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The advancement of experimental methods has provided new information about the structure and structural fluctuations of water. Despite the appearance of numerous models, which aim to describe a wide range of thermodynamic and electrical characteristics of water, there is a deficit in systemic understanding of structuring in aqueous solutions. A particular challenge is the fact that even pure water is a heterogeneous, multicomponent system composed of molecular and supramolecular structures. The possibility of the existence of such structures and their nature are of fundamental importance for various fields of science. However, great difficulties arise in modeling relatively large supramolecular structures (e.g. extended hydration shells), where the bonds between molecules are characterized by low energy. Generally, such structures may be non-equilibrium but relatively long-lived. Evidently, the short times of water microstructure exchanges do not mean short lifetimes of macrostructures, just as the instability of individual parts does not mean the instability of the entire structure. To explain this paradox, we review the data from experimental and theoretical research. Today, only some of the experimental results on the lifetime of water structures have been confirmed by modeling, so there is not a complete theoretical picture of the structure of water yet. We propose a new hierarchical water macrostructure model to resolve the issue of the stability of water structures. In this model, the structure of water is presented as consisting of many hierarchically related levels (the stratification model). The stratification mechanism is associated with symmetry breaking at the formation of the next level, even with minimal changes in the properties of the previous level. Such a hierarchical relationship can determine the unique physico-chemical properties of water systems and, in the future, provide a complete description of them. [ABSTRACT FROM AUTHOR]

The implementation of hot melt adhesives reaching structural adhesion with both impact resistance and detachability is of prospective industry value but still remains challenging. In this work, 2‐amino‐4‐hydroxy‐6‐methylpyrimidine serving as both chain extender and end‐capping reagent due to its isomerism, was developed to construct a supramolecular polyurethane‐derived hot melt structural adhesive. The as‐synthesized PUM elastomers occurs obvious decrease of molecular weight at 80°C compared to room temperature, revealing the existence of self‐complementary 2‐ureido‐4[1H]‐pyrimidinone (UPy) motifs at chain ends. This unique structure allows to chemically incorporate abundant hierarchical and quadruple hydrogen bonding moieties, which results in remarkable enhancement of shear strength, ranging from 6.4 to 16.6 MPa. More importantly, it also exhibits unique impact‐strengthening and reproducible adhering ability. The Hopkinson‐press‐bar and cyclic tensile tests manifest that quadruple hydrogen bonds play a pivotal role in buffering external forces and increasing energy dissipation when exposed to high velocity impacts. The true stress and strain synchronously increase as the strain rate augments while the shear strength can even roar up to ~18 MPa at high tensile speed. With regard to mild synthetic conditions, atomic economic use of reactants, it is promising that this material has industrial potential to be utilized in applications referred to energy‐absorption and reproducible structural adhesion. [ABSTRACT FROM AUTHOR]

The study of bacterial immune systems has recently gained momentum, revealing a fascinating trend: many systems form large supramolecular assemblies. Here, we examine the potential mechanisms underpinning the evolutionary success of these structures, draw parallels to eukaryotic immunity, and offer fresh perspectives to stimulate future research into bacterial immunity. [ABSTRACT FROM AUTHOR]

The study of cyclic peptides (CPs) and self-assembling cyclic peptide nanotubes (SCPNs) is pivotal in advancing applications in diverse fields such as biomedicine, nanoelectronics, and catalysis. Recognizing the limitations in the experimental study of these molecules, this article introduces CYCLOPEp Builder, a comprehensive web-based application designed to facilitate the design, simulation, and visualization of CPs and SCPNs. The tool is engineered to generate molecular topologies, essential for conducting Molecular Dynamics simulations that span All-Atom to Coarse-Grain resolutions. CYCLOPEp Builder's user-friendly interface simplifies the complex process of molecular modeling, providing researchers with the ability to readily construct CPs and SCPNs. The platform is versatile, equipped with various force fields, and capable of producing structures ranging from individual CPs to complex SCPNs with different sequences, offering parallel and antiparallel orientations among them. By enhancing the capacity for detailed visualization of molecular assemblies, CYCLOPEp Builder improves the understanding of CP and SCPN molecular interactions. This tool is a step forward in democratizing access to sophisticated simulations, offering an invaluable resource to the scientific community engaged in the exploration of supramolecular structures. CYCLOPEp is accessible at http://cyclopep.com/

Liquid crystals have been extensively used in various applications, such as optoelectronic devices, biomedical applications, sensors and biosensors, and packaging, among others. Liquid crystal polymers are one type of liquid crystal material, combining their intrinsic properties with polymeric flexibility for advanced applications in displays and smart materials. For instance, liquid crystal polymers can serve as drug nanocarriers, forming cubic or hexagonal mesophases, which can be tailored for controlled drug release. Further applications of liquid crystals and liquid crystal polymers include the preparation of membranes for separation processes, such as wastewater treatment. Furthermore, these materials can be used as ion-conducting membranes for fuel cells or lithium batteries due to their broad types of mesophases. This review aims to provide an overall explanation and classification of liquid crystals and liquid crystal polymers. Furthermore, the great potential of these materials relies on their broad range of applications, which are determined by their unique properties. Moreover, this study provides the latest advances in liquid crystal polymer-based membranes and their applications, focusing especially on fuel cells. Moreover, future directions in the applications of various liquid crystals are highlighted. [ABSTRACT FROM AUTHOR]

The advancement of experimental methods has provided new information about the structure and structural fluctuations of water. Despite the appearance of numerous models, which aim to describe a wide range of thermodynamic and electrical characteristics of water, there is a deficit in systemic understanding of structuring in aqueous solutions. A particular challenge is the fact that even pure water is a heterogeneous, multicomponent system composed of molecular and supramolecular structures. The possibility of the existence of such structures and their nature are of fundamental importance for various fields of science. However, great difficulties arise in modeling relatively large supramolecular structures (e.g. extended hydration shells), where the bonds between molecules are characterized by low energy. Generally, such structures may be non-equilibrium but relatively long-lived. Evidently, the short times of water microstructure exchanges do not mean short lifetimes of macrostructures, just as the instability of individual parts does not mean the instability of the entire structure. To explain this paradox, we review the data from experimental and theoretical research. Today, only some of the experimental results on the lifetime of water structures have been confirmed by modeling, so there is not a complete theoretical picture of the structure of water yet. We propose a new hierarchical water macrostructure model to resolve the issue of the stability of water structures. In this model, the structure of water is presented as consisting of many hierarchically related levels (the stratification model). The stratification mechanism is associated with symmetry breaking at the formation of the next level, even with minimal changes in the properties of the previous level. Such a hierarchical relationship can determine the unique physico-chemical properties of water systems and, in the future, provide a complete description of them.

Three star‐like carriers with poly(hydroxy propyl methacrylate) (PHPMA) cores and poly(oligoethylene glycol methacrylate) (POEGMA) arms as nanocarriers were utilized for the encapsulation of rhodamine B, resveratrol, and curcumin. These drugs differ in hydrophobicity and therapeutic effects. The carriers had high encapsulation and loading efficiency (>95% and 10 wt%, respectively) and formed hydrogen bonds with the drugs. They were spherical in phosphate buffer saline and formed aggregates of various sizes (11–116 nm) depending on the star composition and the drug type. The carriers were stable for 2 months, but released different amounts of drugs afterwards, except for curcumin, which stayed entrapped. The curcumin‐loaded carriers also generated reactive oxygen species. These findings demonstrate the versatility of PHPMA/POEGMA stars as nanocarriers for diverse applications in nanomedicine. [ABSTRACT FROM AUTHOR]

A method is proposed for the synthesis of new supramolecular structures consisting of silver nanoparticles (NP), the surface of which is covered with spontaneously formed ordered micelle-like aggregates of cetyltrimethylammonium bromide (CTMAB) molecules. In studying the processes of the self-assembly of CTMAB molecules on the surface of silver nanoparticles and the structure of associates formed in this case, the method of fluorescent probes (molecular probe pyrene) is used. The optimal conditions for obtaining new supramolecular structures are determined. The proposed supramolecular structures can be used for the luminescence determination of various chemical compounds. At that the formation of an analytical signal will be determined by the interaction of the analyte with micelle-like aggregates located near the silver NP and will depend on both the structure of the aggregate and the polarity of the analyte. [ABSTRACT FROM AUTHOR]

The increased focus on green energy storage devices and the related rapid advancement in biomedical technologies makes the investigation of biocompatible integrated systems with medical relevance increasingly important. Peptides and their assembled morphologies with their innate biocompatibility and biodegradability are emerging as promising candidates in this respect due to their structural attributes which can be easily tuned to form supramolecular 3D architectures with extended pathways for ionic mobility. However, to comprehend their applicability in energy storage devices, it is crucial to explore their self‐assembling characteristics, charge‐storage mechanisms, and coating efficacies. Herein, all these aspects are compiled with specific emphasis on peptide‐based systems for supercapacitor applications. The electrochemical charge storage mechanisms that are used for categorizing conventional supercapacitors with the theories and mechanisms outlining biological electron transfer, such as tunneling, hopping, superexchange, and flickering resonance, are collated. Furthermore, the characterization techniques solely pertaining to the study of such systems and their role in predicting the morphology of self‐assembly patterns which could directly impact the overall electrochemical properties are also addressed. Finally, some of the critical challenges associated with these systems while realizing their future potential in the field of sustainable energy storage devices are highlighted. [ABSTRACT FROM AUTHOR]

The presented scientific article discusses the changes taking place in isotactic propylene and metal nanoadditive nanocomposite before and after exposure to ETP (electrothermal polarization). Depending on the percentage of metal nanoadditive, the parameters of the electret state, mechanical and electrical strength of the samples of various supramolecular structures before and after ETP have been considered. It was found that, depending on the percentage of metal nanoadditive incorporated into the polymer, a decrease in its electrical and mechanical strength was observed both before and after ETP. Along with this, there is an increase in the parameters of the electret state. [ABSTRACT FROM AUTHOR]

The article analyzes the role of hydrogen bonds and supramolecular structures in enzyme catalysis and model systems. Hydrogen bonds play a crucial role in many enzymatic reactions. However, scientists have only recently attempted to harness the power of hydrogen bonds in homogeneous catalytic systems. One of the newest directions is associated with attempts to control the properties of catalysts by influencing the "second coordination sphere" of metal complexes. The role H-bonding, and the building of stable supramolecular nanostructures due to intermolecular H-bonds, based on catalytic active heteroligand iron (Fe) or nickel (Ni) complexes formed during hydrocarbon oxidations were assessed via the AFM (Atomic-force microscopy) method, which was proposed and applied by authors of this manuscript. Th is article also discusses the roles of hydrogen bonds and supramolecular structures in oxidation reactions catalyzed by heteroligand Ni and Fe complexes, which are not only effective homogeneous catalysts but also structural and functional models of Oxygenases. [ABSTRACT FROM AUTHOR]

The increased focus on green energy storage devices and the related rapid advancement in biomedical technologies makes the investigation of biocompatible integrated systems with medical relevance increasingly important. Peptides and their assembled morphologies with their innate biocompatibility and biodegradability are emerging as promising candidates in this respect due to their structural attributes which can be easily tuned to form supramolecular 3D architectures with extended pathways for ionic mobility. However, to comprehend their applicability in energy storage devices, it is crucial to explore their self‐assembling characteristics, charge‐storage mechanisms, and coating efficacies. Herein, all these aspects are compiled with specific emphasis on peptide‐based systems for supercapacitor applications. The electrochemical charge storage mechanisms that are used for categorizing conventional supercapacitors with the theories and mechanisms outlining biological electron transfer, such as tunneling, hopping, superexchange, and flickering resonance, are collated. Furthermore, the characterization techniques solely pertaining to the study of such systems and their role in predicting the morphology of self‐assembly patterns which could directly impact the overall electrochemical properties are also addressed. Finally, some of the critical challenges associated with these systems while realizing their future potential in the field of sustainable energy storage devices are highlighted.

Liquid crystals have been extensively used in various applications, such as optoelectronic devices, biomedical applications, sensors and biosensors, and packaging, among others. Liquid crystal polymers are one type of liquid crystal material, combining their intrinsic properties with polymeric flexibility for advanced applications in displays and smart materials. For instance, liquid crystal polymers can serve as drug nanocarriers, forming cubic or hexagonal mesophases, which can be tailored for controlled drug release. Further applications of liquid crystals and liquid crystal polymers include the preparation of membranes for separation processes, such as wastewater treatment. Furthermore, these materials can be used as ion-conducting membranes for fuel cells or lithium batteries due to their broad types of mesophases. This review aims to provide an overall explanation and classification of liquid crystals and liquid crystal polymers. Furthermore, the great potential of these materials relies on their broad range of applications, which are determined by their unique properties. Moreover, this study provides the latest advances in liquid crystal polymer-based membranes and their applications, focusing especially on fuel cells. Moreover, future directions in the applications of various liquid crystals are highlighted.

Evolutionary selection ensures specificity and efficiency in dynamic metastable macromolecular machines that repair DNA damage without releasing toxic and mutagenic intermediates. Here we examine non-homologous end joining (NHEJ) as the primary conserved DNA double-strand break (DSB) repair process in human cells. NHEJ has exemplary key roles in networks determining the development, outcome of cancer treatments by DSB-inducing agents, generation of antibody and T-cell receptor diversity, and innate immune response for RNA viruses. We determine mechanistic insights into NHEJ structural biochemistry focusing upon advanced small angle X-ray scattering (SAXS) results combined with X-ray crystallography (MX) and cryo-electron microscopy (cryo-EM). SAXS coupled to atomic structures enables integrated structural biology for objective quantitative assessment of conformational ensembles and assemblies in solution, intra-molecular distances, structural similarity, functional disorder, conformational switching, and flexibility. Importantly, NHEJ complexes in solution undergo larger allosteric transitions than seen in their cryo-EM or MX structures. In the long-range synaptic complex, X-ray repair cross-complementing 4 (XRCC4) plus XRCC4-like-factor (XLF) form a flexible bridge and linchpin for DNA ends bound to KU heterodimer (Ku70/80) and DNA-PKcs (DNA-dependent protein kinase catalytic subunit). Upon binding two DNA ends, auto-phosphorylation opens DNA-PKcs dimer licensing NHEJ via concerted conformational transformations of XLF-XRCC4, XLF-Ku80, and LigIVBRCT -Ku70 interfaces. Integrated structures reveal multifunctional roles for disordered linkers and modular dynamic interfaces promoting DSB end processing and alignment into the short-range complex for ligation by LigIV. Integrated findings define dynamic assemblies fundamental to designing separation-of-function mutants and allosteric inhibitors targeting conformational transitions in multifunctional complexes.

Endotoxins or lipopolysaccharides (LPS), found in the outer membrane of Gram-negative bacterial cell walls, can stimulate the human innate immune system, leading to life-threatening symptoms. Therefore, regulatory limits for endotoxin content apply to injectable pharmaceuticals, and excess LPS must be removed before commercialization. The majority of available endotoxin removal systems are based on the non-specific adsorption of LPS to charged and/or hydrophobic surfaces. Albeit effective to remove endotoxins, the lack of specificity can result in the unwanted loss of essential proteins from the pharmaceutical formulation. In this work, we developed microparticles conjugated to anti-Lipid A antibodies for selective endotoxin removal. Anti-Lipid A particles were characterized using flow cytometry and microscopy techniques. These particles exhibited a depletion capacity > 6 ×103 endotoxin units/mg particles from water, as determined with two independent methods (Limulus Amebocyte Lysate test and nanoparticle tracking analysis). Additionally, we compared these particles with a non-specific endotoxin removal system in a series of formulations of increasing complexity: bovine serum albumin in water < insulin in buffer < birch pollen extracts. We demonstrated that the specific anti-Lipid A particles show a higher protein recovery without compromising their endotoxin removal capacity. Consequently, we believe that the specificity layer integrated by the anti-Lipid A antibody could be advantageous to enhance product yield. [ABSTRACT FROM AUTHOR]

A dynamically responsive hydrogel medium is prepared from two self‐assembling components, a polysaccharide (chitosan) and a surfactant (sodium dodecyl sulfate; SDS). It is shown that this medium can be patterned using an electrode "pen" to reconfigure supramolecular structure: cathodic writing induces neutral chitosan chains to form a crystalline network, while anodic writing generates cationic chitosan chains that electrostatically crosslink with anionic SDS micelles. Both supramolecular structures are re‐configurable and each is stabilized by structure‐induced shifts in chitosan's pKa, thus electronically written patterns can be erased, new patterns can be written, and patterns can be written in three dimensions. Further, it is shown that NaCl‐induced morphological transitions of the SDS micelles allow patterns to be reversibly concealed or revealed. To demonstrate the versatility of this medium for information storage, a quick response (QR) code is electronically written and it is shown that this code can be recognized by a standard cellphone app. This QR code can be concealed by making the medium opaque (i.e., by obscuring the pattern) or by making the pattern evanescent (i.e., by making pattern invisible). Overall, this work demonstrates that a dynamically responsive medium composed of simple, safe and sustainable components can be reversibly patterned with spatial and quantitative control using top‐down electronic inputs. [ABSTRACT FROM AUTHOR]

A series of dinuclear metallacycles of Mn(II), Co(II), Ni(II), Cu(II) and Cd(II) with 1,8-naphthalene dicarboxylic acid (H2NDC) with co-ligand such as 2,2′-bipyridine (bpy) or solvent molecules have been synthesized in a refluxed condition. One mononuclear Ni(II) complex has also been synthesized following the same synthetic procedure with NDC, bpy and pyridine. Among them two polymorphic structures have been isolated. The single crystal X-ray structures of all the metallacycles have been described along with Hirshfield surface analysis. [ABSTRACT FROM AUTHOR]

A new type of oligophenyl-siloxane was prepared by using a precursor and a route which are non-conventional. The synthesis iniciated with the obtention of Octakis(chloro-calcium-oxy)cyclotetrasilicate by depolymerization of Wollastonite in molten CaCl2. The cyclotetrasilicate was silylated with phenyl-chloro-diethoxy-silane originating a liquid siloxane whose molecules presented a cross-like structure (C-PhS). The crosses were subjected to hydrolysis and condensation under mild conditions promoting their crosslinking and the formation of oligomeric solids (C-OPhS). It was corroborated that, in the solid state, oligomers self-assemble through hydrogen bonding and/or π-π stacking due to their OH and phenyl groups. Because of this supramolecular structure formation, it was possible to find the crossbar width which varied between 10.8 and 11.4 Å. [ABSTRACT FROM AUTHOR]

It has recently been shown that the titer of the SARS-CoV-2 virus decreases in a cell culture when the cell suspension is irradiated with electromagnetic waves at a frequency of 95 GHz. We assumed that a frequency range in the gigahertz and sub-terahertz ranges was one of the key aspects in the "tuning" of flickering dipoles in the dispersion interaction process of the surfaces of supramolecular structures. To verify this assumption, the intrinsic thermal radio emission in the gigahertz range of the following nanoparticles was studied: virus-like particles (VLP) of SARS-CoV-2 and rotavirus A, monoclonal antibodies to various RBD epitopes of SARS-CoV-2, interferon-α, antibodies to interferon-γ, humic–fulvic acids, and silver proteinate. At 37 °C or when activated by light with λ = 412 nm, these particles all demonstrated an increased (by two orders of magnitude compared to the background) level of electromagnetic radiation in the microwave range. The thermal radio emission flux density specifically depended on the type of nanoparticles, their concentration, and the method of their activation. The thermal radio emission flux density was capable of reaching 20 μW/(m2 sr). The thermal radio emission significantly exceeded the background only for nanoparticles with a complex surface shape (nonconvex polyhedra), while the thermal radio emission from spherical nanoparticles (latex spheres, serum albumin, and micelles) did not differ from the background. The spectral range of the emission apparently exceeded the frequencies of the Ka band (above 30 GHz). It was assumed that the complex shape of the nanoparticles contributed to the formation of temporary dipoles which, at a distance of up to 100 nm and due to the formation of an ultrahigh strength field, led to the formation of plasma-like surface regions that acted as emitters in the millimeter range. Such a mechanism makes it possible to explain many phenomena of the biological activity of nanoparticles, including the antibacterial properties of surfaces. [ABSTRACT FROM AUTHOR]

Polymetallic complexes with covalently bridged metal centers that interact magnetically are important in the molecular magnetism field, with binuclear compounds receiving special attention because they represent the simplest type of multinuclear species with covalently bridged metal centers. Herein, we report the synthesis and properties of two new binuclear FeII complexes, namely, {[Fe(abpt-TPE)(NCS)2]2(bpym)}·2MeOH·2MeCN (1) and {[Fe(abpt-TPE)(NCS)2]2(bpym)}·2CH2Cl2 (2) (bpym = 2,2′-bipyrimidine). The crystal structure is analyzed at different temperatures, and its properties are analyzed by variable-temperature magnetic susceptibility and variable-temperature fluorescence emission spectroscopy tests. Variable-temperature magnetic susceptibility measurements of two binuclear compounds show different types of magnetic behavior. Complex 1 exhibits two-step spin transition behavior with an intermediate state near 150 K (Tc1 = 191 K, Tc2 = 111 K); 1 undergoes an [LS–LS] ↔ [LS–HS] ↔ [HS–HS] spin transition during thermal induction. On the other hand, complex 2 exhibits intramolecular antiferromagnetic coupling, with J = −0.47 cm−1. The analysis of correlations between the structural characteristics and different types of magnetic behaviors for two binuclear complexes, revealed that the different magnetic behaviors shown by the two complexes are attributable to different degrees of [FeN6] octahedral distortion caused by different lattice solvents, ligand strain and crystal stacking. [ABSTRACT FROM AUTHOR]

To solve the environment and health issues arose from the sulfur vulcanization, a facile and completely eco‐friendly method of latex‐assembly and in situ cross‐linking is developed to prepare fully bio‐based and high‐performance rubber films. The films are featured by a "reinforced concrete" structure composed of dynamically cross‐linked chitosan framework and unvulcanized deproteinized natural rubber (DPNR) matrix. The self‐assembly of DPNR latex particles and chitosan, as well as the in situ cross‐linking of chitosan in the film forming process are confirmed by transmission electron microscope and dynamic light scattering. As green rubbers without vulcanization, the as‐designed composite films possess excellent mechanic properties comparable to those of the sulfur vulcanized DPNR film, whose tensile strength and toughness reach 15.2 MPa and 77.6 MJ m−3 respectively. Moreover, the films exhibited appropriate permeability to moisture and achievable reprocessing, which have potential applications in wearable devices. [ABSTRACT FROM AUTHOR]

In the wake of increasingly serious challenges in oilfield production and energy utilization, oil and gas reservoirs with ultra‐low permeability have gained tremendous importance for global energy supply. In such reservoirs, hydraulic fracturing is an important stimulation measure. Here, to develop a high‐performance fracturing fluid, a novel type of water‐based thickener named FPM‐2 was exploited based on low‐molecular weight alcohol and hydrophobically associating polymers, labeled as AAOS, and synthesized using acrylamide, acryloyl acid, octadecyl dimethyl allyl ammonium chloride, and octadecyl methacrylate. Dissolution rate and scanning electron microscope results showed the system to be a fast‐soluble thickener with a spatially cross‐linked network structure. The viscosity of 0.8 wt% FPM‐2 reached up to 216 mPa·s. Investigation of the rheological behavior showed that the thickener, 1.4 wt% FPM‐2, could withstand a temperature up to 180°C after being sheared for 80 min at 170 s−1, and its viscosity was up to 53 mPa·s. The 0.6 wt% FPM‐2 sample also displayed excellent shear recovery properties and high viscoelasticity. The most fascinating aspect of FPM‐2 was that its unique formula imparted the thickener with characteristics such as enhanced self‐association, waterproof locking, and prevention of wax formation. In this research, the recovery value of core permeability exceeded 80%, and wax was precipitated as small‐sized particles that prevented pipeline blockage. Therefore, the use of this multi‐effect cleansing thickener should set the trend for the development of oil and gas resources. [ABSTRACT FROM AUTHOR]

The pH‐responsive nanoparticles are a promising drug‐carrier because they always showed sensitivity and specificity to the pH changes caused by the surrounding environment. Most of the therapeutic drugs are generally absorbed in the stomach and small intestine due to the pH‐responsive nanoparticles always release the cargos at acidic media, making them difficult to reach the lower part of the large intestine, as well as inhibiting the therapeutic effects. Herein, an alkaline media‐sensitive supramolecular nanoparticle, regarded as SACD/PEI NPs, is prepared. SACD/PEI NPs exhibit assemble/disassemble state by changing the pH, which is used to encapsulate the anti‐colon drug CSL. CSL@SACD/PEI NPs showed a high release rate of 86.1% for the encapsulated CSL at pH = 8.5 (mimic the colon micro‐environment), while keeping stable at pH = 1.2 (mimic the gastric acid micro‐environment). Meanwhile, CSL@SACD/PEI NPs exhibited low hemolysis, indicating they possess good biocompatibility. In cell experiments, CSL@SACD/PEI NPs had a similar inhibitory effect on colon tumor cell SW480 and showed low cytotoxicity to normal cells compared with free CSL. Furthermore, both free CSL and CSL@SACD/PEI NPs showed excellent apoptosis effects on tumor cell SMMC‐7721. We hope that CSL@SACD/PEI NPs could be the valuable base‐answered drug delivery candidate, and have potential application for colon tumor therapy. [ABSTRACT FROM AUTHOR]

This paper describes charge tunneling across mixed self‐assembled monolayers (SAMs) and investigates the effect of bottom electrode on molecular dilution and tunneling function in large‐area molecular junctions. Binary mixed SAMs are formed with organic molecular diode (2,2′‐bipyridyl‐terminated n‐undecanethiol (SC11BIPY)) and nonrectifying n‐alkanethiolate diluent (SCn; n = 8, 10, 16, 18) via coadsorption on different electrodes, namely Au and Ag. By taking advantage of self‐referencing feature of rectification, the tunneling–molecular dilution relationship is reliably examined. Notably, rectification ratio of mixed SAMs on the Ag electrode decreases with increasing the diluent's length, whereas that of analogous SAMs on the Au electrode oppositely increases. Simulation of rectification using a parallel circuit model and surface analysis with contact angle goniometry evidence that such an opposite trend is dominated by the supramolecular structural order, which arises from the difference in interthiolate distance between Au and Ag. This work demonstrates that the molecular dilution effect on tunneling can be reversed by varying the bottom electrode. [ABSTRACT FROM AUTHOR]

The article analyzes the role of hydrogen bonds and supramolecular structures in enzyme catalysis and model systems. Hydrogen bonds play a crucial role in many enzymatic reactions. However, scientists have only recently attempted to harness the power of hydrogen bonds in homogeneous catalytic systems. One of the newest directions is associated with attempts to control the properties of catalysts by influencing the “second coordination sphere” of metal complexes. The role H-bonding, and the building of stable supramolecular nanostructures due to intermolecular H-bonds, based on catalytic active heteroligand iron (Fe) or nickel (Ni) complexes formed during hydrocarbon oxidations were assessed via the AFM (Atomic-force microscopy) method, which was proposed and applied by authors of this manuscript. Th is article also discusses the roles of hydrogen bonds and supramolecular structures in oxidation reactions catalyzed by heteroligand Ni and Fe complexes, which are not only effective homogeneous catalysts but also structural and functional models of Oxygenases.

Endotoxins or lipopolysaccharides (LPS), found in the outer membrane of Gram-negative bacterial cell walls, can stimulate the human innate immune system, leading to life-threatening symptoms. Therefore, regulatory limits for endotoxin content apply to injectable pharmaceuticals, and excess LPS must be removed before commercialization. The majority of available endotoxin removal systems are based on the non-specific adsorption of LPS to charged and/or hydrophobic surfaces. Albeit effective to remove endotoxins, the lack of specificity can result in the unwanted loss of essential proteins from the pharmaceutical formulation. In this work, we developed microparticles conjugated to anti-Lipid A antibodies for selective endotoxin removal. Anti-Lipid A particles were characterized using flow cytometry and microscopy techniques. These particles exhibited a depletion capacity > 6 ×103 endotoxin units/mg particles from water, as determined with two independent methods (Limulus Amebocyte Lysate test and nanoparticle tracking analysis). Additionally, we compared these particles with a non-specific endotoxin removal system in a series of formulations of increasing complexity: bovine serum albumin in water < insulin in buffer < birch pollen extracts. We demonstrated that the specific anti-Lipid A particles show a higher protein recovery without compromising their endotoxin removal capacity. Consequently, we believe that the specificity layer integrated by the anti-Lipid A antibody could be advantageous to enhance product yield.

Biocompatible luminophores based on organic dyes, which have fluorescence characteristics that are highly sensitive to the properties of the solvating medium, are of particular interest as highly sensitive, selective, and easy-to-use analytical agents. We found that BODIPY dimers (2,2′-, 2,3′-3,3′-CH2-bis(BODIPY) (1–3)) demonstrate fluorescence characteristics with a high sensitivity to the presence of polar solvents. The intense fluorescence of 1–3 in nonpolar/low-polarity solvents is dramatically quenched in polar media (acetone, DMF, and DMSO). It has been established that the main reason for CH2-bis(BODIPY) fluorescence quenching is the specific solvation of dyes by electron-donating molecules (Solv) with the formation of stable supramolecular CH2-bis(BODIPY)·2Solv structures. Using steady-state absorption and fluorescence spectroscopy, time-resolved fluorescence spectroscopy, and computational modeling, the formation mechanism, composition, and structure of CH2-bis(BODIPY)·2Solv supramolecular complexes have been substantiated, and their stability has been evaluated. The results show the promise of developing fluorescent probes based on CH2-bis(BODIPY)s for detecting toxic N/O-containing compounds in solutions. [ABSTRACT FROM AUTHOR]

In the present work, a solid state environment‐friendly methodology has been adopted to produce self‐healing elastomers using commercial tire‐grade polybutadiene rubber (BR) and butyl rubber (IIR). The elastomeric chains were directly grafted with optimized dosages of maleic anhydride followed by reactive mixing with ring opening amine‐based adducts (e.g., 3‐Amino‐1, 2, 4‐triazole) to create acid/amide‐based supramolecular cooperative hydrogen bonds between elastomer chains, without any adverse effect on the intrinsic properties of the elastomers. Thus, modified elastomers in gum state were found to be have supramolecular cross‐linking, that is, without applying any conventional vulcanizing agents. The tensile strength and tensile modulus of Modified BR, that is, BR‐g‐MAH (Tz) were enhanced by ~3.5% and ~7.5% respectively compared to commercial BR due to incorporation of hydrogen bonding network. The modified elastomers were also found to be thermo‐responsive in which micro‐cracks were healed in presence of thermal stimuli. Such healing could have been observed due to presence of reversible hydrogen‐bonding based dissociation and association phenomenon. The thermo‐reversible supramolecular hydrogen bonding was observed in 1H NMR spectroscopy as well. Furthermore, such modified BR, when utilized in different pneumatic tire formulations, significantly improvement in dynamic property was observed as compared to tire formulation made using commercial grade BR. The modified elastomer showed potential to replace the commercial‐grade elastomers for various conventional elastomers applications especially in tire sidewalls, tire tread etc. Additionally, such modified BR may improve tire life cycle, and thereby, reduces tire‐waste generation. It may also find applications in non‐tire sectors like conveyer belts, sealing joints, impact protection etc. [ABSTRACT FROM AUTHOR]

Hydrothermal pretreatment (HTP) has long been considered as an efficient and green treatment process on lignocellulosic biomass for bioconversion. However, the variations of cellulose supramolecular structures during HTP as well as their effects on subsequent enzymatic conversion are less understood. In this work, bamboo holocellulose with well-connected cellulose and hemicelluloses polysaccharides were hydrothermally treated under various temperatures. Chemical, morphological, and crystal structural determinations were performed systematically by a series of advanced characterizations. Xylan was degraded to xylooligosaccharides in the hydrolyzates accompanied by the reduced degree of polymerization for cellulose. Cellulose crystallites were found to swell anisotropically, despite the limited decrystallization by HTP. Hydrogen bond linkages between cellulose molecular chains were weakened due to above chemical and crystal variations, which therefore swelled, loosened, and separated the condensed cellulose microfibrils. Samples after HTP present notably increased surface area, favoring the adsorption and subsequent hydrolysis by cellulase enzymes. A satisfying enzymatic conversion yield (>85%) at rather low cellulase enzyme dosage (10 FPU/g glucan) was obtained, which would indicate new understandings on the green and efficient bioconversion process on lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

Controlling the self-assembly of nanoparticle building blocks into macroscale soft matter structures is an open question and of fundamental importance to fields as diverse as nanomedicine and next-generation energy storage. Within the vast library of nanoparticles, the fullerenes-a family of quasi-spherical carbon allotropes-are not explored beyond the most common, C 60 . Herein, a facile one-pot method is demonstrated for functionalizing fullerenes of different sizes (C 60 , C 70 , C 84, and C 90-92 ), yielding derivatives that self-assemble in aqueous solution into supramolecular hydrogels with distinct hierarchical structures. It is shown that the mechanical properties of these resultant structures vary drastically depending on the starting material. This work opens new avenues in the search for control of macroscale soft matter structures through tuning of nanoscale building blocks., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

In Nature, most known objects can perform their functions only when in supramolecular self-assembled from, e.g. protein complexes and cell membranes. Here, a dendritic polymer is presented that inhibits severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with an irreversible (virucidal) mechanism only when self-assembled into a Two-dimmensional supramolecular polymer (2D-SupraPol). Monomeric analogs of the dendritic polymer can only inhibit SARS-CoV-2 reversibly, thus allowing for the virus to regain infectivity after dilution. Upon assembly, 2D-SupraPol shows a remarkable half-inhibitory concentration (IC 50 30 nM) in vitro and in vivo in a Syrian Hamster model has a good efficacy. Using cryo-TEM, it is shown that the 2D-SupraPol has a controllable lateral size that can be tuned by adjusting the pH and use small angle X-ray and neutron scattering to unveil the architecture of the supramolecular assembly. This functional 2D-SupraPol, and its supramolecular architecture are proposed, as a prophylaxis nasal spray to inhibit the virus interaction with the respiratory tract., (© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)

Photosensitive supramolecular systems have garnered attention due to their potential to catalyze highly specific tasks through structural changes triggered by a light stimulus. The tunability of their chemical structure and charge transfer properties provides opportunities for designing and developing smart materials for multidisciplinary applications. This review focuses on the approaches reported in the literature for tailoring properties of the photosensitive supramolecular systems, including MOFs, MOPs, and HOFs. We discuss relevant aspects regarding their chemical structure, action mechanisms, design principles, applications, and future perspectives. [ABSTRACT FROM AUTHOR]

In this study, densified wood was prepared by hot pressing after partial lignin and hemicellulose were removed through alkaline solution cooking. The tensile strength and elastic modulus of densified wood were improved up to 398.5 MPa and 22.5 GPa as compared with the original wood, and the characterization of its supramolecular structures showed that the crystal plane spacing of the densified wood decreased, the crystallite size increased, and the maximum crystallinity (CI) of cellulose increased by 15.05%; outstandingly, the content of O(6)H⋯O(3′) intermolecular H-bonds increased by approximately one-fold at most. It was found that the intermolecular H-bond content was significantly positively correlated with the tensile strength and elastic modulus, and accordingly, their Pearson correlation coefficients were 0.952 (p < 0.01) and 0.822 (p < 0.05), respectively. This work provides a supramolecular explanation for the enhancement of tensile strength of densified wood. [ABSTRACT FROM AUTHOR]

Metabolites are immensely important for the routine function of every cell and take part in numerous physiological processes. Yet, in excess amounts, metabolites can self‐assemble, giving rise to cytotoxic amyloid‐like structures. Such structures may underlie some of the pathological effects associated with inborn error of metabolism disorders characterized by metabolite accumulation due to genetic mutations. Furthermore, such assemblies may have a role in neurodegenerative disorders due to abnormal accumulation. On the other hand, metabolites were shown to form functional assemblies in various organisms. Interestingly, various proteins and peptides showing amyloidal properties also have physiological roles and have been used for the fabrication of functional nanomaterials. Following this notion, metabolite self‐assembly could also be utilized due to several advantages including exceptional biocompatibility, inexpensive production, facile modeling and biodegradability in vivo. Co‐assembly of metabolites resulting in high rigidity can be further used in different biomedical and nanotechnological applications. Metal‐coordinated metabolite assemblies can be used as electrocatalysts in energy harvesting applications. Consequently, the study of metabolite self‐assemblies is not only crucial in order to understand their role in normal physiology and in pathology, but can also uncover a new route in exploring the fabrication of organic, biocompatible structures for material sciences and various technological applications. [ABSTRACT FROM AUTHOR]

The role of ligands in the regulation of the catalytic activity of Ni-complexes (Ni(acac)2) in green process-selective ethylbenzene oxidation with O2 into α-phenyl ethyl hydroperoxide is considered in this article. The dual function of phenol (PhOH) included in the coordination sphere of the nickel complex as an antioxidant or catalyst depends on the ligand environment of the metal. The role of intermolecular H-bonds and supramolecular structures (AFM method) in the mechanisms of selective catalysis by nickel complexes in chemical and biological oxidation reactions is analyzed. [ABSTRACT FROM AUTHOR]

Effects of chitosan (CHS) to carboxymethylcellulose (CMC) mixing ratio (1:0; 4:1; 3:1; 2:1; 1:1; 1:2; 1:3; 1:4; 0:1), temperature (25; 45; 65; 85 °C), and pH (3.0; 3.5; 4.0; 4,5) on obtaining of macro- and micro-polyelectrolyte complexes (PEC) were investigated. Mixing ratio 1:2 and 25 °C maximized the biopolymers' interactions and the formation of macro-PECs (macroscopic structures), independent of the pH. Both macro- and micro-PECs (dispersed microscopic structures) were studied by SEM, FT-IR, XRD and TGA. Micro-PECs had a more homogeneous appearance, whereas macro-PECs presented porous network structures interspersed with heterogeneous-sized vacuoles. Attractive electrostatic interactions and hydrogen bonds were involved in PECs formation. Macro-PECs were amorphous, which is desirable for encapsulating technologically relevant compounds. Finally, macro-PECs had low thermal degradation rates, and micro-PECs were thermally more stable than the forming biomolecules separately. Therefore, both macro- and micro-PECs formed by CHS and CMC appeared as green materials for different techno-functionalities, some of which are currently being studied by our team.

It has recently been shown that the titer of the SARS-CoV-2 virus decreases in a cell culture when the cell suspension is irradiated with electromagnetic waves at a frequency of 95 GHz. We assumed that a frequency range in the gigahertz and sub-terahertz ranges was one of the key aspects in the “tuning” of flickering dipoles in the dispersion interaction process of the surfaces of supramolecular structures. To verify this assumption, the intrinsic thermal radio emission in the gigahertz range of the following nanoparticles was studied: virus-like particles (VLP) of SARS-CoV-2 and rotavirus A, monoclonal antibodies to various RBD epitopes of SARS-CoV-2, interferon-α, antibodies to interferon-γ, humic–fulvic acids, and silver proteinate. At 37 °C or when activated by light with λ = 412 nm, these particles all demonstrated an increased (by two orders of magnitude compared to the background) level of electromagnetic radiation in the microwave range. The thermal radio emission flux density specifically depended on the type of nanoparticles, their concentration, and the method of their activation. The thermal radio emission flux density was capable of reaching 20 μW/(m2 sr). The thermal radio emission significantly exceeded the background only for nanoparticles with a complex surface shape (nonconvex polyhedra), while the thermal radio emission from spherical nanoparticles (latex spheres, serum albumin, and micelles) did not differ from the background. The spectral range of the emission apparently exceeded the frequencies of the Ka band (above 30 GHz). It was assumed that the complex shape of the nanoparticles contributed to the formation of temporary dipoles which, at a distance of up to 100 nm and due to the formation of an ultrahigh strength field, led to the formation of plasma-like surface regions that acted as emitters in the millimeter range. Such a mechanism makes it possible to explain many phenomena of the biological activity of nanoparticles, including the antibacterial properties of surfaces.

Background: Knowledge of the stabilizing mechanisms of soil organic matter (SOM) is extremely important for numerous soil functions. For this, insight into the nature of organic matter through appropriate model concepts are crucial. Aims: For several years, a heated debate has emerged on the transformation and stabilization of SOM. In the present work, we try to contribute to this debate using molecular modeling and providing a comprehensive overview of the history of application of molecular modeling tools and developing structural concepts of SOM. Methods: Molecular modeling methods based on quantum and/or classical mechanics were used to model SOM and related properties including interactions with reactive surfaces of soil minerals. Results: Modeling of SOM aggregates revealed that hydrogen bonds and cation bridges are the main stabilizing factors in soil solution, whereas pH modifies the stability. The modeled supramolecular SOM aggregates exhibit physicochemical properties, similar to those of humic substances (HS) described in literature. The interactions of the HS models with surfaces in kaolinite nanopores led to a partial disintegration of the aggregates into individual molecules and/or smaller subaggregates. Conclusions: From the molecular modeling point of view, supramolecular microaggregate models that exhibit the properties of HS are stable in the soil solution. However, their binding to reactive mineral soil constituents can be also in the form of individual molecules or subaggregates. Thus, HS microaggregate stability is relative, depending on the interacting environment. This reconciles two points of view of HS: either as small molecules and/or supramolecular structures. [ABSTRACT FROM AUTHOR]

Background: Knowledge of the stabilizing mechanisms of soil organic matter (SOM) is extremely important for numerous soil functions. For this, insight into the nature of organic matter through appropriate model concepts are crucial. Aims: For several years, a heated debate has emerged on the transformation and stabilization of SOM. In the present work, we try to contribute to this debate using molecular modeling and providing a comprehensive overview of the history of application of molecular modeling tools and developing structural concepts of SOM. Methods: Molecular modeling methods based on quantum and/or classical mechanics were used to model SOM and related properties including interactions with reactive surfaces of soil minerals. Results: Modeling of SOM aggregates revealed that hydrogen bonds and cation bridges are the main stabilizing factors in soil solution, whereas pH modifies the stability. The modeled supramolecular SOM aggregates exhibit physicochemical properties, similar to those of humic substances (HS) described in literature. The interactions of the HS models with surfaces in kaolinite nanopores led to a partial disintegration of the aggregates into individual molecules and/or smaller subaggregates. Conclusions: From the molecular modeling point of view, supramolecular microaggregate models that exhibit the properties of HS are stable in the soil solution. However, their binding to reactive mineral soil constituents can be also in the form of individual molecules or subaggregates. Thus, HS microaggregate stability is relative, depending on the interacting environment. This reconciles two points of view of HS: either as small molecules and/or supramolecular structures. [ABSTRACT FROM AUTHOR]

Polypseudorotaxane (PPR) hydrogels formed by inclusion complexes between poly(ethylene glycol) (PEG) and α‐cyclodextrin (α‐CD) are highlighted as promising biomaterial for drug delivery. Here, we report a novel injectable PPR hydrogel containing graphene oxide (GO) for pH‐responsive controlled release of doxorubicin hydrochloride (DOX). Our results showed that the gelation rates of the PEG/α‐CD supramolecular structures could be tailored depending on the reagent concentrations. The formation of PEG/α‐CD inclusion complexes was confirmed by TEM and XRD, the latter further confirming that GO restricts their formation. The supramolecular hydrogels were easily loaded with DOX by simple addition into the PEG solution before the complex formation with the α‐CD solution. Noteworthy, disruption of ionic interactions between DOX and GO in the nanocomposite at pH = 5.5 resulted in higher DOX release than under physiological conditions (pH = 7.4). This pH dependence was barely observed in pure PPR hydrogel. These findings introduce DOX‐loaded supramolecular hydrogels nanocomposites as promising carriers for pH‐responsive and therefore localized, drug delivery systems. [ABSTRACT FROM AUTHOR]

Polymetallic complexes with covalently bridged metal centers that interact magnetically are important in the molecular magnetism field, with binuclear compounds receiving special attention because they represent the simplest type of multinuclear species with covalently bridged metal centers. Herein, we report the synthesis and properties of two new binuclear FeII complexes, namely, {[Fe(abpt-TPE)(NCS)2]2(bpym)}·2MeOH·2MeCN (1) and {[Fe(abpt-TPE)(NCS)2]2(bpym)}·2CH2Cl2 (2) (bpym = 2,2′-bipyrimidine). The crystal structure is analyzed at different temperatures, and its properties are analyzed by variable-temperature magnetic susceptibility and variable-temperature fluorescence emission spectroscopy tests. Variable-temperature magnetic susceptibility measurements of two binuclear compounds show different types of magnetic behavior. Complex 1 exhibits two-step spin transition behavior with an intermediate state near 150 K (Tc1 = 191 K, Tc2 = 111 K); 1 undergoes an [LS–LS] ↔ [LS–HS] ↔ [HS–HS] spin transition during thermal induction. On the other hand, complex 2 exhibits intramolecular antiferromagnetic coupling, with J = −0.47 cm−1. The analysis of correlations between the structural characteristics and different types of magnetic behaviors for two binuclear complexes, revealed that the different magnetic behaviors shown by the two complexes are attributable to different degrees of [FeN6] octahedral distortion caused by different lattice solvents, ligand strain and crystal stacking.

The study of cyclic peptides (CPs) and self-assembling cyclic peptide nanotubes (SCPNs) is pivotal in advancing applications in diverse fields such as biomedicine, nanoelectronics, and catalysis. Recognizing the limitations in the experimental study of these molecules, this article introduces CYCLOPEp Builder, a comprehensive web-based application designed to facilitate the design, simulation, and visualization of CPs and SCPNs. The tool is engineered to generate molecular topologies, essential for conducting Molecular Dynamics simulations that span All-Atom to Coarse-Grain resolutions. CYCLOPEp Builder's user-friendly interface simplifies the complex process of molecular modeling, providing researchers with the ability to readily construct CPs and SCPNs. The platform is versatile, equipped with various force fields, and capable of producing structures ranging from individual CPs to complex SCPNs with different sequences, offering parallel and antiparallel orientations among them. By enhancing the capacity for detailed visualization of molecular assemblies, CYCLOPEp Builder improves the understanding of CP and SCPN molecular interactions. This tool is a step forward in democratizing access to sophisticated simulations, offering an invaluable resource to the scientific community engaged in the exploration of supramolecular structures. CYCLOPEp is accessible at http://cyclopep.com/., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Main observation and conclusion: Polymer‐supramolecular double‐network hydrogels (PS‐DN hydrogels) often show much improved recovery rates than conventional double‐network hydrogels because of the fast self‐assembling properties, making them attractive candidates for tissue engineering and flexible electronics. However, as the supramolecular network is dynamic and susceptible to break under low strains, the overall mechanical properties of PS‐DN hydrogels are still limited. Here, we report the mechanical properties for PS‐DN hydrogels can be significantly improved by tuning the supramolecular network structures. A single amino acid change of the self‐assembling peptide can tune the assembled structures from nanofiber to nanoribbon. Such a microscopic structural change can greatly increase the Young's modulus (107.4 kPa), fracture stress (0.48 MPa), and toughness (0.38 MJ·m–3) of the PS‐DN hydrogels. Moreover, the structural change also leads to slightly faster recovery rates (< 1 s). We propose that such dramatically different mechanical properties can be understood by the impact of individual peptide rupture events on the overall network connectivity in the two scenarios. Our study may provide new inspirations for combining high mechanical strength and fast recovery in double network hydrogels by tuning the supramolecular network structures. [ABSTRACT FROM AUTHOR]

Combining the unique corona structure of worm‐like patchy micelles immobilized on a polymer fiber with the molecular self‐assembly of 1,3,5‐benzenetricarboxamides (BTAs) leads to hierarchical superstructures with a fir‐tree‐like morphology. For this purpose, worm‐like patchy micelles bearing pendant, functional tertiary amino groups in one of the corona patches were prepared by crystallization‐driven self‐assembly and immobilized on a supporting polystyrene fiber by coaxial electrospinning. The obtained patchy fibers were then immersed in an aqueous solution of a tertiary amino‐functionalized BTA to induce patch‐mediated molecular self‐assembly to well‐defined fir‐tree‐like superstructures upon solvent evaporation. Interestingly, defined superstructures are obtained only if the pendant functional groups in the surface patches match with the peripheral substituents of the BTA, which is attributed to a local increase in BTA concentration at the polymer fibers' surface. [ABSTRACT FROM AUTHOR]

Supramolecular chemistry of folic acid is studied and revealed by exploring its assembly and disassembly process in a liquid–liquid interface. Experimental and computational studies are conducted to understand the interfacial interactions of folic acid in a oil-in-water interface by investigating the role of folic acid's critical aggregation concentration (CAC), molecular arrangement, and intermolecular interactions at the molecular level. The folic acid's CAC, determined from the concentration-dependent UV–vis absorption spectra in water/methanol solvent system, is found to be 2.72 μ M. The sigmoidal behavior of folic acid's maximum absorbances with respect to different folic acid concentrations reveals the nature of the self-assembly dynamics and aggregative assemblies' formation by three signature phases, in which CAC lies in the second phase — the growth phase. The computational studies reveal the intermolecular interactions and molecular orientation of folic acid molecules. They interact each other via H2-bonding between carboxylic acid groups in two glutamate units and two amine groups in pteridine units and π – π interactions between pteridine units and phenyl units, orienting two units in a parallel stacked arrangement. Correlating the computed intermolecular interactions and structural orientation of folic acid with its solid-state crystal packing structure has provided strong evidence supporting its supramolecular chemistry and assembly dynamics to make nanoassemblies in a liquid–liquid interface. [ABSTRACT FROM AUTHOR]

Zinc (II) cation is an environmentally friendly metal, less expensive, easy to dispose of, and managed. Highly engineered symmetric systems can be built using zinc (II) atoms as the metal nodes of hybrid organic-inorganic supramolecular structures. In biological contexts, luminescent zinc-based nanoprobes are in growing demand. Specifically, they are currently employed to detect biologically and environmentally relevant analytes, in therapeutic drug delivery, and for bioimaging and diagnostic techniques monitoring aspects of cellular functions. This review will provide a systematic and consequential approach to zinc-based nanoprobes, including zinc-based MOFs and other zinc-based organized nanoparticles. A progression from detecting the biological target to the intracellular sensing/marking/carriage has been followed. A selection of significant cutting-edge articles collected in the last five years has been discussed, based on the structural pattern and sensing performance, with special notice to living cell bioimaging as the most targeted and desirable application.

Liposomal supramolecular strustures (SMS) are widespread in different areas of modern science [...]

Biocompatible luminophores based on organic dyes, which have fluorescence characteristics that are highly sensitive to the properties of the solvating medium, are of particular interest as highly sensitive, selective, and easy-to-use analytical agents. We found that BODIPY dimers (2,2′-, 2,3′-3,3′-CH2-bis(BODIPY) (1–3)) demonstrate fluorescence characteristics with a high sensitivity to the presence of polar solvents. The intense fluorescence of 1–3 in nonpolar/low-polarity solvents is dramatically quenched in polar media (acetone, DMF, and DMSO). It has been established that the main reason for CH2-bis(BODIPY) fluorescence quenching is the specific solvation of dyes by electron-donating molecules (Solv) with the formation of stable supramolecular CH2-bis(BODIPY)·2Solv structures. Using steady-state absorption and fluorescence spectroscopy, time-resolved fluorescence spectroscopy, and computational modeling, the formation mechanism, composition, and structure of CH2-bis(BODIPY)·2Solv supramolecular complexes have been substantiated, and their stability has been evaluated. The results show the promise of developing fluorescent probes based on CH2-bis(BODIPY)s for detecting toxic N/O-containing compounds in solutions.

Hydrothermal pretreatment (HTP) has long been considered as an efficient and green treatment process on lignocellulosic biomass for bioconversion. However, the variations of cellulose supramolecular structures during HTP as well as their effects on subsequent enzymatic conversion are less understood. In this work, bamboo holocellulose with well-connected cellulose and hemicelluloses polysaccharides were hydrothermally treated under various temperatures. Chemical, morphological, and crystal structural determinations were performed systematically by a series of advanced characterizations. Xylan was degraded to xylooligosaccharides in the hydrolyzates accompanied by the reduced degree of polymerization for cellulose. Cellulose crystallites were found to swell anisotropically, despite the limited decrystallization by HTP. Hydrogen bond linkages between cellulose molecular chains were weakened due to above chemical and crystal variations, which therefore swelled, loosened, and separated the condensed cellulose microfibrils. Samples after HTP present notably increased surface area, favoring the adsorption and subsequent hydrolysis by cellulase enzymes. A satisfying enzymatic conversion yield (>85%) at rather low cellulase enzyme dosage (10 FPU/g glucan) was obtained, which would indicate new understandings on the green and efficient bioconversion process on lignocellulosic biomass.