Description
- Abstract:
- How nanomaterials interact with biological systems is of fundamental interest to a wide range of applications, including drug delivery, therapeutics, bioimaging, nanotoxicity and regulation. In this thesis, we first show a unique mechanism of hexagonal boron nitride (hBN) induced cytotoxicity: a sharp hBN flake could penetrate a lipid bilayer and form a cross-membrane water channel along its exposed polar edges, leading to lysosomal membrane permeabilization (LMP), whereas a round hBN flake could not penetrate a lipid bilayer due to high energy barrier and a lack of long enough polar edges. Our in vitro studies confirm the water channel mechanism. Next, we focus on how biosurfactant molecules assist liquid-phase exfoliation (LPE) of hBN. With molecular dynamics (MD) simulations and free energy calculations (FEC), we pinpoint the driving forces and identify the underlying molecular mechanisms for two processes that assist LPE: biosurfactant deposition and self-assembly on the exfoliated surface of hBN. A general guideline is provided to the design of novel surfactant molecules for more efficient LPE of two-dimensional (2D) materials. Finally, we investigate coacervation and encapsulation of a designed peptide, WA30. Tryptophan (W) residues drive neighboring WA30 peptides together due to hydrophobic interactions, and intermolecular hydrogen bonds (H-bonds) form between the neighboring peptides stabilize the coacervate. A rapid change in the composition of solution near the coacervate might lead to peptide encapsulation. Overall, this thesis is aimed to provide some of the required theoretical insights towards understanding bio-nano-interactions, specifically, in cell-nanomaterial interactions, biosurfactant assisted liquid-phase exfoliation, as well as peptide coacervation and encapsulation.
- Notes:
- Thesis (Ph. D.)--Brown University, 2022
Citation
Qian, Xuliang,
"Mechanics and Molecular Mechanisms in Bio-Nano-Systems"
(2022).
Mechanics of Solids Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://repository.library.brown.edu/studio/item/bdr:3wvetn5p/
Relations
Collection:
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Mechanics of Solids Theses and Dissertations
Theses and Dissertations for the Mechanics of Solids department....