - Theses

Permanent URI for this collection

Search Results

Now showing 1 - 2 of 2
  • Item
    Thumbnail Image
    Application of Advanced Fluorescence Imaging Techniques for Intracellular Tracking of Nano-biomaterials
    Radziwon, Agata ( 2021)
    The engineering and intracellular delivery of nanoparticles with tailored structural, functional and therapeutic properties is challenging due to the interactions of nanomaterials with complex and dynamic biological systems. Additionally, the clinical translation of nanoparticle-based chemotherapeutics is hampered by the poor capacity of 2D cell monolayer culture to mimic in vivo tumour microenvironment and cell-cell interactions. To overcome these biological barriers and enable the clinical translation of nanoparticles, a thorough investigation of nanoparticle-cell interactions in complex biological environments is of paramount importance. For this purpose, novel advanced fluorescence techniques enable the study of nanoparticles structure and functional properties inside the cells with improved spatial and temporal resolution. Additionally, the development of complex 3D cell culture systems mimicking tumour tissue could provide a novel method to predict the in vivo behaviour of nanoparticle-based chemotherapeutics and cellular response to the treatment. Herein DNA- and sugar-based nanoparticles have been developed as platforms for the detection of molecular targets and delivery of drugs within cells and in complex biological settings. Specifically, fluorescence resonance energy transfer microscopy, fluorescence correlation spectroscopy, fluorescence lifetime imaging microscopy and multicolour single-molecule localization microscopy were employed to probe the specific binding of the DNA nanosensor to the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and the nanocomplexation of glycogen with albumin. The intracellular trafficking and the activity of drug-loaded nanoparticles were investigated in 2D and 3D static and dynamic cell culture systems. The biological activity of glycogen-albumin nanoparticles was investigated in a 3D tumour microtissue obtained by co-culturing BT474, NIH-3T3 and RAW264.7 cells in a U-Cup perfusion bioreactor device. The interactions of glycogen-albumin nanoparticles with peripheral blood mononuclear cells isolated from human blood and nanoparticles in vivo biodistribution in mice were also analyzed. This study aims to gain an understanding of the bio-nano interactions in various biological systems and highlights the importance of combining multiple fluorescence techniques and complex models for monitoring the intracellular behaviour of nanomaterials and accurately predicting their in vivo behaviour.
  • Item
    Thumbnail Image
    Functional Supramolecular Network Engineering Inspired by Metal–Phenolic Complexation
    Chen, Jingqu Rachel ( 2021)
    Supramolecular assembly provides a versatile pathway for engineering bespoke materials, such as metal–organic hybrid materials. Metal–phenolic networks (MPNs), constructed from the coordination-driven assembly of phenolic ligands and metal ions, are an emerging class of hybrid materials with a rich choice of building blocks. Due to their strong adhesion to different substrates (particles, planar surfaces, microorganisms), high degree of modularity, and tuneable degradability, MPNs have garnered considerable attention in fields such as drug delivery, bioimaging, antimicrobials, separation, and catalysis. However, fundamental research in the material aspects of MPNs and how these influence biomedical applications are essential yet overlooked. This thesis explores the fundamental principles of MPNs and uses this insight to examine MPN materials in a range of biomedical applications. First, MPN microcapsules comprised of various building blocks are engineered, and their programmable gating mechanisms are explored in terms of intermolecular dynamics. This fundamental study not only provides insight into the dynamic nature of MPNs but also offers a route to engineer smart delivery systems and selective gating materials. Next, MPN coatings are used as a versatile and cytocompatible platform to trigger the endosomal escape of nanoparticles, which has been regarded as a key bottleneck for the intracellular delivery of therapeutics. The escape mechanism is systematically investigated and determined to be the “proton-sponge effect”, arising from the buffering capacity of MPNs. Notably, this buffering-enabled escape capability is preserved after the post-functionalization of MPN coatings with polymers, showing the generalizable nature of the platform. Therefore, a subsequent in-depth exploration of the buffering effects of MPNs sheds mechanistic insight into metal–organic systems and their emergent buffering capacity based on coordination dynamics and building block choice. Finally, the advantages of different polyphenol-enabled supramolecular networks are integrated to expand the MPN platform from thin films to self-assembled nanoparticles. Bioactive metal–phenolic nanoparticles are developed via robust and template-free assembly. Hydrophobic interactions and coordination play dominant roles in the assembly and stabilization of the nanoparticles. Furthermore, the incorporation of diverse biomacromolecules (e.g., functional proteins and genes) during assembly enables the potential use of these metal–phenolic nanoparticles in various biomedical applications, anticancer treatments, cascade reactions, and gene knockdown.