In order to investigate the effect of PEO-PPO-PEO copolymers on the glutathione (GSH)/glutathione-S-transferase (GST) detoxification system, interaction between the copolymers and GSH is studied by NMR measurements. Selective rotating-frame nuclear Overhauser effect (ROE) experiment confirms that glutamyl (Glu) α-H of GSH has spatial contact with EO methylene protons. Spin-lattice relaxation times of GSH Glu α-H show a decrease when PEO-PPO-PEO copolymers are added, and the decrease is greater with copolymers possessing more EO units. Other protons of GSH show little change in the presence of the copolymers. The addition of GSH promotes the dehydration of PEO-PPO-PEO copolymers. This results from the breaking of hydrogen bonds between water and the polymers and the forming of hydrogen bonds between Glu α-carboxylate protons and oxygen atoms of EO units. The dissociation constant between GSH and P85 copolymer is determined by spin-lattice relaxation measurements, which shows the binding is of low affinity and the two molecules are in fast dissociation kinetics. This study suggests that GSH transporting or utilizing systems may be affected by treatment of PEO-PPO-PEO copolymers.
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http://dx.doi.org/10.1021/jp111418z | DOI Listing |
Carbohydr Polym
March 2025
Bristol Composites Institute, School of Civil, Aerospace, and Design Engineering, University of Bristol, University Walk, Bristol BS8 1TR, UK. Electronic address:
Cellulose nanocrystals (CNCs) have emerged as promising, sustainable materials, with applications in sensors, coatings, pharmaceuticals, and composites. Their modification with block copolymers such as PEO-PPO-PEO triblock copolymers of the Pluronic family has been attempted many times in the literature, with claims that such modification would happen by an anchor(PEO)-buoy(PPO)-anchor(PEO) mechanism. However, there is much disagreement in the literature on this.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
Institute of Polymers, Bulgarian Academy of Sciences, "Akad. G. Bonchev" St., Bl. 103-A, 1113 Sofia, Bulgaria.
We introduce a novel concept in nucleic acid delivery based on the use of mixed polymeric micelles (MPMs) as platforms for the preparation of micelleplexes with DNA. MPMs were prepared by the co-assembly of a cationic copolymer, poly(1-(4-methylpiperazin-1-yl)-propenone)-b-poly(d,l-lactide), and nonionic poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) block copolymers. We hypothesize that by introducing nonionic entities incorporated into the mixed co-assembled structures, the mode and strength of DNA binding and DNA accessibility and release could be modulated.
View Article and Find Full Text PDFMol Pharm
November 2024
Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States.
The blood-brain barrier (BBB) is a highly restrictive barrier at the interface between the brain and the vascular system. Even under BBB dysfunction, it is extremely difficult to deliver therapies across the barrier, limiting the options for treatment of neurological injuries and disorders. To circumvent these challenges, there is interest in developing therapies that directly engage with the damaged BBB to restore its function.
View Article and Find Full Text PDFJ Phys Chem B
June 2024
Department of Chemistry, Veer Narmad South Gujarat University (VNSGU), Udhana-Magdalla Road, Surat 395 007, Gujarat, India.
This study investigates the nanoscale self-assembly from mixtures of two symmetrical poly(ethylene oxide)-poly(propylene oxide)-pol(ethylene oxide) (PEO-PPO-PEO) block copolymers (BCPs) with different lengths of PEO blocks and similar PPO blocks. The blended BCPs (commercially known as Pluronic F88 and L81, with 80 and 10% PEO, respectively) exhibited rich phase behavior in an aqueous solution. The relative viscosity (η) indicated significant variations in the flow behavior, ranging from fluidic to viscous, thereby suggesting a possible micellar growth or morphological transition.
View Article and Find Full Text PDFEnviron Res
July 2024
Electrochemical Sciences Research Chair (ESRC), Chemistry Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia. Electronic address:
The mesoporous metal oxide semiconductors exhibit unique chemical and physical characteristics, making them highly desirable for catalysis, electrochemistry, energy conversion, and energy storage applications. Here, we report the facial fabrication of mesoporous gray SnO (MGS) electrocatalysts employing an evaporation-induced co-assembly (EICA) approach, utilizing poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymers Pluronic P123 (PEO-PPO-PEO) triblock copolymer as a template for electrochemical CO reduction reaction (eCORR). By sustaining the co-assembly conditions and utilizing a thermal treatment technique based on carbon, gray mesoporous SnO materials with a high density of active sites and oxygen vacancies can be constructed.
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