Search Results (378)

This study characterizes novel cross-linked polymeric composites based on bisphenol A glycerolate dimethacrylate (BPA.DM) as the primary matrix, incorporating 1-vinyl-2-pyrrolidone (NVP) or 2-hydroxyethyl methacrylate (HEMA) as active diluents, and modified with antimicrobial agents: zinc oxide (ZnO), copper(II) sulfate (CuSO₄), nanosilver (Ag), and benzethonium chloride (BEN). Release kinetics of active components into water and LH medium were measured over 20 days using HPLC (bisphenol A, benzethonium chloride), GF AAS (Cu, Zn, Ag), and GC–MS, revealing highest silver release from HEMA+Ag composites (1671 µg/L), substantial copper release from HEMA (354 mg/L) and NVP (319 mg/L) systems, while benzethonium chloride exhibited significantly lower migration. The effect of NVP- and HEMA-containing composites on the metabolism of the Cerrena unicolor was also assessed. Scanning electron microscopy (SEM) and optical profilometry confirmed extensive surface degradation by C. unicolor mycelium, manifesting as cracks, increased porosity, and altered surface across HEMA- and NVP-based composites after 21-day incubation. Biochemical analysis of the fungus post-culture liquids demonstrated that both composite types markedly enhanced extracellular laccase activity at all tested time points (7, 14, 21 days), with ethanol-sterilized samples inducing a slower-migrating laccase isoform identified via zymography. These materials also increased total protein concentration and superoxide anion radical levels while reducing phenolic compounds relative to controls. The findings demonstrate that antimicrobial-modified BPA.DM composites not only undergo controlled biodegradation by C. unicolor but crucially serve as potential laccase inducers, highlighting their dual utility in bioactive material design and fungal enzyme biotechnology. Full article

Temperature/pH dual-responsive hydrogels are a class of smart materials capable of undergoing reversible structural or functional changes in response to temperature and pH stimuli. Owing to their remarkable dual-stimuli-responsive characteristics, these hydrogels have demonstrated significant potential in various biomedical applications, including drug delivery, tissue engineering, and diagnostics technologies, making them a prominent research focus. Although considerable progress has been made in recent years, a systematic summary of the preparation methods, structural design strategies and complex biomedical applications of these materials remains conspicuously absent. Consequently, this review aims to comprehensively examine the latest advancements in this field. First, the primary preparation methods of temperature/pH dual-responsive hydrogels, including chemical crosslinking, physical crosslinking, and hybrid crosslinking, are introduced and compared. Subsequently, the main structural design strategies, including microsphere, core–shell and layered structures, and their corresponding fabrication processes are systematically elucidated. Finally, the recent progress of temperature/pH dual-responsive hydrogels in biomedical applications is discussed, including drug delivery, cancer therapy, biosensing and diagnosis, tissue engineering and regenerative medicine, as well as wound healing. Based on the current research progress, this review also outlines the major challenges in the development of temperature/pH dual-responsive hydrogels, and presents perspectives on future research directions. 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

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

The current lack of effective treatments for traumatic spinal cord injury (SCI) presents a significant challenge in managing the complex microenvironmental alterations that follow the initial trauma. This study developed an injectable alginate hydrogel dynamically cross-linked by tannic acid–zinc nanoparticles (TA@Zn NPs), which exerts neuroprotective effects through the sustained release of zinc ions (Zn²⁺) and antioxidant TA@Zn NPs. TA@Zn NPs were cross-linked with phenylboronic acid-modified sodium alginate (SA) to form an injectable gel system. In response to the acidic and ROS-rich microenvironment characteristic of SCI, the hydrogel undergoes degradation, thereby triggering the disintegration of TA@Zn NPs and the concomitant release of Zn²⁺, enabling sustained therapeutic delivery. In a rat model of contusion injury, the degradation of TA@Zn NPs and the sustained release of Zn²⁺ significantly reduced oxidative damage and promoted axonal regeneration, which in turn inhibited scar formation and enhanced the tissue’s antioxidant capacity. Consequently, the group treated with the Zn²⁺-releasing hydrogel exhibited significant recovery of motor function. Collectively, these results validate the dual-function integration of Zn²⁺ as a dynamic cross-linker and neuroprotective agent within injectable hydrogels as a robust strategy for SCI repair, presenting a clinically translatable paradigm for neural regeneration. Full article

The emergence of multifunctional wound dressings represents a significant transformation in the care of cutaneous tissue injuries, providing advanced solutions that surpass traditional dressings. This study is poised to fabricate multifunctional hydrogels through dual-dynamic cross-linking, integrating antibacterial and antioxidant properties, which are capable of accelerating wound healing while improving therapeutic outcomes. The hydrogel, which exhibits excellent adhesion, rapid self-healing ability, and on-demand removability, was synthesized employing poly(vinyl alcohol) (PVA)–borax as the backbone, followed by the incorporation of silk fibroin (SF), tannic acid (TA), and chitosan (CS). Total saponins of Panax notoginseng flower buds (PNF) with anti-inflammatory and angiogenic properties were loaded in porous structural materials yielding the PBCTS@PNF hydrogel. The prepared hydrogel exhibited outstanding antioxidant properties and cytocompatibility, along with favorable antibacterial capabilities, achieving inhibition rates of 84.30 ± 2.34% against Escherichia coli (E. coli) and 98.12 ± 0.76% against Staphylococcus aureus (S. aureus), respectively. Animal experiments demonstrated that PBCTS@PNF significantly reduced inflammation and promoted multidimensional tissue regeneration, encompassing re-epithelialization, neovascularization, and hair follicle regeneration, along with ordered collagen matrix organization, leading to substantially accelerated wound healing. The multifunctional PBCTS@PNF hydrogel provides a potent bioengineered therapeutic platform for wound healing management through the synergistic interplay among antibacterial, anti-inflammatory, and tissue regenerative functionalities. Full article

Biomass represents a vital and sustainable resource for developing renewable materials with the potential to replace petroleum-based chemicals. Paulownia wood has high cellulose content and a loose wood structure, giving it natural advantages as a biomass material. Therefore, in this study, Paulownia wood was selected as a lignocellulosic feedstock. An integrated pretreatment process combining a deep eutectic solvent (DES) with an organic solvent was employed to efficiently remove lignin and hemicellulose, yielding cellulose-enriched residues. Subsequently, high-intensity ultrasonication was applied to convert the residues into cellulose nanofibers and nanocrystals. Using the extracted cellulose and nanocellulose, a dual-crosslinked network composite hydrogel was fabricated. The structural, mechanical, thermal, swelling, and conductive properties of the hydrogel were systematically investigated. The results show that, compared with the blank group hydrogel, the addition of nanocellulose increased the maximum tensile strength and tensile strain of the composite hydrogel by approximately 113% and 81%, respectively; meanwhile, the compressive strengths of the nanocellulose-based hydrogels (0.04575–0.09060 MPa) are higher than that of the blank group hydrogel (0.04235 MPa), confirming that the incorporation of nanocellulose significantly enhances the mechanical strength and elasticity of the hydrogel. The introduction of an AlCl₃/ZnCl₂ solvent system imparts appreciable electrical conductivity. Furthermore, the composite hydrogel maintains structural integrity after full swelling, indicating good dimensional stability and reusability. This work not only presents a green and efficient strategy for valorizing Paulownia biomass but also offers a novel design route for high-performance conductive hydrogel materials, highlighting their potential application in areas such as flexible electronics and energy storage. Full article

This study presents a novel dual cross-linking method using Prunus mume concentrate (PMC) as a source of H⁺ and Ca²⁺ to enhance polysaccharide (sodium alginate/carboxymethyl chitosan/gelatin) microcapsule formation. The structure and release characteristics of microcapsules were influenced more by PMC pH than by its concentration. SEM results showed that as the pH decreased, the microcapsules had a more compact structure. The FTIR results showed that acid enhances hydrogen bonding and electrostatic interactions within the polysaccharide, leading to more stable microcapsule structures. XRD patterns showed that acid enhanced the stability of the polysaccharide crystal structure. Microcapsules significantly increased viable counts by 1 log(CFU/mL) in simulated gastric fluid (SGF) and 1.25 log(CFU/mL) in simulated intestinal fluid (SIF) after 3 h of digestion. This study provides a basis for investigating the dual cross-linking of natural plant concentrates and Ca²⁺ construction of polysaccharide microcapsules to enhance probiotic resistance. Full article

This study presents a headset-type biofluorometric gas sensor incorporating a CMOS camera for continuous, non-invasive monitoring of transcutaneous ethanol from the ear canal. The sensor employs alcohol dehydrogenase (ADH) to catalyze the NAD⁺-to-NADH conversion during ethanol oxidation, enabling quantitative measurement through NADH fluorescence detection (λ_ex = 340 nm, λ_em = 490 nm). The integrated system comprises a wireless CMOS camera, an ADH-immobilized cotton mesh enzyme membrane, UV-LED excitation source, optical bandpass filters, and a dual convex lens assembly housed in a 3D-printed headset powered by a lithium battery. Key improvements include a 3.5-fold enhancement in fluorescence collection efficiency achieved through optimized dual convex lens configuration. Systematic screening of seven cotton mesh materials identified Iwatsuki cotton mesh as the optimal enzyme immobilization substrate, exhibiting minimal autofluorescence and 14.2-fold higher water retention capacity compared to H-PTFE membranes. The glutaraldehyde-crosslinked ADH-immobilized cotton mesh maintained enzymatic activity for over 45 min with a 10-fold improvement in signal-to-noise ratio. The system demonstrated a dynamic detection range spanning 10 ppb to 10 ppm for gaseous ethanol and exhibited high selectivity against interfering volatile organic compounds in skin gas, including methanol, acetaldehyde, formaldehyde, and acetone. Human experiments validated the system’s practical performance. Following alcohol consumption, subjects wore the device for 50 min while real-time fluorescence monitoring captured dynamic ethanol concentration changes in the ear canal. The dose-dependent fluorescence response—approximately 2-fold higher at 0.4 g/kg versus 0.04 g/kg alcohol intake—correlated well with calibration data. This headset-type biofluorometric sensor enables unrestrained continuous monitoring of ear canal ethanol, providing a novel wearable platform for alcohol metabolism assessment with potential applications in health monitoring and clinical research. 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

Environmental fires pose a serious threat to energy security, ecosystems and public safety, whilst traditional halogenated flame retardants suffer from limitations such as high environmental residue risks and insufficient flame-retardant efficacy. In this study, sodium alginate (SA) was utilised as the matrix, with the incorporation of ammonium polyphosphate (APP) and phytic acid (PA), in conjunction with SiO₂-APTES surface modification, to prepare nitrogen–phosphorus synergistic bio-based flame-retardant gels. The present study systematically investigated the influence of the N/P molar ratio on the gelation kinetics, rheological behaviour, microstructure and flame-retardant performance of the gel. The study revealed a nitrogen–phosphorus coupled gas–solid two-phase synergistic flame-retardant mechanism. The results indicate that at an N/P ratio of 1/4, the gel forms a stable dual-network structure comprising ionic cross-links and Si–O–P covalent bonds. In the gas phase, the thermal decomposition of APP releases inert NH₃, which dilutes oxygen and quenches gas-phase radicals (·OH, ·H). In the condensed phase, the phosphate groups of PA-catalysed SA form Si–O–P covalent bonds with SiO₂ under the mediation of APTES, creating a dense, insulating char layer. In comparison with the control group (N/P = 0/0), the optimal gel sample (N/P = 1/4) demonstrated a 33% increase in shear stress, a 10% reduction in the peak heat release rate (HRR), a 75% decrease in total smoke production (TSP), and a 150% increase in char layer thickness after combustion, while maintaining adequate mechanical strength, thermal stability, and environmental friendliness. This work provides novel insights and strategies for the development of green, highly efficient flame-retardant materials for environmental fire prevention and control. Full article

Conventional powdered biochar encounters severe bottlenecks in practical water treatment, such as difficult separation, easy loss, and potential secondary pollution. This work aimed to develop recyclable and high-performance adsorbents by preparing iron-doped biochar/sodium alginate composite microspheres (BC/MBC500-ALF) through Fe³⁺ cross-linking. Using corn stalk biochar and KMnO₄-modified biochar as adsorbent components and sodium alginate (SA) as a green shaping matrix, SA formed a stable egg-box hydrogel network to convert powdered biochar into uniform microspheres. Batch adsorption experiments revealed that the optimal pH for oxytetracycline (OTC) adsorption was 9, with adsorption capacities of 136.28 mg/g for BC500-ALF and 182.91 mg/g for MBC500-ALF. Kinetic analysis showed that BC500-ALF followed pseudo-first-order kinetics (R² = 0.983) dominated by physisorption, while MBC500-ALF fitted pseudo-second-order kinetics (R² = 0.994) dominated by chemisorption. The maximum Langmuir adsorption capacities at 308 K were 220.75 mg/g and 495.05 mg/g, respectively. Thermodynamic parameters confirmed a spontaneous and endothermic process. The adsorption mechanisms involved hydrogen bonding, π–π stacking, electrostatic attraction, metal-bridging complexation, and Fe–Mn oxide-mediated redox reactions. SA exerted dual functions in structure stabilization and adsorption enhancement. This composite provides an efficient and eco-friendly approach for tetracycline antibiotic pollution control in aqueous environments. Full article

Coal gangue (CG) ranks among China’s most significant industrial solid by-products. In response to China’s carbon neutrality commitments and the growing emphasis on resource recycling, finding effective ways to valorize CG has emerged as a pressing concern. Based on the mineral composition and chemical composition characteristics of CG, this study systematically investigated the enhancement effects of three alkali activators (Na₂SiO₃, NaOH, and Ca(OH)₂) on the cementitious properties of CG. Through different dosage and compressive strength tests, the efficiency ranking of the three activators was determined as follows: Na₂SiO₃ > Ca(OH)₂ > NaOH. A 10% Na₂SiO₃ dosage combined with 28-day curing was identified as the optimal condition for achieving sufficient reaction and structural densification. Under these conditions, the compressive strength of CG cementitious material reached 6.4 MPa, representing an increase of 190.9% compared to the blank group (2.2 MPa), significantly superior to Ca(OH)₂ (69.55%) and NaOH (62.27%). X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analyses revealed that alkali activators function primarily by disrupting the crystalline framework of CG, promoting the cross-linking polymerization of silicon–aluminum monomers to generate dense cementitious products, thereby improving material performance. The Na₂SiO₃ is attributed to its “dual activation effect”, providing OH⁻ to create an alkaline environment while supplying reactive silicate ions (SiO₃²⁻) to accelerate N-A-S-H gel and C-A-S-H gel formation. These findings offer guidance for optimizing CG-based cementitious formulations for formula optimization and large-scale utilization of CG cementitious materials. Full article

Open-source bioprinting can broaden access to biofabrication, enabling existing systems to perform high-resolution tissue manufacturing. However, most of these focus on low cost, easy assembly, or specific biomaterial ink rather than making a robust standardized and modularized multifunction platform. In this study, we present CrystalCells, a user-friendly modular open-source bioprinting system centered on the TridentExtruder, a high-performance syringe extruder with extrusion/retraction capability and tool-free automated syringe coupling. The system enables the automated exchange of syringe, temperature-controlling, microscope, and pipette modules. Repeated syringe return-and-pickup cycles showed repositioning errors within ±20 μm, while the extruder generated pressures above 950 kPa and exhibited lower elastic deformation than the Replistruder 4 under the same pressure conditions. CrystalCells supported the extrusion of pre-crosslinked alginate, FRESH printing, and dual-biomaterial inks printing with automated exchange. A microscope module resolved stained HeLa cells and enabled layer-by-layer imaging for defect detection during printing. A thermoelectric module maintained the syringe barrel below 6 °C during the printing of an alginate–collagen biomaterial ink at 23 °C (room temperature), and a pipette module transferred 2–10 μL volumes with errors within ±0.5 μL. These results show that CrystalCells is an open-source modular biofabrication platform integrating printing, imaging, temperature control, and liquid handling within a single workflow. Full article

In this study, a non-typical luminescent organosilicone was synthesized through a click reaction and used as a cross-linker to cure hydroxyl-terminated dimethylsilicone oil at room temperature via the sol–gel process, followed by application as a coating on a glass surface. This organosilicone film functions effectively as a luminescent down-shifting (LDS) material. Additionally, the presence of methyl groups and voids in the structure imparts a low refractive index, allowing it to serve as an anti-reflective (AR) layer. Optical and structural analyses on organosilicone-coated glass samples were conducted, and the dual-functional layer was applied to the glass cover of a perovskite solar panel to evaluate its performance. The coating not only enhanced light transmission as an AR layer but also converted UV light into blue light, which was absorbed by the solar cell. The results indicated improved solar panel performance, particularly in short-circuit current (Isc), external quantum efficiency (EQE) in the UV wavelength range, and overall efficiency. Overall, this material is a promising candidate for solar panel applications owing to maximized UV absorption for LDS, preserved transparency of the top cover glass, and room-temperature gelation, which facilitates repair of the dual-functional coating. Full article