Search Results (291)

Osteoarthritis (OA) is a multifactorial degenerative joint disease characterized by chronic inflammation, progressive cartilage extracellular matrix (ECM) degradation, and impaired joint lubrication, creating a complex pathological microenvironment that remains challenging to treat. In this study, a glycosaminoglycan (GAG)-mimetic sulfated chitosan (SCS) was synthesized via chemical modification of chitosan by grafting sulfonic acid groups, aiming to address these pathological features simultaneously. The therapeutic potential of SCS in OA was systematically evaluated. In vitro results demonstrated that SCS significantly promoted ECM synthesis in chondrocytes. Tribological analysis further revealed that SCS effectively enhanced cartilage lubrication in OA porcine cartilage, as evidenced by a marked reduction in the coefficient of friction, which decreased by 19% under a 5 N load and by 30% under a 10 N load. PCR analysis showed that SCS treatment significantly upregulated chondrogenic-related genes. In addition, SCS exhibited pronounced anti-inflammatory effects by downregulating the expression of inflammatory and catabolic genes. Importantly, in vivo studies demonstrated that SCS effectively preserved cartilage ECM and alleviated synovitis. Collectively, these findings indicate that SCS can simultaneously promote cartilage matrix regeneration, improve lubrication, and suppress inflammation, thereby effectively alleviating OA progression in a complex pathological environment. This study highlights the potential of SCS as a multifunctional GAG-mimetic biomaterial for osteoarthritis therapy. Full article

Bletilla striata polysaccharide (BSP), a bioactive glucomannan derived from the traditional Chinese medicinal herb Bletilla striata, has garnered increasing attention in both the biomedical and food sectors due to its unique physicochemical properties and diverse biological activities. While existing reviews have partially covered BSP’s structural features or single-field applications, a systematic review integrating its structure–activity relationship, full-spectrum chemical modification strategies, and parallel advances in the dual core fields of biomedicine and the food industry remains lacking. This review systematically consolidates recent advances in BSP research, focusing on three interconnected aspects: (1) the structure–activity relationships of BSP, highlighting how molecular weight (10⁴–10⁵ Da), monosaccharide composition (mainly glucose and mannose with variable ratios), glycosidic linkages, and higher-order self-assembled structures (e.g., triple-helix conformation) dictate its functionality in biological systems and food matrices; (2) chemical modification strategies—including carboxymethylation, graft copolymerization, cross-linking, polysaccharide–trace element complexation, phosphorylation, acetylation, and cholesterylation—that overcome intrinsic limitations of native BSP to enhance solubility, targeting, bioactivity, and food-related functional properties; and (3) the expanding applications of BSP and its derivatives in biomedicine (hemostatic materials, tissue engineering scaffolds, drug delivery systems, immunomodulation, and antitumor effects) and in the food industry (as natural stabilizers, emulsifiers, functional additives, and bio-based packaging components). Compared with previously published reviews, this work establishes a complete closed-loop logical system from structural characterization to rational modification and cross-field application and provides the most up-to-date systematic summary of BSP research. Key challenges—such as an incomplete understanding of structure-function correlations, insufficient pharmacokinetic data, and a lack of standardized quality control—are discussed, and future research directions are proposed. This review aims to provide a systematic theoretical basis for advancing BSP as a versatile multifunctional material for applications in functional foods, nutraceuticals, and biomedical fields. Full article

To meet the requirements for passive heat dissipation and self-cleaning of aluminum alloy enclosures used in 5G base-station active antenna units (AAUs), a scalable surface modification strategy involving sandblasting, NaOH etching, and PFTEOS grafting was developed for 6061 aluminum alloy. Microscale rough structures were first constructed by sandblasting, and hierarchical micro/nano structures composed of microscale pits and nanoscale plate-like/coral-like features were subsequently formed through NaOH etching and boiling-water treatment. Finally, a low-surface-energy PFTEOS layer was grafted onto the structured surface to achieve superhydrophobicity. The effects of sandblasting pressure and etching time on surface morphology, chemical composition, wettability, and infrared emissivity were systematically investigated. The results show that sandblasting enhanced infrared emissivity by increasing surface roughness and promoting optical trapping, while NaOH etching further improved emissivity through the formation of hierarchical micro/nano structures and infrared-active AlOOH/Al₂O₃ phases. After PFTEOS grafting, the surface wettability changed from hydrophilic to superhydrophobic, while the high infrared emissivity was maintained. Compared with the untreated aluminum alloy, the modified surface exhibited a remarkable increase in water contact angle from 80.10° to 153.63° and infrared emissivity from 0.0102 to 0.8951. Moreover, the water contact angle remained above 150° after continuous water-jet impact, indicating good preliminary resistance to hydraulic shear. This work provides a feasible surface-engineering route for integrating high infrared emissivity and self-cleaning capability on aluminum alloy surfaces for outdoor thermal management applications. Full article

This study investigated the effect of post-silanization processing on the surface chemistry and dispersion stability of 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) nanoparticles intended for the reinforcement of dental photopolymer resins. The nanoparticles were silanized using 3-Methacryloxypropyltrimethoxysilane and subjected to different post-treatment protocols, including control, drying, and centrifugation. Particle morphology was examined using field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). Dispersion behavior was analyzed by dynamic light scattering (DLS) and zeta potential measurements, performed in triplicate (n = 3), while surface chemical modifications were evaluated using Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Post-silanization processing significantly influenced nanoparticle surface chemistry and dispersion stability. Centrifugation promoted the formation of Si–O–Zr and Si–O–Si linkages, reduced loosely adsorbed silane species, decreased particle agglomeration, and increased zeta potential magnitude, resulting in a more uniform hydrodynamic size distribution compared to the dried group (Z-average ≈ 814 nm, PDI ≈ 0.44). These findings suggest that post-silanization centrifugation acts as an interfacial selection mechanism that distinguishes covalently grafted silane from weakly adsorbed species. Within the limitations of this in vitro study, further investigations under varied conditions are required to confirm broader applicability. Full article

Gum arabic (GA) is a widely used natural hydrocolloid in food processing because its protein–polysaccharide architecture combines high water solubility, low bulk viscosity, and useful interfacial activity. These attributes make GA valuable as an emulsifier, encapsulating agent, and film-forming material, but native GA is constrained by source-dependent heterogeneity, limited antioxidant functionality, relatively high dosage requirements in some emulsions, and modest barrier and mechanical performance in dried matrices. This review synthesizes recent advances in chemical functionalization, enzymatic and oxidative grafting, physical fractionation and complexation, and Maillard-type bioconjugation as routes to tailor GA for food engineering applications. Emphasis is placed on process-relevant structure–property relationships, including dynamic adsorption, interfacial rheology, emulsifying and encapsulation efficiency, bulk rheology, powder glass transition and hygroscopicity, film barrier behavior, and release kinetics. Across beverage emulsions, spray-dried powders, coacervates, coatings, and delivery systems, the evidence shows that modification must be selected according to the dominant process bottleneck, such as adsorption kinetics, oxidative stability, drying behavior, or humidity-sensitive matrix mobility. This review also identifies priorities for translation, including model-ready measurements, the management of raw-material variability, scale-up-aware processing, and sustainability and regulatory practicality. Overall, modified GA emerges as a versatile platform for designing more robust, application-specific food colloids, encapsulates, and functional coatings. Full article

Natural fibers are among the most extensively exploited bio-based materials in industry due to their abundance, affordability, and biodegradability. However, their intrinsic properties often require improvement through chemical, mechanical, or enzymatic treatments to expand their applications. Phosphorylation is a highly effective chemical modification that enables the covalent grafting of phosphate groups onto the fiber backbone. These functionalities enhance hydrophilicity, anionic charge density, swelling capacity, and water uptake, while significantly improving flame-retardant performance. In addition, phosphorylation can reduce energy consumption and production costs in the manufacture of functionalized micro- and nanofibrillated fibers, as the increased swelling facilitates fibrillation. Consequently, phosphorylated fibers are suitable for water treatment, biomedical devices, construction materials, and other advanced materials. Dozens of reagents and various synthetic routes have been explored to perform this reaction, each producing materials with distinct properties. Phosphorus content remains the primary parameter used to assess modification efficiency. This literature review examines existing phosphorylation methods, including reagents, substrates, and characterization techniques, and discusses applications such as flame retardancy, thermal insulation, ion exchange, energy storage, electrodes, and battery recycling. It also briefly addresses key challenges, including limited hydroxyl accessibility, control of the degree of substitution, potential cellulose degradation, and scalability constraints. Full article

Eucommia ulmoides gum (EUG), a sustainable plant-derived natural polymer, was functionalized via three distinct routes, including vulcanization, epoxidation, and hydroxylation to yield vulcanized (VEUG), epoxidized (EEUG), and hydroxylated EUG (HEUG), respectively. We systematically characterized the effects of modification route and degree on the chemical structure, crystallization behavior, thermal stability, hydrophilicity, and mechanical properties of functionalized EUG and further evaluated the high/low-temperature performance, microstructure, and mechanical properties of the corresponding modified asphalt binders (VEMA, EEMA, HEMA) as a function of modifier type and loading. For VEUG, C-S cross-linking networks formed during vulcanization suppress EUG crystallization, enabling a rigid-plastic to elastic transition, while high-temperature cleavage of C-S bonds reduces its initial thermal stability. For EEUG, epoxidation breaks C=C double bonds and introduces epoxy groups to strengthen intermolecular interactions; subsequent ring-opening grafting of hydroxyl groups onto EEUG yields HEUG, which forms additional cross-links via dynamic hydrogen bonds. Increasing modification degree for both EEUG and HEUG reduces their number- and weight-average molecular weights with narrower distribution, diminishes crystallinity, enhances thermal stability and hydrophilicity, and drives a rigid-plastic to elastic transition, characterized by decreased strength (0.65 MPa < σ_HEUG < σ_EEUG < 10.18 MPa) and markedly improved ductility (143.6% < ε_EEUG < 262.0%, 679.9% < ε_HEUG < 1360.3%). In asphalt binders, VEUG’s cross-linked network endows VEMA with refined more abundant bee-like microstructures, drastically boosting high- and low-temperature performance: relative to pristine EUG-modified asphalt (EUGMA), VEMA’s DMT modulus decreases by 94%, and adhesion increases by 87%. EEMA forms covalent bonds with polar asphalt components via epoxy groups, while HEMA constructs a hydrogen-bonded cross-linked network; both effectively inhibit asphaltene aggregation. With increasing modifier loading, EEMA and HEMA exhibit increased modulus, reduced adhesion, and gradually improved high- and low-temperature performance, except for the non-significant high-temperature enhancement of HEMA at higher loadings. Full article

The rapidly growing concern over the hazardous impact of phthalates on the environment and public health has led to a critical need for alternative and environmentally friendly plastics. Plasticizers developed from natural materials represent one possible solution. This paper explores four types of renewable feedstocks (sorbitol/polyols, glycerin, cardanol from cashew nutshell liquid, and limonene from citrus peels) as sources for developing alternative plasticizer systems. Key areas explored include the type of feedstock utilized, the methods used for extracting or processing the feedstocks, the nature of the chemical modification processes (e.g., esterification, epoxidation, etherification, or reactive grafting) applied to generate the respective plasticizers, and the resultant physical and mechanical properties. The performance of each plasticizer system in polymers such as PVC, PLA, and polysaccharide-based bioplastics is evaluated, alongside the compatibility with biological tissues, toxicological properties, biodegradability, and chemical migration into food simulants. The feasibility of each family of plasticizers is also assessed from an economic perspective, including availability of the feedstocks, economies of scale associated with large-volume production, and competitive pricing relative to established petroleum-derived plasticizers. Overall, sorbitol/polyol and glycerin derivative families have reached a level of maturity that provides a good balance of processability, food-contact safety, and biodegradability. Cardanol-based systems provide an attractive option where aromatic functional groups and combined plasticization–stabilization effects are needed. Limonene-derived plasticizer systems appear promising for use in PLA, but their broader utility may be limited by volatility, strong odors, and susceptibility to oxidation. Common issues identified across all four families include chemical migration into food products, regulatory approval, and the need for detailed life-cycle assessments. Full article

This study presents a highly efficient and sustainable biocatalytic platform for bisphenol A (BPA) bioremediation through the covalent immobilization of laccase onto hierarchically functionalized cotton fibers. The immobilization strategy involved selective periodate oxidation of cellulose, grafting a hexamethylenediamine (HMDA) spacer arm, and glutaraldehyde activation, ensuring stable covalent attachment. Characterization via FTIR, SEM, and BET confirmed successful surface modification and high enzyme loading, achieving an immobilization yield of 90.5%. The immobilized laccase (CT-DA-HMD-Lac) exhibited significantly enhanced performance compared to the free enzyme, with a two-fold increase in maximum reaction velocity (V_max) and a 75% improvement in catalytic efficiency of action (V_max/K_m). Furthermore, the biocatalyst demonstrated superior robustness, maintaining high activity across broader pH and temperature ranges, and retaining 75% of its initial activity after 15 consecutive reusability cycles. Storage stability was also markedly improved, with 83% activity retention after 60 days. Practical application in BPA degradation showed 85% removal efficiency within 300 min, a 2.4-fold increase in the degradation rate constant over the free enzyme. These results highlight functionalized cotton as a promising, cost-effective, and scalable support for advanced enzymatic wastewater treatment and the remediation of persistent endocrine-disrupting chemicals. Full article

Surface modification can regulate surface properties through the design of surface structures and chemical compositions. Heparin has good anticoagulant properties and is widely used in the surface modification of blood-contact materials. However, the molecular structure of heparin has often been overlooked in terms of its application and further utilization in the design process. In this study, heparin was grafted onto substrate materials through polydopamine/polyethyleneimine co-deposition coating and connected with cysteine to obtain PP-Hep-Cys. The sulfhydryl content of PP-Hep-Cys reached about 2.06 nmol/cm², and the NO generation was about 0.2415 nmol/cm². In the absence of NO donors, the introduction of heparin contributed to the inhibition of platelets, but when NO donors were added, the inhibition of platelets was caused by the synergistic effect of heparinization and NO generation. In addition, the clotting time of PP-Hep-Cys was significantly prolonged compared with PP, and the hemolysis rate declined to 0.33 ± 0.01%. Regarding the adsorption performance of Cu²⁺, the adsorption capacity of PP-Hep-Cys was higher than that of PP-Hep and PP-Cys, and monolayer adsorption was dominant. Overall, these results indicated that heparin, as a spacer, and cysteine, as a ligand, exerted a synergistic effect on blood compatibility and adsorption. Full article

The present theoretical study proposes and unravels chemical graft modification using a novel voltage stabilizer (3-amino-5-chlorophenyl 3-fluorophenyl methanone, ACFM) to ameliorate electrical insulation performance, oxygen-resistant characteristics, and thermal stability of addition-cure silicone rubber (SiR) used for cable accessory insulation in power transmission systems. First-principles calculations demonstrate that chemically grafted ACFM introduces shallow hole and electron traps into addition-cure SiR macromolecules to respectively impede hole transport and restrict hot electron production. Through molecular dynamics and Monte Carlo simulation, the chemically grafted ACFM is verified to enhance chain segment coalescence and decrease oxygen compatibility of addition-cure SiR macromolecules due to its higher dipole moment, leading to a reduction in oxygen permeation and improvement in thermal stability of the SiR crosslinked material. It is indicated from first-principles oxidation reaction paths that chemical grafting ACFM contributes positively to the oxidative stability of addition-cure SiR. The improved abilities of charge trapping and withstanding high temperatures together with enhanced resistance to both oxygen infiltration and oxidation of the addition-cure SiR material, as unraveled on a molecular scale in this research, open an avenue for developing advanced polymer dielectrics applied in harsh environments. Full article

ZnMgAl layered double hydroxides (LDHs) were synthesised via coprecipitation, and oleic acid and stearic acid were grafted onto their surfaces via dehydration condensation to obtain two nano-lubricant additives, OA-ZnMgAl LDH and SA-ZnMgAl LDH. These surface modifications significantly improved the dispersion stability of ZnMgAl LDH in lubricating oil. Tribological tests showed that, at their respective optimal concentrations for friction reduction or wear resistance, ZnMgAl LDH, OA-ZnMgAl LDH, and SA-ZnMgAl LDH reduced the coefficient of friction by 3%, 20%, and 16%, and decreased the wear scar diameter by 7%, 9%, and 14%, respectively, compared with the base oil (XMP-Mobil 320). To clarify the lubrication mechanism, the wear morphology and chemical composition were analysed using 3D optical profilometry, X-ray photoelectron spectroscopy, scanning electron microscopy, and FIB-SEM. The results indicate that LDHs react with the steel surface under load and shear to form a multilayer protective film consisting of an inner oxide layer and an outer graphite layer, preventing direct contact between friction pairs. In addition, the rolling and filling effects of partially unreacted LDHs further reduce friction and wear. Full article

Enhancing the solubility and processability of graphene remains a critical challenge, limiting its integration into advanced materials systems. In this work, poly(tert-butyl acrylate) (PtBA) and poly(N-isopropyl acrylamide) (PNIPAM) were grafted onto graphene via controlled atom transfer radical polymerization (ATRP) to create well-defined polymer–graphene hybrids with tunable interfacial properties. ATRP enabled the synthesis of PtBA and PNIPAM homopolymers with narrow molecular weight distributions and systematically varied chain lengths (4–18 kDa), allowing direct correlation between polymer architecture and material performance. Notably, the thermos-responsive behavior of PNIPAM was strongly dependent on chain length, highlighting the importance of controlled polymer design. Raman and FTIR spectroscopy confirmed successful grafting and chemical modification of the graphene surface. In addition, pilot studies demonstrate the ATRP synthesis of PtBA-b-PNIPAM block copolymers and their hydrolysis to PAA-b-PNIPAM, providing a platform for future development of multifunctional graphene interfaces. Overall, this study establishes a versatile and precisely controlled route for engineering polymer-grafted graphene with enhanced solubility and tunable functionality, enabling broader applications in smart materials and hybrid nanocomposites. Full article

Poly(ethylene terephthalate) (PET) is a widely used commodity polymer owing to its low cost, excellent mechanical properties, and high processability. Chemical modification of PET surfaces to impart specific functionalities represents an effective strategy for transforming PET into high-value-added materials without altering its bulk properties. In this study, we investigated the surface functionalization of PET substrates using surface-initiated atom transfer radical polymerization (SI-ATRP). ATRP initiation sites were introduced onto PET surfaces through mild surface hydrolysis followed by polyethyleneimine coating. To further enhance the grafting density, an inimer-based strategy was employed, in which a bifunctional monomer containing both a polymerizable group and a latent initiation site was used to form hyperbranched polymer structures on the PET surface, thereby amplifying the number of active initiation sites. Using these modified PET substrates, SI-ATRP of functional methacrylate monomers was successfully carried out. Grafting of poly(2,2,2-trifluoroethyl methacrylate) imparted highly hydrophobic surface properties, yielding water contact angles above 120°, whereas grafting of poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) produced hydrophilic surfaces with contact angles below 20°. Surface characterization by X-ray photoelectron spectroscopy confirmed successful graft polymerization and effective surface coverage. While the macroscopic wettability was primarily governed by the chemical nature of the grafted polymers, the inimer-based initiation-site amplification significantly enhanced the surface electrostatic properties of the polycationic polymer–grafted surfaces, increasing the ζ-potential from approximately +20 mV to over +100 mV. Antibacterial tests using Escherichia coli K-12 as a model bacterium demonstrated that PET substrates grafted with poly([2-(methacryloyloxy)ethyl]trimethylammonium chloride) exhibited clear contact-active antibacterial activity, achieving up to 2-log reduction in viable bacterial counts after 3 h of contact incubation. These results highlight the importance of molecular-level control of grafting architecture and surface electrostatic properties in the design of functional antibacterial PET surfaces. Full article

Plant-parasitic nematodes (PPNs) cause big crop losses globally. Safe/reliable methods for their durable management strategies can harness various beneficial relationships among the plant immune system and related microbiomes. Molecular mechanisms basic to these relations reveal wide arrays of significant roles for plant-healthy growth. This review focuses on such relations of microbiomes to prime and immunize plants against PPNs. It also highlights molecular issues facing PPN-resistant varieties with possible solutions such as genetic breeding/engineering, grafting, PPN-antagonistic root exudates, and novel resistant cultivars. These issues call for optimal uses of various widespread groups of microbiomes. Related plant signaling hormones and transcription factors that regulate gene expression and modulate nematode-responsive genes to ease positive/negative adaptation are presented. Exploring PPN-resistance genes, their activation mechanisms, and signaling networks offers a holistic grasp of plant defense related to biotic/abiotic factors. Such factors relevant to systemic acquired resistance (SAR) via plant–microbe interactions to manage PPNs are stressed. The microbiomes can be added as inoculants and/or steering the indigenous rhizosphere ones. Consequently, SAR is mediated by the accumulation of salicylic acid and the subsequent expression of pathogenesis-related genes. To activate SAR, adequate priming and induction of plant defense against PPNs would rely on closely linked factors. They mainly include the engaged microbiome species/strains, plant genotypes, existing fauna/flora, compatibility with other involved biologicals, and methods/rates of the inoculants. To operationalize improved plant resistance and the microbiome’s usage, novel actionable insights for research and field applications are necessary. Synthesis of adequate screening techniques in plant breeding would better use multiple parameters (molecular and classical ones)-based ratings for PPN-host suitability designation. Sound statistical analyses and interpretation approaches can better identify genotypes with high-level, stable resistance to PPNs than the commonly used ones. Linking molecular mechanisms to consistent field relevance can be progressed via dissemination of many advanced techniques. The CRISPR/Cas9 system has been effective in knocking out both the OsHPP04 gene in rice to confer resistance against Meloidogyne graminicola and the GhiMLO3 gene in cotton to minimize the Rotylenchulus reniformis reproduction. Its genetic modifications in crops synthesized “transgene-free” PPN-resistant plants without decreased growth/yield. Characterizing microbiome species/strains needed to prime and immunize plants requires better molecular tools for fine-scale taxonomic resolution than the common ones used. The former can distinguish closely related ones that exhibit divergent phenotypes for key attributes like stability and production of enzymes and secondary metabolites. As PPN-control strategies via tritrophic interactions are more sensitive to the relevant settings than chemical nematicides, it is suggested herein to test these settings on a case-by-case basis to avoid erratic/contradictory results. Moreover, expanding the use of automated systems to expedite detection/count processes of PPN and related microbes with objectivity/accuracy is discussed. When PPNs and their related microbial distribution patterns were modeled, more aspects of their field distributions were discovered in order to optimize their integrated management. Hence, the feasibility of site-specific microbiome application in PPN–hotspot infections can be evaluated. The main technical challenges and controversies in the field are also addressed herein. Their conceptual revision based on harnessing novel techniques/tools is direly needed for future clear trends. This review also engages raising growers’ awareness to leverage such strategies for enhancing plant resistance and advancing the microbiome role. Microbiomes enjoy wide spectrum efficacy, low fitness cost, and inheritance to next generations in durable agriculture. Full article