Search Results (3,649)

Peripheral nerve injuries involving critical-sized gaps remain a major clinical challenge. Although autologous nerve grafting is considered the gold standard for peripheral nerve repair, its clinical application is limited by the availability of donor nerve tissue and the risk of donor-site morbidity, including sensory deficits and functional impairment. Therefore, nerve guidance conduits (NGCs) have emerged as a promising alternative when combined with bioactive modulation strategies. In this study, we evaluated bisvinyl sulfonemethyl (BVSM)-crosslinked gelatin conduits integrated with electrical stimulation (ES) at different frequencies (0, 2, 20, and 200 Hz) in a rat sciatic nerve defect model over a 4-week recovery period (n = 10 per group). Structural regeneration was assessed by morphometric analysis, electrophysiology, macrophage infiltration, CGRP immunoreactivity, retrograde Fluorogold tracing, quantitative PCR of growth factors and inflammatory cytokines, and behavioral testing. Among all stimulation paradigms, low-frequency ES at 2 Hz produced the most pronounced regenerative effects. The 2 Hz group demonstrated significantly greater axon number, axonal density, and regenerated nerve area compared with control and high-frequency groups (p < 0.05). Electrophysiological assessments revealed improved nerve conduction velocity, higher MAP amplitudes, and shorter latencies. Enhanced macrophage recruitment and elevated CGRP expression were observed, suggesting coordinated neuroimmune and neurochemical activation. Gene expression analysis indicated upregulation of neurotrophic factors and balanced inflammatory cytokine responses under low-frequency stimulation. In contrast, high-frequency stimulation (200 Hz) failed to enhance overall regeneration and showed reduced axonal metrics, suggesting possible overstimulation-associated suppression. Collectively, these findings demonstrate that BVSM-crosslinked conduits provide a stable and biocompatible regenerative scaffold, and that appropriately tuned low-frequency electrical stimulation (2 Hz) optimally enhances structural, molecular, and functional recovery. The integration of material engineering with bioelectrical modulation represents a promising strategy for next-generation bioelectronic interfaces in peripheral nerve repair. Full article

Fibroin-based films represent a promising platform for sustainable and bio-derived materials. Existing literature has mainly focused on isolated molecules, plasticizers, or chemical cross-linkers, and the function of complex, multi-component natural extracts as structure-modulating agents in fibroin films remains poorly understood. In this study, edible films containing mulberry leaf extract (MLE; 2–8 wt%) and fibroin (8 wt%) were prepared by solution casting, and their structures were investigated using spectroscopic, morphological, thermal, mechanical, and barrier property analyses. The results reveal that MLE induces concentration-dependent changes in film performance through multicomponent, non-covalent interactions with the fibroin. An approximately 187% increase in tensile strength was achieved at high MLE concentration, confirming effective physical reinforcement. The water vapor transmission rate decreased markedly from 0.888 to 0.170 g·h⁻¹·m⁻², indicating an enhanced moisture barrier, whereas oxygen permeability increased at higher extract loadings, suggesting localized chain rearrangements. High optical transparency in the visible region was maintained (79.95–83.77%), while UV response was selectively altered with extract concentration. Overall, the 8MLE formulation exhibited the most balanced performance. This study demonstrates that plant-derived extracts can serve as effective natural modifiers for tailoring fibroin film properties without inducing crystallization, offering a sustainable strategy for designing bio-based and edible protein film systems. Full article

Objective: The purpose of this systematic review is to evaluate the available scientific literature on the effectiveness of combining sodium hypochlorite and cross-linked hyaluronic acid (xHyA) as an adjunct to non-surgical periodontal treatment. Materials and Methods: Five electronic databases were searched. The study was traced using the PRISMA criteria and publications from ProQuest, Google Scholar, Springer Nature, Scopus, and PubMed. The randomized study was examined using the Cochrane Risk of Bias 2 (RoB) tool and two case series studies were reviewed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. Results: The systematic review included four studies (two RCT and two case series). Across the included studies, the adjunctive use of sodium hypochlorite/amino acid gel and cross-linked hyaluronic acid (xHyA) following subgingival instrumentation was associated with improvements in clinical periodontal parameters. Probing pocket depth (PPD) reduction ranged from 1.5 to 5.8 mm, clinical attachment level (CAL) gain ranged from 1.5 to 5.3 mm, and bleeding on probing (BOP) reduction ranged from 57.5% to 65.6%. The improvements were generally more pronounced in deeper periodontal pockets. Minor variations in intervention protocols were observed among studies. Conclusions: The adjunctive use of sodium hypochlorite and cross-linked hyaluronic acid in non-surgical periodontal therapy may be associated with improvements in clinical periodontal parameters, including PPD, CAL, and BOP, particularly in deep pockets. However, the available evidence is limited and heterogeneous, with small sample sizes and short follow-up durations. Therefore, these findings should be interpreted with caution, and further well-designed long-term studies are required. Full article

This study examined how the extraction medium used to obtain Quercus robur extracts influenced the properties of electrospun poly(vinyl alcohol) (PVA) mats intended for potential active packaging applications. Extracts prepared with 50% ethanol and with a choline chloride:lactic acid:water system were incorporated into PVA spinning solutions, and their effects on solution properties, fiber morphology, thermal behavior, crosslinking response, and polyphenol release were evaluated. The type of extraction medium affected both the electrospinning process and the structure of the resulting materials. Ethanol-derived extracts reduced solution viscosity and promoted the formation of thinner fibers, whereas systems containing the choline chloride:lactic acid:water-derived extract showed higher conductivity and lower electrospinning stability. Crosslinking with tannic acid in water led to the collapse of the fibrous structure, while ethanolic tannic acid treatment preserved the nanofibrous morphology more effectively. FTIR analysis indicated differences in intermolecular interactions within the polymer matrix, consistent with the observed changes in structural stability and release behavior. Thermal analysis showed that ethanol-derived extracts lowered the thermal stability of the PVA matrix, whereas the choline chloride:lactic acid:water-derived system altered the degradation pathway and increased the amount of solid residue formed during heating. Release studies demonstrated a rapid burst release for ethanol-based mats and a more sustained release profile for mats containing the choline chloride:lactic acid:water-derived extract. Selected extract-containing and ethanol–tannic acid-crosslinked mats also showed antibacterial activity against Staphylococcus aureus. The results showed that the extraction medium significantly affected polymer–extract interactions and the functional properties of electrospun PVA mats. At the same time, the conclusions refer specifically to the tested solvent systems, and broader generalization to other natural deep eutectic solvent-type formulations requires further comparative studies. Full article

Industrial synthetic and natural fibers play an indispensable role in modern manufacturing, aerospace, automotive, and textile engineering. However, the enhanced mechanical performance of advanced industrial fibers has introduced significant challenges in cutting processes, since brittle, high-tensile, and viscoelastic fibers exhibit totally different fracture behaviors from conventional solid materials. At present, the complex motion coupling mechanisms between fibers and cutting tools under free-form conditions are insufficient; there is no unified framework for understanding the mechanisms of fiber cutting; it is difficult to effectively link the microscopic fracture physics of different fiber types with their macroscopic cutting properties. Furthermore, research into the dynamic interaction between the cutting tool and the fiber, cross-scale cutting characteristics, and tool wear mechanisms has not been sufficiently systematic, and non-contact cutting methods have not yet been the subject of systematic study. Through a systematic review, this review identified three primary categories of difficult-to-cut industrial fibers and summarized the distinctions in their fundamental material properties. The static, kinematic, and dynamic characteristics of fiber cutting under both free and fixed forms were discussed. The fracture mechanisms of fibers under diverse loading scenarios were also systematically revealed. Furthermore, this review summarizes the effects of cutting tool wear characteristics, geometric parameters, and material types on cutting performance. Finally, non-contact methods for cutting fiber were listed. Based on the above analysis, three critical directions for future research were proposed to bridge the existing knowledge gaps in the literature. This review of the interdisciplinary interactions among mechanics, materials science, and textile engineering provides a theoretical foundation and research directions for achieving high efficiency and a long tool life during cutting industrial fibers. Full article

Fibrin gel, a protein-based polymer naturally generated during coagulation, has garnered attention in the biomedical field for applications such as fibrin glue, due to its specific physical and biological properties. Despite it, low mechanical strength and rapid degradation limited its utilization for biomedical applications. This study presents a reproducible protocol for the synthesis of pure fibrin hydrogels, aimed at achieving predictable structural properties through the precise calibration of fibrinogen and thrombin concentrations. By examining the mechanical and morphological characteristics, as well as the relationship between reagent concentrations and structural integrity, this research assesses impacts on swelling behavior, water absorption, and overall stability. Through a comprehensive analytical approach, we identified an optimal formulation, specifically 2.25 mg/mL fibrinogen and 1.375 U/mL thrombin, that effectively balances structural integrity with high cytocompatibility. The results demonstrate that this calibrated approach ensures high procedural reproducibility and a well-defined hydrogel architecture without the need for exogenous chemical cross-linkers. This work provides a robust methodological framework to overcome the common lack of reproducibility in fibrin-based hydrogel studies, positioning these materials as highly reliable candidates for advanced 3D in vitro models and biomedical applications. Full article

The development of sustainable encapsulation materials with tunable thermomechanical properties remains a critical challenge for photovoltaic reliability. Currently, the mainstream encapsulant for polycrystalline silicon solar cells is crosslinked EVA (Ethylene-Vinyl Acetate), which complicates the end-of-life recycling and reuse of modules. There is an urgent need to develop a novel encapsulant that combines excellent barrier properties with thermoplastic recyclability. Herein, we report a novel series of thermally decomposable CO₂-based thermoplastic polyurethane (PPC-TE) films engineered through the rational design of soft and hard segments. Utilizing polycarbonate diol (PPCDL) and polyether glycol (PEG) as soft segments, we systematically tailor material properties by modulating PEG-to-PPCDL ratios (5–20 wt%) and PEG molecular weights (1000–4000 g/mol). The optimized PPC-TE films exhibit excellent transmittance (>90%), adjustable glass transition temperature (T_g: 35.1 °C~11.6 °C), and remarkable mechanical adaptability (51~92 HA). The PPC-TE films exhibit water vapor permeability (WVP) as low as 14.8 g·mm·m⁻²·day⁻¹ and oxygen permeability (OP) of 4.13 cc·mm·m⁻² day⁻¹ at 15 wt% PEG content, surpassing commercial ethylene–vinyl acetate (EVA) encapsulants. Notably, these films demonstrate fully thermal decomposition above 350 °C, facilitating eco-friendly photovoltaic device recycling. Superior adhesion to glass substrates is evidenced by peel strengths up to 37 N/cm (PPC-TE2000-20) and the shrinkage rate is as low as 3%. This work contributes to improving the long-term stability of solar cells and has the potential for large-scale production. Full article

Light-responsive hydrogel-based oscillators typically exhibit small oscillation amplitudes because solvent diffusion is intrinsically slow, and their dependence on external periodic light modulation further results in limited amplitude, poor stability, and insufficient autonomy. Inspired by the trigger and sliding mechanism of the ancient crossbow, this study introduces an innovative system that integrates a sliding-block mechanism with time-delay feedback, breaking from conventional approaches that rely on hydrogel inertia or external modulation, within a purely theoretical and simulation-based framework. By establishing a nonlinear dynamic model coupling solvent diffusion, photoisomerization, and optical attenuation, this research shows through numerical simulations that the system can exhibit two distinct modes under constant illumination: a stable state and a self-sustained oscillatory state. The model predicts that the oscillation frequency can be flexibly tuned by varying key parameters, including the crosslinking density, Flory–Huggins interaction parameters of the spiropyran and hydrophilic polymer, ring-opening reaction rate, light intensity, fraction of light-sensitive molecules, and sliding displacement, whereas the initial absorption coefficient has only a minor influence. The slider displacement is also identified as an effective means to regulate the oscillation amplitude. Furthermore, the expansion force at the container bottom is predicted to oscillate synchronously with the hydrogel’s volume change. This theoretical framework represents a paradigm shift from “static small deformation” to “dynamic large-amplitude oscillation”, significantly enhancing the mechanical responsiveness of the material. This work provides a novel and controllable strategy for the conceptual design of autonomous light-driven micromechanical systems. Full article

Under long-term heavy load and complex service environments, polyurethane-modified asphalt (PUMA) struggles to simultaneously satisfy the requirements of rutting and cracking resistance of asphalt pavements, as cyclic stress loading reduces the elastic recovery and low-temperature toughness of polyurethane (PU). To address this issue, this study employed hydroxylated crumb rubber (HCR), which is obtained by activating the surface of crumb rubber (CR) and can chemically crosslink with PU in asphalt to form a crosslinked network structure. The aim was to enhance the rutting and cracking resistance of PUMA by utilizing the elasticity and low-temperature toughness of CR. An orthogonal design was employed to systematically design a modified asphalt formulation with PU and HCR (PU/HCRMA) by controlling the isocyanate index and the contents of PU and HCR. The basic properties, rheological properties, and viscoelastic properties of PU/HCRMA were systematically investigated. The results demonstrate that the rutting and cracking resistance of PU/HCRMA are substantially enhanced, with an improvement of 28.91% in the rutting factor at 64 °C compared to PUMA and a reduction of 49.93 MPa in the stiffness modulus at −24 °C. Simultaneously, incorporating HCR in PUMA enhances its viscosity and flow resistance while reducing temperature susceptibility. Furthermore, by providing load-bearing sites, HCR endows PU/HCRMA with exceptional elastic recovery and deformation resistance. Results from FTIR and FM confirm the reaction between isocyanate groups in the PU prepolymer and the hydroxyl groups on the surface of HCR and the formation of HCR-PU crosslinked networks. Finally, PU/HCRMA asphalt mixtures demonstrate significant improvements in both rutting and cracking resistance. This research outcome provides a new direction for the development of high-performance road asphalt materials. Full article

The widespread use of herbicides such as paraquat and glyphosate is a serious environmental and health concern due to their persistence, mobility, and toxicity in aquatic ecosystems. Composites of alginic acid (Alg) are prepared with carbonaceous materials such as graphene oxide (GO), carbon particles (CPs), porous carbon particles (PCPs), carbon black (CB), and carbon nanotubes (CNTs) were synthesized and evaluated as sorbents for the removal of cationic herbicide paraquat and the anionic herbicide glyphosate. The resulting Alg-based beads are environmentally safe because of the materials used during their preparation, such as a biopolymer, Alg, carbonaceous substances (GO, CPs, PCPs, and CB) as composite moieties, and Ca(II) ions as cross-linkers. The Alg–bead composite possessed strong swelling ability ranging from 1700% to 2500%, which led to swollen beads of spherical shape and an average diameter of 3 mm, each containing 20% of carbonaceous materials. Amongst all Alg-based beads prepared for paraquat and glyphosate removal from the aquatic environment, the highest adsorption capacity was attained for Alg–porous carbon particle (Alg-PCP) composites. The Alg-PCP beads were capable of adsorbing 85.7 ± 2.9 mg/g and 31.6 ± 2.2 mg/g from 50 mL of 250 ppm solutions of paraquat and glyphosate, respectively. In contrast, bare Alg beads adsorbed only 39.7 ± 1.8 mg/g and 12.9 ± 1.7 mg/g, respectively. A 250 mg Alg-PCP bead composite achieved a 91% removal of paraquat from a 50 mL solution containing 250 ppm of paraquat. These results show that Alg–PCP can be used to mitigate herbicide contamination in water, protecting aquatic ecosystems and addressing associated environmental and health risks. Full article

Introduction: Pancreatic cancer is one of the most lethal malignancies worldwide, and its incidence continues to rise. Periodontitis, a highly prevalent chronic inflammatory disease, has been linked to several systemic conditions, including a potential increase in pancreatic cancer risk. However, the available epidemiological evidence remains heterogeneous and fragmented. Objective: To evaluate whether periodontitis is associated with an increased risk of pancreatic cancer through a systematic review and meta-analysis of observational studies. Materials and Methods: A comprehensive search was conducted in PubMed, EMBASE, Web of Science, Scopus, the Cochrane Library, ClinicalTrials.gov, and the WHO regional databases, following PRISMA guidelines. Cohort, case–control, and cross-sectional studies assessing periodontitis through clinical parameters, radiographic measures, or tooth loss—and reporting pancreatic cancer risk (HR, RR, or OR)—were included. Risk of bias was assessed using the Newcastle–Ottawa Scale. Random-effects meta-analyses, meta-regressions, leave-one-out sensitivity analyses, influence diagnostics, publication bias assessment, and Trial Sequential Analysis (TSA) were performed. Results: Eight observational studies (primarily cohort designs) (n = 476,245 participants) met the inclusion criteria. Periodontitis was associated with an increased risk of pancreatic cancer (pooled HR = 1.56; 95% CI: 1.28–1.89), with moderate heterogeneity (I² = 55.5%). Sensitivity and influence analyses confirmed the robustness of the estimate. TSA showed a consistent trend, although the cumulative evidence remains insufficient for a definitive conclusion. Conclusions: Observational evidence suggests a modest statistical association between periodontitis and pancreatic cancer risk. However, the absolute risk increase is very small, and Trial Sequential Analysis indicates that cumulative evidence remains insufficient to establish causality or to support preventive or clinical recommendations. Further large-scale prospective studies with standardized periodontal assessments are required. Full article

3D Concrete Printing (3DCP) is increasingly explored as a digital fabrication technology offering design freedom, automation, and material efficiency. Nevertheless, its application in reinforced and long-life structures remains limited by insufficient understanding and poor comparability of durability performance, as previous reviews have not systematically linked methodologies to transport-related results. This study presents a systematic and critical review of carbonation and chloride ingress in 3DCP cementitious materials, conducted in accordance with the PRISMA methodology. Following a structured database search and two-stage screening process, the selected studies are subjected to qualitative analysis. Experimental methodologies, specimen typologies, exposure conditions, and attack directions are compiled and qualitatively compared. The review highlights pronounced methodological heterogeneity and frequent under-reporting of key parameters, particularly attack direction, sealing conditions, CO₂ concentration, and indicator methods, limiting cross-study comparison. Despite these limitations, consistent qualitative trends are identified. Printed specimens generally exhibit inferior durability performance than cast specimens, while cold joints are associated with increased penetration depth and result dispersion. Directional effects are non-negligible, although they are systematically addressed in only a limited number of studies. Overall, the findings emphasise the critical role of process-induced features and the need for harmonised testing methods to enable reliable durability assessment. 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

Massive pelagic Sargassum influxes along Caribbean coasts have created an urgent need for valorization routes for this biomass. Here, sodium alginate was extracted from Sargassum fluitans collected at Chuburná Beach, Yucatán, Mexico, using a multistep extraction involving 0.2% formaldehyde pretreatment at 4 °C and brief heating at 65–70 °C, and subsequently used to prepare calcium-crosslinked alginate nanoparticles by ionotropic gelation. To our knowledge, this is the first direct synthesis of alginate nanoparticles from non-commercial alginate extracted from pelagic S. fluitans. An extraction yield of 18.7 ± 0.05% (mean ± SD, n = 3) was obtained, and UV–Vis, FTIR, and NMR analyses confirmed the characteristic structural features of alginate. ¹H NMR revealed an M-rich composition (F_M = 0.61, F_G = 0.39; M/G = 1.54) with short guluronate blocks (N_G>1 = 2.42), whereas ¹³C NMR corroborated the presence of both β-D-mannuronic and α-L-guluronic acid residues. SEM images showed predominantly spherical-to-subspherical nanoparticles with representative dry diameters of 233–269 nm, whereas DLS measurements at 0, 24, and 72 h revealed a dominant volume-based nanoscale population with main peaks at 12.75–15.31 nm and PDI values of 0.229–0.291, indicating reasonable short-term colloidal stability at room temperature. These results demonstrate that pelagic S. fluitans can serve as a viable feedstock for the production of structurally preserved alginate and calcium-crosslinked alginate nanoparticles. The study supports converting recurrent Sargassum biomass into higher-value polysaccharide-based materials and provides a basis for future application-specific evaluation of these nanomaterials. Full article

The development of high-performance and sustainable carbon electrodes is increasingly important for next-generation supercapacitors, yet controlling heteroatom doping and hierarchical pore evolution in biomass-derived carbons remains a key challenge. Lignin, as an abundant aromatic biopolymer, offers a structurally rich platform for designing functional carbons, but its rigid cross-linked architecture limits precise pore regulation and efficient nitrogen incorporation. In this work, nitrogen-doped hierarchical porous carbons were engineered from enzymatically treated lignin through a synergistic urea-assisted nitrogen doping and KOH activation strategy. The urea–KOH co-activation drives the coordinated evolution of micropores and mesopores. This approach yields an optimized carbon material possessing a high BET surface area of 2569 m² g⁻¹, an interconnected micro–mesoporous architecture, and a favorable distribution of pyridinic, pyrrolic, and graphitic nitrogen species. The engineered pore hierarchy is correlated with enhanced ion transport kinetics, as evidenced by a high b value of 0.99 and a capacitive contribution of 98.5% at 100 mV s⁻¹; nitrogen functionalities introduce redox-active sites and improve interfacial wettability. As a result, the selected material delivers a high specific capacitance of 221 F g⁻¹ at 0.5 A g⁻¹, strong rate capability with 84.4% retention at 20 A g⁻¹, and excellent cycling durability with 90.7% capacitance retention after 50,000 cycles. This study demonstrates a potentially mechanistically informed, scalable pathway for coupling enzymatic structural regulation with chemical activation, offering a sustainable route for transforming lignin into high-value carbon electrodes suitable for advanced supercapacitor applications. Full article