The solubilization of styrene by poly(butyl methacrylate-g-methoxypoly(ethylene glycol)) and poly(methyl methacrylate-g-methoxypoly(ethylene glycol)) graft copolymers has been examined. From turbidity measurements the solubility limit of the monomer in the micelles was obtained and the distribution coefficients were evaluated. Dynamic light scattering revealed that below the solubility limit, solubilization leads to a slight increase in micelle size, while above the solubility limit, there is a dramatic increase in particle size and turbidity as oil-in-water emulsions are formed through coalescence of monomer-swollen micelles. Polymerizations carried out below the solubility limit using the graft copolymer micelles as templates resembled microemulsion polymerizations in nature and led to very fine sterically stabilized polystyrene latex particles. Through careful control of the monomer concentration and the polymerization temperature it was possible to obtain spherical nanosize latex particles with similar size to those of the micelle precursors (10 nm) up to 11% monomer by weight. Polymerizations above the solubility limit, on the other hand, showed similarities with emulsion polymerizations and resulted in larger particles with higher polydispersity.
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http://dx.doi.org/10.1016/S0021-9797(03)00240-6 | DOI Listing |
Naunyn Schmiedebergs Arch Pharmacol
January 2025
Meisterbio Co., Ltd., Okayama, Japan.
Natural stilbene compounds, such as resveratrol and pterostilbene, have been focused on owing to their diverse biological activities associated with antioxidant, anti-inflammatory, and anti-aging properties. However, their low water solubility limits their advanced applications. In this study, we investigated the protective effects of selected stilbene compounds (resveratrol, oxyresveratrol, gnetol, piceatannol, and pterostilbene) and their water-soluble derivatives (piceid, resveratrol polysaccharide, pterostilbene trisaccharide, and pterostilbene polysaccharide) against UVA-, UVB irradiation, tertiary-butyl hydroperoxide (t-BuOOH)- and hydrogen peroxide (HO)-induced injury in human epidermal cells.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
New York University Grossman School of Medicine, New York, NY, USA.
Background: Synucleinopathies lack cures. Antibody therapies targeting α-synuclein aim to inhibit aggregation and enhance degradation, but have limited brain entry because of size (150kDa). Smaller single-domain antibodies (sdAbs, 15kDa) have substantially improved brain uptake.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
German Center for Neurodegenerative Diseases (DZNE), Munich, Bavaria, Germany.
Background: Progranulin (PGRN) haploinsufficiency is a major risk factor for frontotemporal lobar degeneration with TDP-43 pathology (FTLD-GRN). Multiple therapeutic strategies are in clinical development to restore PGRN levels in the CNS, including gene therapy. However, a limitation of current gene therapy approaches aimed to alleviate FTLD-associated pathologies may be their inefficient brain exposure and biodistribution.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
TauC3 Biologics Limited, London, United Kingdom.
Background: Tau abnormalities are a central feature of Alzheimer's disease (AD) and the defining feature of non-AD tauopathies, which include frontotemporal lobar degeneration (FTLD) due to Pick's disease (PiD) or Mapt mutations (FTLD-tau), as well as progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and others. Mapt transcripts undergo alternative splicing to produce 6 distinct isoforms. Exon 2 splicing produces 0, 1 or 2 inserts; exclusion or inclusion of exon 10 results in 3-repeat (3R) or 4-repeat (4R) forms, respectively.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
The University of British Columbia, Vancouver, BC, Canada.
Background: An imbalance between the production and clearance of amyloid beta (Aß) has emerged as a major cause of sporadic Alzheimer's disease (AD). Retinal wholemount studies can identify cell-specific involvement in Aß clearance mechanisms which cannot be accomplished in the brain ex vivo.
Methods: Eye cross-sections of double transgenic (Tg, APP-PS1) and non-carrier sibling female mice (n = 16, 4 per group) at 3- and 9- month ages were probed with antibodies 6E10 (Aβ1-16 amino-acid residues, soluble and insoluble species), ionized calcium-binding adapter molecule 1 (IBA1, microglia/macrophage), glial fibrillary acidic protein (GFAP, astrocytes), glutamine synthetase (GS, Müller cells) and aquaporin-4 (AQP4, membrane water channel) using immunofluorescence.
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