ORCID Profile
0000-0002-5469-5456
Current Organisation
University of British Columbia
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Publisher: American Chemical Society (ACS)
Date: 08-04-2019
DOI: 10.1021/ACSMACROLETT.9B00140
Abstract: Gels are attractive for applications in drug delivery, tissue engineering, and 3D printing. Here, physical colloidal gels were prepared by freeze-thaw (FT) cycling of cellulose nanocrystal (CNC) suspensions. The aggregation of CNCs was driven by the physical confinement of CNCs between growing ice crystal domains. FT cycling was employed to form larger aggregates of CNCs without changing the surface chemistry or ionic strength of the suspensions. Gelation of CNC suspensions by FT cycling was demonstrated in water and other polar solvents. The mechanical and structural properties of the gels were investigated using rheometry, electron microscopy, X-ray diffraction, and dynamic light scattering. We found that the rheology could be tuned by varying the freezing time, the number of FT cycles, and concentration of CNCs in suspension.
Publisher: American Chemical Society (ACS)
Date: 10-01-2018
Publisher: American Chemical Society (ACS)
Date: 12-01-2017
DOI: 10.1021/ACSCHEMNEURO.6B00433
Abstract: In Alzheimer's disease, the microtubule-associated protein tau forms intracellular neurofibrillary tangles (NFTs). A critical step in the formation of NFTs is the conversion of soluble tau into insoluble filaments. Accordingly, a current therapeutic strategy in clinical trials is aimed at preventing tau aggregation. Here, we assessed altenusin, a bioactive polyphenolic compound, for its potential to inhibit tau aggregation. Altenusin inhibits aggregation of tau protein into paired helical filaments in vitro. This was associated with stabilization of tau dimers and other oligomers into globular structures as revealed by atomic force microscopy. Moreover, altenusin reduced tau phosphorylation in cells expressing pathogenic tau, and prevented neuritic tau pathology induced by incubation of primary neurons with tau fibrils. However, treatment of tau transgenic mice did not improve neuropathology and functional deficits. Taken together, altenusin prevents tau fibrillization in vitro and induced tau pathology in neurons.
Publisher: American Chemical Society (ACS)
Date: 24-06-2019
DOI: 10.1021/ACS.BIOMAC.9B00533
Abstract: The functionalization of cellulose nanocrystal (CNC) aerogels was achieved through a two-step synthetic procedure. CNC aerogels were prepared under hydrothermal conditions, followed by solvent exchange and critical point drying. The CNC aerogels were functionalized with a methacrylate group and then underwent thiol-ene click chemistry to impart a range of functionalities onto the surface of the CNC aerogel. The use of the functionalized aerogels as oil absorbents was then investigated, with the most hydrophobic CNC aerogel, 1 H,1 H,2 H,2 H-perfluorodecanethiol-functionalized CNC aerogel, exhibiting the highest absorption of xylenes at 2.9 mL g
Publisher: American Chemical Society (ACS)
Date: 28-07-2016
DOI: 10.1021/ACS.BIOMAC.6B00906
Abstract: We report the facile preparation of gels from the hydrothermal treatment of suspensions of cellulose nanocrystals (CNCs). The properties of the hydrogels have been investigated by rheology, electron microscopy, and spectroscopy with respect to variation in the temperature, time, and CNC concentration used in preparation. Desulfation of the CNCs at high temperature appears to be responsible for the gelation of the CNCs, giving highly porous networks. The viscosity and storage modulus of the gels was shown to increase when s les were prepared at higher treatment temperature. Considering the wide natural abundance and biocompatibility of CNCs, this simple, green approach to CNC-based hydrogels is attractive for producing materials that can be used in drug delivery, insulation, and as tissue scaffolds.
Publisher: Wiley
Date: 08-04-2019
Abstract: Pressure-responsive chiral photonic aerogels are fabricated by combining liquid crystal self-assembly and ice-templating processes. The aerogels have a hierarchical structure in which the primary 2D chiral nematic structured walls of cellulose nanocrystals form ribbons that support a secondary 3D cellular network. Owing to the flexibility of the aerogels in solvent, the 3D structure of the aerogel can easily be transformed to a 2D structure by pressure-induced rearrangement. The aerogels vary from white in color, which arises from light scattering, to a reflective photonic crystal displaying bright iridescent colors that depend on the immersed solvent. A solvent-sensitive ink that shows quick color response to different solvents is designed using the pressure-responsive photonic aerogel. This material demonstrates a new response mechanism for the design of smart and mechanoresponsive photonic materials.
Publisher: Wiley
Date: 04-02-2020
Abstract: Cellulose nanocrystals (CNCs) spontaneously assemble into gels when mixed with a polyionic organic or inorganic salt. Here, we have used this ion-induced gelation strategy to create functional CNC gels with a rigid tetracationic macrocycle, cyclobis(paraquat-p-phenylene) (CBPQT
Publisher: Wiley
Date: 04-02-2020
No related grants have been discovered for Lev Lewis.