Search Results (1,353)

Self-healing materials have attracted increasing attention as a strategy to enhance durability, extend service life, and reduce maintenance in advanced material systems. Among these, cellulose-based self-healing materials represent a sophisticated intersection between sustainable macromolecular chemistry and adaptive materials science. This review provides a synthesis of recent advancements in the field, systematically categorizing materials derived from cellulose raw materials. We evaluate the fundamental chemical strategies employed to achieve autonomous repair, distinguishing between extrinsic mechanisms—utilizing cellulose-based micro/nano-capsules to sequester healing agents—and intrinsic mechanisms governed by dynamic covalent chemistry (Schiff-base, boronic ester, Diels–Alder) and supramolecular interactions (hydrogen bonding, metal–ligand coordination, and host–guest assemblies). The analysis highlights how cellulose’s hierarchical structure and abundant surface functionality are leveraged to overcome the traditional trade-off between mechanical toughness and healing efficiency. Particular emphasis is placed on the transition from simple structural hydrogels to sophisticated multifunctional systems. These include ultra-stretchable strain and pressure sensors for e-skin applications, biocompatible and injectable matrices for chronic wound management and stem cell delivery, and advanced anti-freezing eutectogels for performance in extreme environments. Furthermore, we explore the integration of cellulose into traditional sectors, such as self-healing concrete utilizing microbe-induced calcification and smart, eco-friendly coatings for corrosion protection. Finally, we discuss critical challenges, including environmental stability, scalability, and the development of standardized evaluation protocols, providing a roadmap for the next generation of bio-derived, sustainable and intelligent materials. Full article

Chronic wound healing disorders are closely associated with microenvironmental imbalance, while traditional dressings fail to meet dynamic therapeutic demands due to limited functionality, poor responsiveness, and lack of controlled drug release. In this study, a smart hydrogel dressing was developed by integrating curcumin/Cu²⁺ co-loaded UiO-66-NH₂ metal–organic frameworks into a dynamically cross-linked oxidized hyaluronic acid/carboxymethyl chitosan (OHA-CMCS) network via Schiff base bonding. The MOFs served as a “one-carrier-dual-function” platform, enabling simultaneous delivery of Cu²⁺ and curcumin. The resulting Cur/Cu-MOF@OHA-CMCS hydrogel exhibited a porous structure, excellent self-healing ability, injectability, and favorable rheological and mechanical properties. Additionally, it showed pH-responsive degradation behavior and sustained drug release (~71% within 7 days). The hydrogel demonstrated effective anti-bacterial activity against both Escherichia coli and Staphylococcus aureus, along with good cytocompatibility (>70% cell viability). These results highlight its potential as a multifunctional and responsive dressing for chronic wound management. Full article

Moxifloxacin-based Schiff-base ligands provide a useful platform for tuning the coordination and biological properties of fluoroquinolone derivatives. Here, a moxifloxacin–salicylaldehyde hydrazone ligand (MOX-S) was prepared and coordinated with cobalt(II), nickel(II), copper(II), oxovanadium(IV), and gadolinium(III) ions to obtain a series of metal complexes. Citrate-stabilized gold nanoparticles (AuNPs) were also prepared and functionalized with MOX-S and the Cu(II) complex to evaluate the effect of nanoformulation on biological performance. The compounds were characterized using complementary analytical, spectroscopic, magnetic, thermal, and microscopic techniques. The combined data support 1:2 metal-to-ligand formulations for the complexes and indicate coordination mainly through the azomethine nitrogen and oxygen donor sites of MOX-S. In antimicrobial screening, the activity was strongly metal- and organism-dependent. Cu–MOX-S and VO–MOX-S showed the most pronounced activity against Gram-positive bacteria, with inhibition zones of up to 30 mm, while Cu–MOX-S displayed MIC values of 19.53 and 39.06 µg mL⁻¹ against Bacillus subtilis and Staphylococcus aureus, respectively. Cytotoxicity assays showed that MOX-S was more active than moxifloxacin against MCF-7 and HepG2 cells, while Cu–MOX-S showed enhanced potency, particularly toward HepG2 cells, with an IC₅₀ of 0.98 µM and a selectivity index of 5.97. AuNP formulations further increased the apparent antiproliferative potency in the tested cancer cell lines, giving sub-micromolar IC₅₀ values. Computational analyses, including DFT-based electronic descriptors and molecular docking, provided qualitative support for the experimentally observed coordination and cytotoxicity trends. Overall, metal coordination and AuNP formulations provide complementary strategies for modulating the physicochemical and in vitro biological behavior of this moxifloxacin-derived hydrazone scaffold. Full article

The cross-linked network structure of epoxy resins gives them excellent mechanical properties and heat resistance. However, it also makes them difficult to reprocess and recycle. This leads to environmental pollution and resource waste. Dynamic covalent bonds can make epoxy resins reprocessable. However, this involves a hard trade-off: adding flexible segments improves processing stability at the cost of mechanical strength, whereas keeping a rigid backbone retains the initial strength but leads to incomplete network reformation after multiple reprocessing cycles. As a result, performance continues to decrease. To solve this problem, this paper proposes a new strategy. It combines rigid cross-linked networks with alkyl dangling chains. The strategy does not sacrifice the rigid backbone of the epoxy. Instead, the alkyl dangling chains form physical entanglements during reprocessing. These entanglements compensate for the loss of chemical cross-linking density. Thus, the mechanical properties are retained or even enhanced. A vanillin-based Schiff base epoxy system was used. Alkyl dangling chains of different lengths were compared, and the results show that the system with longer alkyl dangling chains had higher mechanical properties after three reprocessing cycles; its tensile toughness increased by 85.7% compared to the system without dangling chains. At the same time, its thermal stability and glass transition temperature remained almost unchanged. This strategy effectively solves the conflict between strength and processing stability in reprocessable epoxy resins, as well as providing a new idea for designing green, high-performance, and closed-loop recyclable epoxy materials. Full article

Background: Oral colon-targeted delivery for inflammatory bowel disease (IBD) faces significant challenges, including limited gastrointestinal stability, premature drug release, and insufficient mucosal retention. Methods: To address these limitations, a mucoadhesive polysaccharide-based composite hydrogel incorporating prednisolone-loaded polymeric micelles was developed to enhance colonic delivery and promote mucosal repair. Amphiphilic oxidized dextran–oleylamine (ODEX-OA) copolymers were synthesized to self-assemble into prednisolone-loaded micelles. These micelles were subsequently embedded within a thiolated chitosan (CSSH) hydrogel through a Schiff base reaction, yielding the ODEX-OA-Pred-CSSH composite. The resulting system was comprehensively characterized for particle size, mucoadhesion, degradation, and pH/ROS dual-responsive drug release. Its colon-targeting capability and therapeutic efficacy were subsequently assessed in a dextran sulfate sodium (DSS)-induced colitis mouse model. Results: In vitro, the composite hydrogel demonstrated nanoscale micellar size, enhanced drug release kinetics under simulated inflammatory colonic conditions, and prolonged colonic retention for up to 24 h following oral administration. In vivo, studies confirmed that ODEX-OA-Pred-CSSH significantly alleviated colitis, evidenced by a reduced disease activity index, diminished pro-inflammatory cytokine levels, restored colon length, decreased spleen index, and improved histological mucosal repair. Conclusions: These findings collectively suggest that this mucoadhesive micelle–hydrogel composite represents a promising and effective oral colon-targeted platform for the treatment of IBD. Full article

This study reports the synthesis and characterization of a novel benzimidazole-derived Schiff base (BIMPB) via the condensation of (1H-benzo[d]imidazol-2-yl)methanamine with 1-phenylbutane-1,3-dione. The structure was confirmed using ¹H-NMR, ¹³C-NMR and FT-IR spectroscopy. Photophysical properties were extensively evaluated, revealing a strong S₀ → S₂ transition at 212 nm and fluorescence emission peaks at 396 and 410 nm, corresponding to π → π* and n → π* transitions. BIMPB demonstrated significant sensitivity to pH variations, exhibiting blue shifts of 11–23 nm across different environments. Furthermore, the compound acts as a fluorescent chemosensor for Cu²⁺ and Ca²⁺ ions, where coordination leads to a substantial reduction in fluorescence intensity accompanied by a distinct blue shift. The interaction between BIMPB and DNA was investigated using UV-Vis and fluorescence titration. The results showed a hypochromic effect and a minor shift in the absorption peak from 342 nm to 340 nm, suggesting a binding mechanism dominated by intercalation or electrostatic interactions. A high binding constant (K_b = 2.1 × 10⁵ M⁻¹) and a fluorescence quenching efficiency of 58.9% confirm the formation of a stable complex. Stern–Volmer analysis indicated a static quenching mechanism. These experimental findings, supported by molecular docking studies (binding energy = −8.3 kcal/mol), highlight the potential of BIMPB as a sensitive molecular probe for DNA-targeting and chemical sensing applications. Full article

The selective removal of beryllium from aqueous matrices remains a critical environmental and industrial challenge due to beryllium’s extreme toxicity, strong hydration chemistry, and the difficulty of separating Be²⁺ from chemically similar cations such as Al³⁺. In this study, a novel multidentate Schiff-base porous organic adsorbent, TFP-HEDA, was synthesized by condensation of 2,4,6-trihydroxybenzene-1,3,5-tricarbaldehyde (TFP) with N-(2-hydroxyethyl)ethylenediamine (HEDA) followed by urethane post-functionalization and systematically characterized by FTIR, ¹H/¹³C NMR, MALDI-TOF MS, elemental analysis, BET surface area analysis (617 m² g⁻¹), PXRD, and XPS. Batch adsorption experiments demonstrated rapid Be²⁺ uptake, achieving 90% removal within 20 min and equilibrium within 30 min. Among the isotherm models evaluated, the Langmuir model yielded the highest statistical consistency (R² = 0.9835, RMSE = 5.15 mg g⁻¹, χ² = 1.137) with a predicted maximum adsorption capacity of 163.93 mg g⁻¹ agreeing closely with the experimental value of 163.67 ± 6.42 mg g⁻¹ (deviation < 0.2%); this mathematical adequacy is interpreted as compatibility with a finite, saturable set of inner-sphere coordination sites rather than confirmation of a flat, energetically uniform surface, with chemisorption independently and more rigorously established by Dubinin–Radushkevich analysis (E = 28.87 kJ mol⁻¹) and post-adsorption FTIR and XPS evidence. Dubinin–Radushkevich analysis confirmed a chemisorption mechanism with mean adsorption energy E = 28.87 kJ mol⁻¹, consistent with inner-sphere Be²⁺–O/N coordination. Process optimization using response surface methodology based on a central composite design achieved 99% Be²⁺ removal at pH 5, an adsorbent dose of 60 mg/20 mL, and a contact time of 30 min (R² = 0.9892). Post-adsorption FTIR, XPS, BET, and TGA characterization confirmed framework integrity and the inner-sphere multidentate coordination mechanism. TFP-HEDA retained 82.4% of its initial capacity after nine adsorption–desorption cycles, demonstrating practical regenerability for Be²⁺ recovery applications. Full article

In this work, we elaborately designed two nickel(II) Schiff base complexes (NiL and NiL’) with different π-conjugated systems (benzene vs. naphthalene) to prepare uniform metallopolymer films with nickel(II) chelates as repeating units on ITO substrates through oxidative electropolymerization. The π-conjugation extending from the benzene moiety to the naphthalene moiety greatly enhances the electron delocalization of the metallopolymer film, resulting in a significant increase in optical contrast from 25% ([NiL]_n) to 80% ([NiL’]_n). The solid-state electrochromic devices based on metallopolymer film [NiL’]_n achieved a transmittance modulation of 71% and an electrochromic efficiency of 268.58 cm² C⁻¹. This work provides an effective strategy for developing low-cost and high-performance non-precious metal electrochromic materials through ligand conjugation engineering. Full article

The search for new anticancer agents with improved efficacy and reduced toxicity has intensified interest in metal-based compounds. In this study, two novel palladium(II) complexes, synthesized from Schiff base ligands derived from 5-chloro-salicylaldehyde and p-hydroxybenzylamine or tyramine, were chemically characterized and biologically evaluated. Both complexes exhibited significant cytotoxic activity against the MCF-7 breast cancer cell line in a dose- and time-dependent manner, with Pd2 showing slightly higher potency. Morphological analysis of treated cells indicated that apoptosis is the predominant mechanism of cell death. To gain deeper insight into the potential mechanisms underlying the observed anticancer activity, several biologically relevant targets were investigated. Enzyme kinetics revealed that the complexes act as uncompetitive inhibitors of liver catalase, suggesting a possible role in the induction of oxidative stress. Fluorescence studies demonstrated that Pd2 interacts with CT-DNA through combined intercalative and minor groove binding modes and exhibits significant binding affinity toward human serum albumin, predominantly at Sudlow’s site I. Molecular docking analysis further supported favorable interactions with catalase, estrogen receptor α, and B-form DNA, providing structural insight into the experimentally observed biological effects. Overall, the study explores multiple potential mechanisms of anticancer action, underscoring the promising therapeutic potential of these palladium(II) complexes, while antitumor activity has been initially assessed using a MCF-7 cell line as a preliminary model. Full article

Chronic wounds resulting from bacterial infection remain one of the main challenges in clinical practice. There is a pressing need to develop an injectable hydrogel sealant with multifunctional properties, including remodeling capabilities, self-healing, painless removal, and antibacterial activity, to promote tissue remodeling. In this work, aldehyde carboxymethylated agarose (ACMA) is employed for the first time as a bio-template. Dopamine (DA) is introduced onto the ACMA template via a reversible Schiff-base reaction, endowing it with biomineralization properties to synthesize DA-modified ACMA-Ag nanoparticles (ACMA-DA-Ag). Further, the prepared ACMA-DA-Ag, which possesses both antibacterial activity and injectable behavior, is incorporated into a guar gum hydrogel through the formation of borate/diol bonds, thereby forming a multiple-dynamic-bond crosslinked network. This hydrogel demonstrates adequate mechanical strength, injectability, remodeling capabilities, and self-healing performance. It can reassemble into a new hydrogel within 4 ± 0.6 min upon simple physical contact, and supports tissue adhesion. Furthermore, the hydrogel effectively covers irregular-shaped wound and can be removed without causing secondary injury. More importantly, this multifunctional hydrogel is cost-effective, easy to synthesize, and simple to use, significantly accelerating skin regeneration and promoting the formation of skin appendages, such as hair follicles. The outcome of this research not only serves a tissue sealant for wound healing, but also presents a new strategy for creating novel polysaccharide-based biomaterials. Full article

To develop a fully green and non-toxic wood adhesive with improved water resistance and bonding performance for soybean meal (Glycine max (L.) Merr.)-based adhesives, oxidized tannin (OTN) was obtained by the laccase treatment of waxberry tannin (TN), a natural polyphenolic polymer, and then blended with soybean meal (SM) to prepare an oxidized tannin–soybean meal adhesive (OTS). Laccase-mediated oxidation converted the tannin polymer into quinone-rich oxidized polymeric structures, which reacted with amino groups in soybean meal proteins through Michael addition and Schiff base reactions to form a covalently crosslinked polymeric network. Under the optimal conditions of a laccase dosage of 10%, an oxidation time of 6 h, an OTN:SM mass ratio of 0.5:1, and a hot-pressing temperature of 160 °C, plywood bonded with OTS exhibited a wet shear strength of 0.85 MPa at 63 °C, representing a 136% increase over that of the neat soybean meal adhesive, and showed slightly higher bonding performance than the commercial urea-formaldehyde (UF) resin under boiling-water conditions. Structural analyses (FT-IR and XPS) verified quinone formation and carbon–nitrogen single and double bonds. Thermal analyses (DSC and TGA) revealed improved curing reactivity and significantly enhanced thermal stability compared with the neat soybean meal adhesive. Full article

Conventional therapies for rheumatoid arthritis (RA) are limited by poor selectivity, insufficient modulation of the oxidative inflammatory microenvironment, and systemic side effects. Oxidative stress and macrophage-driven immune dysregulation represent critical therapeutic targets. Cinnamaldehyde (CA) and arginine (Arg) possess antioxidant, anti-inflammatory, and anti-osteoclastogenic activities, but their poor solubility, instability, and lack of targeting restrict clinical application. Here, we report a pH-responsive cinnamaldehyde–arginine nanoprodrug (Arg-CA NPs), synthesized via Schiff base reaction, that spontaneously self-assembles into uniform nanoparticles capable of acid-triggered dual-drug release. Arg-CA NPs enhanced the solubility and stability of CA, exhibited excellent dispersibility and circulatory stability, and demonstrated intrinsic antioxidant and anti-inflammatory properties. Mechanistically, Arg-CA NPs attenuated intracellular ROS accumulation, preserved mitochondrial function, and reprogrammed macrophages toward an anti-inflammatory M2 phenotype by suppressing hypoxia-inducible factor-1α (HIF-1α), cyclooxygenase-2 (COX-2), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling. In an adjuvant-induced arthritis (AIA) rat model, Arg-CA NPs selectively accumulated in inflamed joints and significantly alleviated joint swelling, synovial inflammation, cartilage erosion, and bone destruction. These findings identify Arg-CA NPs as a promising redox-active nanoplatform for RA therapy by targeting oxidative stress and immune dysregulation. Full article

Protein glycation is a nonenzymatic modification that links sugar chemistry to molecular aging and chronic disease. Sequential reactions involving Schiff bases, Amadori products, and reactive α dicarbonyl intermediates generate advanced glycation end products (AGEs) that irreversibly alter protein structure and function. AGEs also act as ligands for the receptor for advanced glycation end products (RAGE), initiating oxidative stress, inflammation, and tissue remodeling. This review synthesizes the molecular pathways of AGE formation, their structural diversity, and the biological factors influencing glycation kinetics. Advances in analytical detection methods—including fluorescence spectroscopy, LC–MS/MS, and immunochemical approaches—are highlighted for their role in monitoring AGE accumulation. Particular attention is given to the contribution of glycation to diabetes, cardiovascular disease, neurodegeneration, and cancer, alongside emerging therapeutic strategies to limit AGE formation or block AGE–RAGE signaling. Glycation thus represents a central mechanism in human disease pathogenesis and an emerging therapeutic frontier. Full article