Search Results (2,966)

Self-healing conductive hydrogels have attracted considerable interest in recent research due to their applications in biomedical and electronic fields. The design and preparation of a functional self-healing conductive hydrogel that features multiple stimuli-responsive properties, adhesion, and tunable mechanical characteristics for a wearable electronic sensor is highly anticipated. In this work, we proposed a hydrogel sensor through free radical polymerization by using host molecule acryloyl-β-cyclodextrin (AC-β-CD), guest molecule of acryloyl-1-adamantanamine (AC-AD), N-isopropylacrylamide (NIPAM), and conductive reduced graphene oxide/β-CD (rGO-CD). The chemical and physical structure, conductivity, de-swelling/swelling behavior, photothermal behavior, mechanical performance, adhesive performance, injectable performance, and self-healing performance of the resultant hydrogels were comprehensively investigated. Human motion detection and cytocompatibility test of hydrogel further demonstrated its potential for wearable electronics applications. Overall, this supramolecular conductive hydrogel might open a new sight to develop a multifunctional flexible sensor. Full article

Environmental pollution constitutes an increasingly complex global challenge, largely driven by industrial expansion and the consequent release of toxic species such as Cd²⁺, Pb²⁺, Cu²⁺, Hg²⁺, Fe³⁺, As³⁺, and Rh³⁺ into natural ecosystems. These contaminants pose significant risks to environmental integrity and public health, motivating the development of analytical technologies capable of sensitive, selective, and reliable detection. In this context, graphene-based electrochemical sensors have emerged as versatile platforms for monitoring a broad range of analytes, particularly in environmental applications involving heavy-metal detection. The intrinsic physicochemical properties of graphene derivatives have enabled low detection limits, rapid response times, and tunable selectivity. Despite analytical advances, critical challenges persist regarding operational stability in complex matrices, inter-batch reproducibility, and robustness to interfering species, which continue to hinder large-scale deployment and real-world applicability. However, challenges remain regarding stability and performance in complex arrays, reproducibility, and resistance to interference, necessitating innovative strategies for functionalization and molecular recognition. This review article establishes a comparative framework based on functionalization strategies (covalent, non-covalent, and hybrid), the chemical nature of graphene (GO, rGO, and doping), and various types of polymers (conductors and insulators), using statistical metrics such as the limit of detection (LOD), linear range, working potential, stability, and interferences, employing a bibliometric analysis using the PRISMA 2020 methodology. This comparative framework enables analysis and explanation of performance trends, and the generation of design and functionalization recommendations for versatile applications, including criteria for reproducibility and sustainability. Full article

With the rapid intensification of industrial and agricultural activities, water contamination by heavy metal ions has emerged as a critical global challenge, gravely imperiling ecosystem stability and public health. Among the various remediation technologies, adsorption has been widely adopted due to its high efficiency, low-cost water treatment, and simplicity of operation. However, conventional inorganic or synthetic adsorbents often exhibit poor degradability and pose a risk of secondary contamination, substantially limiting their sustainable application. Consequently, the development of environmentally benign and renewable adsorbent materials has become a central research focus in this field. Recently, cellulose-based composite hydrogels, derived from renewable resources and characterized by excellent eco-friendliness and highly tunable three-dimensional porous structures, have attracted considerable attention as promising green adsorption materials. These hydrogels demonstrate outstanding performance in the efficient sequestration of heavy metal contaminants from aqueous environments. This review systematically summarizes recent advances in cellulose-based composite hydrogels for heavy metal removal, to elucidate the structure–performance relationships linking material fabrication strategies, structural modulation, and adsorption efficiency. First, we outline the principal construction approaches, including physical crosslinking, chemical modification, and supramolecular self-assembly, and comprehensively analyze how different synthesis routes regulate pore architecture, mechanical properties, and the distribution of surface functional groups. Second, the underlying adsorption mechanisms, primarily coordination complexation, electrostatic interactions, and ion exchange, are discussed in detail. Finally, recent studies on the adsorption of cationic heavy metals (e.g., Pb(II), Cu(II), and Cd(II)) and anionic oxyanions (e.g., As(III) and Cr(VI)) are critically reviewed, with particular emphasis on the relationships between selective adsorption performance, material design principles, and specific recognition mechanisms. Overall, this review provides a theoretical foundation and practical guidance for the design and development of next-generation water treatment materials with high adsorption capacity, excellent selectivity, non-toxicity, and strong environmental compatibility, followed by future research recommendations. Full article

Poly(amidoamine) (PAMAM) dendrimers are widely recognized as versatile nanocarriers due to their tunable architecture and ability to associate with bioactive molecules. In this study, generation 3 PAMAM dendrimers functionalized with triphenylphosphonium (TPP) were employed to investigate the association of structurally related phenolic compounds—caffeic acid, p-coumaric acid, and cinnamic acid—through either covalent conjugation or non-covalent encapsulation. Physicochemical characterization by NMR, dynamic light scattering, and zeta potential measurements revealed the formation of supramolecular aggregates rather than isolated dendrimer units, with hydrodynamic diameters ranging from 127 to 260 nm and positive surface charge across all formulations. Encapsulation efficiencies determined by HPLC reached 93.8% for caffeic acid, 78.9% for p-coumaric acid, and 71% for cinnamic acid, indicating differential association behavior. Molecular dynamics simulations over 1 μs supported these findings, showing stronger and more stable interactions for polar antioxidants, particularly caffeic acid, driven by hydrogen bonding and electrostatic interactions, while cinnamic acid displayed preferential binding in more hydrophobic dendrimer regions. Radical scavenging assays (DPPH• and ABTS•+) demonstrated that all formulations retained antioxidant capacity, although dendrimer association modulated scavenging kinetics. In cellular assays under oxidative stress, free caffeic acid exhibited the strongest immediate reduction of intracellular reactive oxygen species, whereas dendrimer-associated systems showed reduced but significant activity, consistent with decreased solvent accessibility and slower release predicted by simulations. Overall, these results highlight a trade-off between molecular retention and immediate biological efficacy, demonstrating that the mode of association governs antioxidant accessibility and performance. This combined experimental and computational approach provides a mechanistic framework for the rational design of dendrimer-based delivery systems aimed at balancing stability and functional activity. Full article

Self-healing materials (SHMs) are a class of bio-inspired materials capable of autonomously repairing damage, similar to how living organisms heal wounds. The core motivation behind SHMs is to extend the service life of components while enhancing safety and reducing maintenance or replacement needs. SHMs can be broadly categorized into intrinsic systems, which rely on reversible internal bonds (dynamic covalent or supramolecular interactions) to heal repeatedly, and extrinsic systems, which embed external healing agents (e.g., microcapsules or vascular networks) that are released upon damage to effect repairs. Researchers have demonstrated self-healing behavior in diverse material families, including polymers, metals, ceramics/cementitious materials, and protective coatings, thereby improving crack resistance, fatigue life, and reliability across aerospace, automotive, civil infrastructure, energy storage, and microelectronics applications. Advances in material design and additive manufacturing have started integrating SHMs into practical structures. However, challenges such as scaling up production, maintaining mechanical performance, and ensuring long-term durability remain. Reported healing efficiencies in self-healing materials typically range from ~50% to near-complete recovery (~100%), depending on material systems and testing conditions, highlighting key trade-offs between healing performance, mechanical integrity, and scalability. Overall, SHMs represent a promising strategy for creating safer and more sustainable engineering systems, with ongoing developments aimed at overcoming current limitations and expanding their capabilities. This review highlights key trade-offs between healing efficiency, mechanical performance, and scalability, providing insights into the design and application of next-generation self-healing materials. Full article

The photophysical processes and photochemical reactions of 1,4-di(azastyryl)benzene (1) derivative {[(E,E)-1](ClO₄)₂} were investigated by absorption, luminescence, and laser kinetic spectroscopy in the water solution. The observed photo processes include dimerization, E-Z isomerization, and intersystem crossing to the triplet state, as well as the complexation [(E,E)-1](ClO₄)₂ with cucurbit[7]uril (CB[7]). The [(E,E)-1](ClO₄)₂ dye dimerization was shown to be energetically more favorable in the excited state than in the ground state. The reversible photoinduced migration of the dye dication in the CB[7] cavity takes place as a result of partial exit of the [(E,E)-1]²⁺ from the cavity and its subsequent conversion to the (E,Z)-isomer in the excited state, which undergoes conversion to the initial complex of {[(E,E)-1]@CB[7]}²⁺ after returning to the ground state. This photoprocess is of interest in relation to the scientific problem of designing photocontrolled supramolecular machines. Full article

Hydraulic fracturing in ultra-deep reservoirs faces significant challenges, including high wellbore friction and inadequate thermal stability of conventional fracturing fluids. To address these issues, we developed a potassium formate-weighted fracturing fluid with delayed crosslinking, excellent friction reduction, and superior temperature resistance, using a hydrophobic associating polymer thickener and a multi-ligand organic zirconium crosslinker. The weighted fracturing fluid has a density of 1.4 g/cm³ and completes crosslinking within 300 s at 90 °C. It achieves a maximum friction reduction rate of 63.2%. Below 60 °C, the system relies on a supramolecular thickener network for low viscosity and friction reduction; above 60 °C, chemical crosslinking between the thickener and zirconium ions creates a dual-network structure that significantly enhances temperature and shear resistance. After 120 min of shearing at 200 °C and 170 s⁻¹, the retained viscosity reaches 75.3 mPa·s. Complete gel breaking is achieved by sodium bromate via an oxidation reaction. This dual-network delayed crosslinking system successfully reconciles the conflict between low wellbore friction and high-temperature proppant-carrying capacity. This work presents a superior weighted fracturing fluid for ultra-deep reservoirs, as well as an innovative technique for their development. Full article

Low-molecular-weight gelators (LMWGs) have attracted growing attention as versatile alternatives to conventional polymeric thickeners and gelators, owing to their ability to form three-dimensional fibrillar networks through non-covalent self-assembly and to undergo reversible sol–gel transitions in response to external stimuli. Among the various stimuli that can be exploited, pH represents a particularly attractive trigger given its direct relevance to biological and physiological environments. This review focuses on three categories of pH-responsive LMWGs that have shown notable progress over the past decade yet remain relatively underexplored in the literature. First, N-oxide-type hydrogelators are discussed, with emphasis on amide amine oxide-based surfactants and pyridine-N-oxide frameworks. The pH-dependent protonation of the N-oxide moiety modulates intermolecular hydrogen bonding, thereby governing self-assembly and gel formation. The structural versatility of these gelators enables rational tuning of aggregate morphology and confers clear pH and temperature responsiveness. Second, recent advances in phenylboronic acid-based LMWGs are highlighted. Although boronic acid derivatives have long been studied as dynamic crosslinking units in polymeric hydrogels, 3-isobutoxyphenylboronic acid was recently identified as the first example of phenylboronic acid functioning as an LMWG, in which gelation is driven primarily by hydrogen bonding and pH responsiveness is exploited for stimuli-triggered gel disruption rather than gel formation. Third, pH-responsive orthogonal self-assembly systems are reviewed. Representative examples include multicomponent hybrid hydrogels combining pH-activated LMWGs with polymer gelators for controlled drug release, pH-triggered self-sorting of two LMWGs without any polymeric component, and bio-based orthogonal hydrogels composed of a glucolipid LMWG and cellulose nanocrystals. For each system, both advantages and remaining limitations are critically assessed. Collectively, this review aims to provide a timely overview of emerging trends in pH-responsive LMWG research and to offer perspectives on the rational design of next-generation stimuli-responsive soft materials. Full article

Ten compounds have been prepared among them six different dioxido(pyridine-2,6-dicarboxylato)vanadate(V) compounds with piperazinium (H₂pip²⁺) (1·6H₂O), methylpiperazinium (H₂mepip²⁺) (2·5H₂O), ethylpiperazinium (H₂etpip²⁺) (3·3H₂O), isopropylpiperazinium (H₂isopip²⁺) (4·H₂O), phenylpiperazinium (Hphepip⁺) (5∙H₂O) and thiomorpholinium 1-oxide (HtmorO⁺) (6·2,6-H₂pydc·2H₂O) cations as counterions as well as methylpiperazinium (H₂mepip²⁺) salt of a mixed valence vanadium [VO(2,6-pydc)-(μ-O)-VO(H₂O)(2,6-pydc)]⁻ complex (7), thiomorpholin-4-ium vanadate (Htmor)VO₃ (8), hexa(thiomorpholin-4-ium) decavanadate hexahydrate (Htmor)₆[V₁₀O₂₈]·6H₂O (9·6H₂O) and organic salt cocrystal thiomorpholin-4-ium 6-carboxypicolinate pyridine-2,6-dicarboxylic acid (Htmor)⁺(2,6-Hpydc)⁻∙(2,6-H₂pydc)·2H₂O (10·2H₂O) via different pathways starting either from pyridine-2,6-dicarboxylic acid or its esters, and were structurally characterized by single-crystal X-ray diffraction. Extended hydrogen bonding interactions are present due to the presence of organic cations as well as due to the diverse roles of water molecules in the hydrogen bonding network. Centrosymmetric hydrogen bonding was found to be an important motif, and diverse supramolecular patterns were also observed due to a wide variety of C–H···O and π···π interactions stabilizing the crystal lattices. Full article

Supramolecular oleogel lubricants construct a three-dimensional network structure within base oils through gelator-mediated non-covalent interactions, such as hydrogen bonding, van der Waals forces, and π–π stacking. These materials demonstrate unique advantages in mitigating issues inherent to traditional lubricants, including leakage, volatility, creep, and poor heat dissipation. Focusing on structural design and performance regulation, this review systematically summarizes the current development of supramolecular oleogel lubricants in the fields of green lubrication, extreme operating conditions, and nanocomposite lubrication. Specifically, it outlines the structure-property relationships between gelators and base oils in green lubrication systems, and elucidates the applications in radiation-resistant, high-load-bearing, and intelligently responsive lubrication. Strategies for utilizing nanocomposite supramolecular oleogels to resolve nanomaterial dispersion challenges are discussed, and the latest advancements in engineering applications are illustrated. By summarizing the development of supramolecular oleogel materials, this work can provide theoretical references for the future design and preparation of these lubricants. Full article

The dynamic properties of spread and adsorbed layers of amyloid-like silk fibroin fibrils (ALF) differ significantly from the properties of native protein layers (RSF). In the former case, the dynamic dilational surface elasticity and the steady-state adsorbed amount are considerably lower than in the latter case. This high dynamic elasticity of RSF layers is close to that of the layers of solid nanoparticles and is provided by the spontaneous formation of various interconnected supramolecular structures at the interface. The ALF produced at elevated temperatures is also intertwined at the interface but does not form a continuous network. In this case, the layer properties are close to those of the layers of amyloid fibrils of globular proteins. If the ALF dispersion is purified from admixtures of unreacted protein molecules, the dynamic surface elasticity reaches about 140 mN/m, similar to the results for dispersions of amyloid fibrils of globular proteins. The admixtures of unreacted protein molecules of high surface activity significantly influence the dynamic surface properties participating in the self-assembly, thereby leading to a slight increase in the surface elasticity. At the same time, the ALF acts as an effective inhibitor of the formation of supramolecular structures in the surface layer for mixed systems. Under the influence of amyloid fibrils, neither the impurities nor the addition of native RSF lead to mechanical surface properties close to those of native fibroin systems. Full article

Acute kidney injury (AKI) presents a critical clinical challenge due to its rapid progression and lack of effective targeted therapies. The herbal combination of rhubarb and Salvia miltiorrhiza, a cornerstone of Traditional Chinese Medicine (TCM) for renal protection, shows promise, yet its bioactive components and mode of action remain incompletely understood. This study identifies and characterizes inherent nanoscale entities from this herbal pair as a novel nanotherapeutic platform. Self-assembled nanoparticles (designated RSNPs) were isolated from the ethanol extract via differential centrifugation. Comprehensive characterization revealed that RSNPs form stable nanostructures through spontaneous self-assembly, primarily driven by supramolecular interactions (e.g., π-π stacking and hydrogen bonding). UPLC-MS/MS quantification confirmed the co-assembly of multiple bioactive constituents within RSNPs. Network pharmacology and molecular docking initially predicted their synergistic action on AKI-related pathways. In a cisplatin-induced murine AKI model, RSNP administration markedly attenuated renal dysfunction and histopathological damage, mechanistically linked to the mitigation of oxidative stress (e.g., decreased MDA and increased SOD) and inflammation (e.g., downregulated TNF-α and IL-6). In vitro, RSNPs demonstrated enhanced cellular internalization and superior cytoprotection against cisplatin toxicity in renal tubular epithelial cells, significantly reducing apoptosis. These findings unveil that the therapeutic efficacy of the Rheum palmatum L.–Salvia miltiorrhiza Bunge pair is intrinsically embedded within its nanoscale architecture. RSNPs represent a new class of TCM-derived nanotherapeutics with a well-defined material basis and multimodal mechanisms, offering a promising strategy for AKI treatment. Full article

Traditional chemical hair dyes are associated with potential health risks, while botanical alternatives are often hampered by poor stability and limited color longevity. In this study, discarded squid ink was used to prepare bionic hair colorants of high performance. By synergizing ultrasound disruption with enzymatic hydrolysis, the crude ink aggregates were transformed into highly uniform squid ink melanin nanoparticles (SIMNPs) with size and zeta potential of ~174 nm and −37.5 mV, respectively. This effectively improved the solubility but reduced the steric limitation of natural melanin. To overcome the weak affinity between melanin and human hair, a biomimetic interface where Fe(III) ions act as supramolecular bridges was further engineered to stably bind the SIMNPs to hair keratin. Under optimized conditions (pH 8.0, 45 °C, and 80 min), the dyed hair achieved a natural deep black with a total color difference (ΔE*) of 68.79 ± 0.29, which was maintained at 63.19 ± 0.27 even after 13 consecutive water washing cycles. Unlike destructive oxidative dyes, this SIMNP dyeing system assisted by coordination-driven assembly preserved the native α-helical architecture and disulfide bond networks of hair keratin. Furthermore, the deposited SIMNP layer effectively protected hair fibers from ultraviolet (UV) damage due to its powerful UV-shielding capacity. Crucially, in vitro and in vivo evaluations confirmed the exceptional biosafety of this formulation, demonstrating robust cellular tolerance and absence of murine skin irritation. The work demonstrates a green, low-damage paradigm for the development of bio-based hair colorants of high performance and presents a promising pathway for the high-value utilization of marine by-products. Full article

Gene therapy relies on safe and efficient delivery systems, yet traditional viral vectors and synthetic polymers often fail to meet these requirements due to immunogenicity and biocompatibility concerns. This review highlights self-assembling short peptides as a highly programmable and biocompatible non-viral platform uniquely positioned to overcome these translational bottlenecks. To provide a comprehensive overview of next-generation gene delivery, we systematically trace the trajectory from fundamental chemistry to clinical applications. First, we elucidate the supramolecular interactions and mechanisms driving peptide–nucleic acid co-assembly. Second, we outline concrete design strategies, detailing how sequence engineering and environmental responsiveness dictate the formation of optimized nanomorphologies. Third, we critically analyze how these nanocarriers navigate critical physiological and intracellular barriers, with a specific focus on cellular uptake, endosomal escape, and cargo release. Finally, we demonstrate the platform’s versatility in emerging frontiers, particularly mRNA vaccines and CRISPR/Cas9 gene editing. We conclude by identifying current obstacles to clinical translation and proposing future directions centered on multifunctional integration and stimuli-responsive design. Full article

We report here a thorough study concerning the acylation reaction products of 8-hydroxyquinoline with 2-chloroacyl chloride, with new insights and clarifications in respect to the obtained products brought by NMR and X-ray studies. According to the reaction conditions we employed, three compounds could be obtained: 1-(2-chloro-2-oxoethyl)pyridin-1-ium chloride 10, 8-hydroxyquinoline hydrochloride 11, and the acylated product 8-(2-chloroacetoxy)quinolin-1-ium chloride 12. A certain influence of the catalyst and the used solvent was observed, and feasible explanations for product formations were furnished. The structure of the compounds was proved by using ¹H- and ¹³C-NMR spectra as well as single-crystal X-ray diffraction studies for compounds 12 and 11. According to X-ray crystallography, compounds 11 and 12 have a planar structure and exhibit an ionic crystal structure crystallized as a hydrochloride salt of the corresponding organic base. The crystal structures of both compounds are stabilized by intermolecular hydrogen bonds and π-π stacking interactions. In the crystals of compounds 11 and 12, the structural components are interconnected by a system of intermolecular hydrogen bonding, and a similar one-dimensional array is formed via hydrogen bonding and π-π stacking. The further assembling of the structure for 12 and 11 occurs with the formation of a three-dimensional supramolecular network. Full article