| The chemical and physical properties of the surfaces/interfaces play central roles in the materials application for high technology. However, lack of simple, gentle, efficient and environment-friendly versatile strategies for surface/interface functionalization are restricting the development of advanced materials. This thesis developed a versatile platform for modification of material surfaces which was inspired by the interface adhesion of the amyloid protein assemblies in native. The platform offered easy applicability to be an extremely versatile strategy for diverse functional uses including bottom-up, top-down micro/nano-fabrication, and giant unilamellar vesicles(GUVs) capture/release.The research online is as follows:(1) Bio-inspired modification of materials interface based on the hierarchical assembly of lysozyme by phase transitionWe report the one-step aqueous coating of virtually arbitrary material surfaces using self-assembled macroscopic bionanofilm made by pure lysozyme. Governed by minimization of interfacial free energy, the unfolding and subsequent phase transition of commercially available lysozyme initiates the spontaneous formation of 2D amyloid-like nanofilm at a vapor/liquid or liquid/solid interface with a macro-scale size (e.g.20 inches in diagonal) and shape in a few minutes. The attachment of the nanofilm onto various surfaces could be accordingly achieved by the amyloid-mediated adhesion, and the robust adhesion stability supports the nanofilm to safely pass the adhesive tape peeling test. The nanofilm coating displays competitive advantages over existing alternatives including controlled thickness from nano to micro-scale, colorless and optical transparency, stable bonding strength, ordered internal and surface morphology, as well as thermal/chemical stability.(2) Top-down and bottom-up micro/nano-fabrcation mediated by two-dimensional lysozyme self-assembled nanofilmMultifunctions on the nanofilm coating have been demonstrated through great implications in both top-down and bottom-up micro/nano-scale interfacial engineering including surface modification, all-water-based photo/electron beam-lithography and electroless deposition(ELD). This finding deciphers an unbeknown interfacial assembly function for proteins that is useful to achieve a 2D biological material with the properties being useful in practical implications.(3) The surface functionalization by lysozyme phase trasition product and the application for cell-sized vesicles capture/releaseBased on a concept of a smooth and steady landing of fragile objects without destruction via a soft cushion, we have developed a model for the soft landing of deformable lipid giant unilamellar vesicles (GUVs) on functional surfaces modificated by biomacromolecule. The foundation for a successful soft landing is a solid substrate with a two-layer coating including a bottom layer of positively charged lysozymes and an upper lipid membrane layer. We came to the clear conclusion that when anionic GUVs sedimented on a surface, the vesicle rupture occurred upon direct contact with the positively charged lysozyme layer due to strong Coulombic interactions. In contrast, certain separating distances achieved by the insertion of a soft lipid membrane cushion between the charged GUVs and the lysozyme layer attenuated the Coulombic force and created a mild buffer zone, ensuring the robust capture of GUVs on the substrate without their rupture. The non-covalent bonding facilitated a fully reversible stimuli-responsive capture/release of GUVs from the biomimetic solid surface, which has never before been demonstrated due to the extreme fragility of GUVs. As a matter of fact, the controllable capture/release of cells has been proven to be of vital importance in biotechnology, and the similarity of the present approach to cell capture/release is expected to open previously inaccessible avenues of research. |
