We describe precise supramolecules that enable the evaluation of the effective hydrophobicity of amphiphilic or "patchy" nanoglobular systems. These supramolecules exhibit the lower critical solution temperature phenomenon, which provides a quantitative measure of their effective hydrophobicity. Specifically, two isomeric 8-aryl-2'-deoxyguanosine derivatives with a transposed pair of methylene groups self-assemble into hexadecameric nanoglobular supramolecular G-quadruplexes (SGQs) that show large differences in their transition temperatures as determined by turbidity and differential scanning calorimetry studies. Molecular modeling studies suggested that differential clustering of the hydrophobic patches on the surface is responsible for the striking differences between the two isomeric supramolecules.
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http://dx.doi.org/10.1021/ja401373h | DOI Listing |
J Drug Target
November 2024
PGTD Chemistry, RTM Nagpur University, Nagpur, India.
3-D multi-faceted, nano-globular PAMAM dendritic skeleton is a highly significant polymer that offers applications in biomedical, industrial, environmental and agricultural fields. This is mainly due to its enhanced properties, including adjustable surface functionalities, biocompatibility, non-toxicity, high uniformity and reduced cytotoxicity, as well as its numerous internal cavities. This trait inspires further exploration and advancements in tailoring approaches.
View Article and Find Full Text PDFSci Total Environ
September 2023
Department of Genetics, Physiology and Microbiology, Faculty of Biology, C/. José Antonio Nováis, 12, Complutense University of Madrid, 28040 Madrid, Spain. Electronic address:
A strain of the protozoan ciliate Tetrahymena thermophila adapted to increasing Pb(II) concentrations over two years has shown that one of the resistance mechanisms to this extreme metal stress is the lead biomineralization to chloropyromorphite, one of the most stable minerals in the earth's crust. Several techniques such as microanalysis coupled to transmission and scanning electron microscopy (X-Ray Energy Disperse Spectroscopy), fluorescence microscopy and X-ray power diffraction analysis have revealed the presence of chloropyromorphite as crystalline aggregates of nano-globular structure, together with the presence of other secondary lead minerals. This is the first time that the existence of this type of biomineralization in a ciliate protozoan is described.
View Article and Find Full Text PDFMaterials (Basel)
October 2022
Center of New Chemical Technologies BIC, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, 644040 Omsk, Russia.
Porous carbon-carbon composite materials (PCCCM) were synthesized by the alkaline dehydrochlorination of polyvinyl chloride solutions in dimethyl sulfoxide containing the modifying additives of a nanostructured component (NC): graphite oxide (GO), reduced graphite oxide (RGO) or nanoglobular carbon (NGC), with subsequent two-step thermal treatment of the obtained polyvinylene-NC composites (carbonization at 400 °C and carbon dioxide activation at 900 °C). The focus of the study was on the analysis and digital processing of transmission electron microscopy images to study local areas of carbon composite materials, as well as to determine the distances between graphene layers. TEM and low-temperature nitrogen adsorption studies revealed that the structure of the synthesized PCCCM can be considered as a porous carbon matrix in which either carbon nanoglobules (in the case of NGC) or carbon particles with the "crumpled sheet" morphology (in the case of GO or RGO used as the modifying additives) are distributed.
View Article and Find Full Text PDFJ Am Chem Soc
April 2022
Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Pr. 47, Moscow 119991, Russia.
Homogeneous catalysis is typically considered "well-defined" from the standpoint of catalyst structure unambiguity. In contrast, heterogeneous nanocatalysis often falls into the realm of "poorly defined" systems. Supported catalysts are difficult to characterize due to their heterogeneity, variety of morphologies, and large size at the nanoscale.
View Article and Find Full Text PDFVaccine
March 2022
Mercia Pharma, Inc., New York, NY, USA.
Background: Increased influenza vaccine efficacy is needed in the elderly at high-risk for morbidity and mortality due to influenza infection. Adjuvants may allow hemagglutinin (HA) dose-sparing with enhanced immunogenicity. MAS-1 is an investigational water-in-oil emulsion-based adjuvant/delivery system comprised of stable nanoglobular aqueous droplets.
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