The physical chemical properties of block substituted poly(ethylene oxide-propylene oxide) (PEO-PPO) block copolymer aqueous solutions were evaluated in the presence of two hydrotropes of different structures: sodium p-toluene sulfonate (NaPTS) and butyl monoglycol sodium sulfonate (NaBMGS). The critical micelle concentration and the cloud point of the copolymer solutions were displaced to higher concentration values, indicating that the solubility of the copolymer was increased in the presence of the hydrotropes. Temperature increased the micelle hydrodynamic radius, but concentration had a limited effect. Carbon-13 nuclear magnetic resonance (13C NMR) permitted the interaction between the surface-active agent and the hydrotrope to be evaluated: NaBMGS, which presented a more pronounced hydrotropic effect, interacts more effectively with the hydrophobic moiety of the surfactant, while NaPTS interacts rather mainly with the hydrophilic oxyethylenic groups. The results furnish experimental evidence to conclude that the hydrotropic phenomenon is specific in relation to both the hydrotrope and the solubilizate.
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http://dx.doi.org/10.1021/la048167j | DOI Listing |
J Mater Chem B
January 2025
Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Department of Ophthalmology, Reina Sofia University Hospital and University of Cordoba, 14004 Cordoba, Spain.
Gold nanoparticles (AuNPs) play a key role in the field of nanomedicine due to their fascinating plasmonic properties as well as their great biocompatibility. An intriguing application is the use of plasmonic photothermal therapy (PPTT) mediated by anisotropic AuNPs irradiated with a near-infrared (NIR) laser for treating ocular diseases in ophthalmology. For this purpose, bipyramidal-shaped AuNPs (BipyAu), which were surface-functionalized with three different organic ligands (citrate, polystyrene sulphonate (PSS), and cetyltrimethylammonium bromide (CTAB)), were synthesized.
View Article and Find Full Text PDFCurr Pharm Des
January 2025
Department of Pharmaceutics, College of Pharmacy, Shaqra University, Shaqra 11961, Kingdom of Saudi Arabia.
Nanogels (NGs) are presently the focus of extensive research because of their special qualities, including minimal particle size, excellent encapsulating efficacy, and minimizing the breakdown of active compounds. As a result, NGs are great candidates for drug delivery systems. Cross-linked nanoparticles (NPs) called stimulus-responsive NGs are comprised of synthetic, natural, or a combination of natural and synthetic polymers.
View Article and Find Full Text PDFJACS Au
January 2025
Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Key Laboratory of Polymer Chemistry & Physics, Beijing 100871, People's Republic of China.
Individual molecules dissolved in a dilute solution are usually considered not to correlate with each other as they undergo chemical reactions due to the mismatch of the diffusion and reaction time scales. Recent studies suggest otherwise, especially for reactions involving macromolecules. With selenopolypeptides as a model system, we used ensemble measurements and single-molecule direct imaging to investigate the correlation between physically constrained chemical reaction sites on a linear polymer chain and the coupling effects between conformation changes and reaction kinetics.
View Article and Find Full Text PDFChem Sci
January 2025
Center for Research in Biological Chemistry and Molecular Materials (CIQUS), Department of Chemical Engineering, Universidade de Santiago de Compostela Rúa de Jenaro de la Fuente, s/n 15705 Santiago de Compostela Spain
For decades, extensive surfactant libraries have been developed to meet the requirements of downstream applications. However, achieving functional diversity has traditionally demanded a vast array of chemical motifs and synthetic pathways. Herein, a new approach for surfactant design based on structural isomerism is utilised to access a wide spectrum of functionalities.
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
January 2025
Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Lodz, Poland.
Background: The 2D:4D digit ratio (DR), representing the relative length of the index finger to the ring finger, is an anthropometric marker that shows sexual dimorphism, with males typically having a lower ratio than females. This parameter is linked to prenatal androgen exposure (PAE), which influences sexual differentiation of the brain and behavior. This study aimed to investigate the correlation between PAE and sleep among young adults.
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