Aside from its prominent role in the excretory system, urea is also a known protein denaturant. Here, we characterize urea as it behaves in confined spaces of AOT (sodium bis(2-ethylhexyl) sulfosuccinate) reverse micelles as a model of tight, confined spaces found at the subcellular level. Dynamic light scattering revealed that low temperatures (275 K) caused the smallest of the reverse micelle sizes, = 10, to destabilize and dramatically increase in apparent hydrodynamic diameter. We attribute this to urea embedded into the surfactant interface as confirmed by 2D H-NOESY NMR spectroscopy. This increase in size in turn caused the hydrogen exchange between urea and water within the nanosized reverse micelles to increase as measured by 1D EXSY-NMR. A minimal enlarging effect and no increase in hydrogen exchange were observed when aqueous urea was introduced into = 15 or 20 reverse micelles, suggesting that this effect is unique to particularly small-diameter spaces (∼7 nm).
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.langmuir.2c00206 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Dually Fluorinated Unimolecular Micelles for Stable Oxygen-Carrying and Enhanced Photosensitive Efficiency to Boost Photodynamic Therapy against Hypoxic Tumors.
Acta Biomater
January 2025
State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials; Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application; Suzhou key Laboratory of Macromolecular Deign and Precision Synthesis; College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, China. Electronic address:
Tumor hypoxia is one of key challenges in deep tumor photodynamic therapy (PDT), and how to fix this issue is attracting ongoing concerns worldwide. This work demonstrates dually fluorinated unimolecular micelles with desirable and stable oxygen-carrying capacity, high cellular penetration, and integrative type I & II PDT for deep hypoxic tumors. Dually fluorinated star copolymers with fluorinated phthalocyanines as the core are prepared through photoinitiated electron/energy transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization under irradiation with NIR LED light at room temperature, followed by assembly into unimolecular micelles.
View Article and Find Full Text PDFUpconverting/magnetic Janus-like nanoparticles integrated into spiropyran micelle-like nanocarriers for NIR light- and pH- responsive drug delivery, photothermal therapy and biomedical imaging.
Colloids Surf B Biointerfaces
January 2025
Biofunctional Nanomaterials Laboratory, Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico. Electronic address:
The integration of multiple functionalities into single theranostic platforms offers new opportunities for personalized and minimally invasive clinical interventions, positioning these materials as highly promising tools in modern medicine. Thereby, magneto-luminescent Janus-like nanoparticles (JNPs) were developed herein, and encapsulated into near-infrared (NIR) light- and pH- responsive micelle-like aggregates (Mic) for simultaneous magnetic targeting, biomedical imaging, photothermal therapy, and pH- NIR-light activated drug delivery. The JNPs consisted of NaYF:Yb,Tm upconverting nanoparticles (UCNPs) on which a well-differentiated magnetite structure (MNPs) grew epitaxially.
View Article and Find Full Text PDFThermoelectrochemical Method for Quantification of the Micellization Entropy of Redox-Active Polymers.
ACS Macro Lett
January 2025
Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Redox-active micelles undergo reversible association and dissociation in response to their redox potential and are promising materials for various applications, such as drug delivery and bioimaging. Evaluation of the micellization entropy is critical in controlling the thermodynamics of micelle formation. However, conventional methods such as isothermal titration calorimetry and surface tensiometry require a long measurement time to observe changes in the heat flow or the surface tension caused by the micellization.
View Article and Find Full Text PDFUltrafast, Robust, and Reversible Self-Assembled Nanofibers via Thiolactone Chemistry Strategy.
Small
January 2025
Xi'an Key Laboratory of Functional Organic Porous Materials, Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, 710129, P. R. China.
Self-assembly in supramolecular chemistry is crucial for nanostructure creation but faces challenges like slow speeds and lack of reversibility. In this study, a novel comb-like polymer poly(amide sulfide) (PAS) based on thiolactone chemistry is reported, which rapidly self-assemble into stable nanofibers, offering excellent robustness and reversibility in the self-assembled structure. The PAS backbone contains pairs of amide bonds, each linked to an alkyl side chain in a controlled 2:1 ratio.
View Article and Find Full Text PDFAnionic Oligo(ethylene glycol)-Based Molecular Brushes: Thermo- and pH-Responsive Properties.
Polymers (Basel)
December 2024
Research Laboratory "New Polymeric Materials", Nizhny Novgorod State Technical University, n.a. R.E. Alekseev, 24 Minin Street, 603155 Nizhny Novgorod, Nizhegorodskaya Oblast, Russia.
Anionic thermo- and pH-responsive copolymers were synthesized by photoiniferter reversible addition-fragmentation chain transfer polymerization (PI-RAFT). The thermo-responsive properties were provided by oligo(ethylene glycol)-based macromonomer units containing hydrophilic and hydrophobic moieties. The pH-responsive properties were enabled by the addition of 5-20 mol% of strong (2-acrylamido-2-methylpropanesulfonic) and weak (methacrylic) acids.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!