To improve bread quality and mitigate the potential health risks associated with synthetic preservatives such as sodium dehydroacetate (SD), this study developed a natural preservative system composed of chitosan (CS) and fermented whey (FW) as an alternative. A series of bread formulations containing different ratios of CS and FW (0.5% CS + 0% FW, 0% CS + 0.5% FW, 0.5% CS + 0.5% FW, 1% CS + 0% FW, and 0% CS + 1% FW), along with 0% additive and 0.1% SD, were investigated. Among these, the composite of 0.5% CS and 0.5% FW was identified as optimal. Rheological analysis and scanning electron microscopy showed that this composite significantly enhanced dough viscoelasticity and promoted the formation of a stronger gluten network capable of effectively retaining gas. In subsequent bread quality assessments, the CS-FW composite markedly increased specific volume by 12.4% and slowed staling, whereas SD addition reduced specific volume by 27.2% and accelerated the staling process. During 42 days of storage, bread containing the CS-FW composite maintained aerobic plate count below 10 CFU g-1 and exhibited lower hardness and chewiness, higher elasticity, and more stable moisture, resulting in a shelf life extended approximately sixfold compared with the blank group. The CS-FW composite matched or exceeded the effectiveness of the synthetic preservative SD through a multi-targeted mechanism that simultaneously enhanced sensory properties and ensured microbial safety. This work provides a natural, dual-function approach for extending bread shelf life and improving overall product quality. © 2026 Society of Chemical Industry.

Chitosan nanocomposite films with metal nanoparticles: Synthesis, antimicrobial mechanisms and applications in sustainable packaging.

Rational design of composite gels demands innovative strategies to enhance structural and functional properties. Dietary fibers (DFs) offer promising potential for reinforcing protein-polysaccharide networks, but their role in soy protein isolate (SPI)-chitosan (CS) binary systems is underexplored. A novel ternary composite gel from SPI, CS and DF was developed to investigate DF-mediated reinforcement mechanisms. The synergistic combination of microbial transglutaminase (MTGase) cross-linking and heat treatment significantly enhanced the water holding capacity (WHC) of SPI-CS-DF, achieving the highest 30.32% increase compared to single treatments. SPI-CS with 1 mg mL-1 citrus dietary fiber (CDF) under the combined treatment exhibited the highest WHC (40.82% increase versus SPI-CS). Furthermore, texture analysis revealed that the addition of 5 mg mL-1 apple dietary fiber (ADF) and 5 mg mL-1 CDF increased gel strength by 37.31% and 36.27%, respectively. However, the addition of oat dietary fiber (ODF) simultaneously reduced the gel strength and hardness. Fourier transform infrared spectroscopy, scanning electron microscopy and confocal laser scanning microscopy demonstrated that ADF and CDF promoted uniform protein networks with porous structures, whereas ODF disrupted matrix continuity. MTGase-treated gels showed higher amide I peak intensity, which exhibited stronger covalent cross-linking. Overall, DF type and concentration are critical to tailoring SPI-CS gel structure and performance. MTGase-heat treatment combined with appropriate DF addition offers an effective strategy to improve WHC and mechanical properties in composite gels. These results provide a theoretical foundation for designing high-performance gel systems with potential applications. © 2026 Society of Chemical Industry.

Smart gel tectonics: 3D-printed starch-chitosan architectures with pH-responsive magnesium delivery for targeted intestinal repletion.

Oral mucositis is an inflammatory condition of the oral mucosa and causes pain associated with oral mucositis, leading to impaired quality of life. Localized drug delivery systems may provide effective treatment while avoiding the drawbacks of systemic administration. The purpose of this study was to formulate a buccal patch of lidocaine, fentanyl, and cetylpyridinium chloride using chitosan (CS), glycerol (G) and propylene glycol (PPG) to treat oral mucositis as a safe alternative to systemic administration. Solvent casting was used to create mucoadhesive buccal patches. Several characteristics were evaluated to optimize the buccal patch, including folding endurance, thickness measurement, mucoadhesion study, drug release, cell viability, permeation study and pharmacokinetic study. In addition, physicochemical interaction between CS, G and PPG was examined using FTIR, DSC and TGA. The optimized buccal patch BP4 showed a swelling index of 70%. All of the bioadhesive patches showed surface pH ranging from 6.2 ± 0.18 to 7.2 ± 0.18. Further, the BP4 had an adhesion force of 69 ± 3.06 × 10-3 N. The in vitro release of cetylpyridinium chloride, fentanyl and lidocaine from BP4 was 85%, 65% and 75%, respectively, for 12 hours. Ex vivo penetration study revealed 70%, 58%, and 78% penetration from three drugs, lidocaine, fentanyl, and cetylpyridinium chloride, respectively, from optimized buccal patches (BP4). When compared to suspension, the buccal administration of fentanyl and lidocaine in rabbits verified a notable increase in the bioavailability of the drugs. The developed mucoadhesive buccal patch represents a promising and safe localized delivery system for analgesic and antiseptic agents in the treatment of oral mucositis, offering sustained drug release and improved bioavailability.

Antifungal, antioxidant activity, and preservation effect of caffeic acid quaternary ammonium salt-modified chitosan.

W1/O/W2 emulsion gels stabilized by genipin-crosslinked chitosan/protein conjugates: Unveiling the impact of protein structure on their hierarchical microstructure, rheology, and controlled release of phycocyanin and astaxanthin.

Synthesis and characterization of sodium alginate-chitosan liposome gel beads via electrostatic complexation: A dual-network platform for co-delivery of folic acid and vitamin E.

Multifunctional bilayered nanofibrous scaffold of chitosan/poly(caprolactone) enriched with simvastatin and thymoquinone for accelerated diabetic wound healing.

High performance portable sensor based on excellent conductive composite MXene@Ag-MEL for detection of gallic acid in foods.

Evaluation of photodynamic therapy using indocyanine green loaded chitosan nanoparticles, as an adjunct to non-surgical periodontal therapy in patients with stage I and II periodontitis". A randomized controlled trial.

Electrical stimulation from electroactive bioma0terials is indispensable for peripheral nerve regeneration, but traditional invasive methods carry infection risks. Non-invasive techniques based on ultrasound and piezoelectric materials provide new solutions to this challenge. In this study, polydopamine (PDA) was used to surface-modify barium titanate nanoparticles (BTNPs), which were then combined with chitosan (CS) microcarriers to successfully fabricate composite microcarriers (BTNP@PDA/CS) with piezoelectric-conductive dual electroactivity for sciatic nerve defect repair. BTNP@PDA/CS piezoelectric microcarrier has good charge transfer ability and electrochemical stability. Under ultrasonic stimulation (US), it has good piezoelectric effect and ultrasonic response characteristics, and the output voltage can be controlled by the ultrasonic power. The results of cell experiment under in vitro ultrasonic electrical stimulation showed that it has a positive effect on promoting macrophage M2-type polarization and the elongation of PC12 cells. The results of animal experiments showed that the combination of piezoelectric microcarriers loaded with rBMSCs and US had anti-inflammatory effects on sciatic nerve defects in rats, accelerated nerve regeneration, and promoted the recovery of nerve motor and conduction functions as well as the recovery of nerve innervation target organs. In summary, the piezoelectric conductive microcarriers leverage ultrasound-driven in situ electrostimulation, offering a synergistic therapeutic strategy for nerve regeneration.

Rapid and pressure-free hemostasis combined with antimicrobial activity is highly desirable for emergency wound management, yet remains challenging to achieve using sustainable biomass-based materials. Herein, we report a multifunctional porous sponge constructed from chitosan (CS), sodium alginate (SA), and carboxymethyl cellulose (CMC) via a polyelectrolyte coupling strategy. By optimizing the CS/SA ratio and introducing CMC as a hydrogen-bonding reinforcement component, the resulting sponge exhibits an interconnected porous architecture, favorable mechanical resilience under wet conditions, and rapid fluid uptake. The synergistic integration of cationic CS and anionic polysaccharides enables strong blood cell and protein interactions, promoting efficient clot formation without external compression. Meanwhile, the intrinsic antibacterial activity arises from CS-induced bacterial membrane disruption combined with microenvironment modulation by the polysaccharide network. In vivo evaluation using a mouse liver hemorrhage model demonstrates rapid bleeding suppression and significantly reduced blood loss compared with conventional gauze, together with favorable tissue compatibility and accelerated wound healing behavior. This work provides a sustainable and facile strategy for designing biomass-derived hemostatic sponges that integrate rapid intrinsic hemostasis, antibacterial functionality, and biocompatibility, offering a promising platform for next-generation wound management materials.

Rice husk-derived silica nanoparticles (RSN-50) possess an inherently negative surface charge over a wide pH range, which limits their effectiveness for the removal of chemically diverse pollutants. To overcome this dominant charge limitation, an amphoteric polyelectrolyte scaffold (ACS-4B) composed of chitosan (CS), alginate (Alg), and biosilica was designed to enable pH-responsive surface charge regulation using complementary functional groups (-COOH, -NH3+, and -SiOH). ACS-4B demonstrated efficient adsorption of cationic dye (methylene blue, MB), anionic dye (Congo red, CR), and toxic metal ions (Pb2+ and Cr6+) across a wide pH range without pH adjustment. Mesoporous ACS-4B scaffolds with a specific surface area (233.2 m2/g) could achieve maximum adsorption capacity for MB (630 mg/g), CR (387 mg/g), Pb2+ (539 mg/g), and Cr6+ (585 mg/g) within 150 min at the inherent solution pH, indicating the pH-responsive amphoteric behavior of ACS-4B (CR (6.7), MB (5.9), Pb2+ (2.9), and Cr6+ (4.9)). The selective adsorption trends under mixed-pollutant conditions further reflect charge-adaptive interactions. ACS-4B retained its adsorption functionality over four consecutive regeneration cycles, indicating preliminary reusability. The combined amphoteric surface chemistry, inherent postadsorption pH-buffering ability, and biowaste-derived design highlight ACS-4B as a promising adsorbent for textile dye and metal-containing wastewater treatment.

ABSTRACT Chitosan (CS) is a widely distributed and abundant biopolymer in nature. In this study, CS was blended with poly(methacrylic acid) (PMAA) to prepare stable chitosan composite nanofibers (CS/PMAA) via electrospinning, followed by annealing. The nanofibers were then functionalized through Schiff base reactions between CS amino groups and aldehydes and used to support palladium catalysts. Their catalytic performance was evaluated by the Heck reactions. Notably, the Pd 2+ ions anchored on the CS/PMAA nanofibers exhibited higher activity than those on the 2‐pyridylimino‐functionalized chitosan nanofibers (2PyCS/PMAA). In contrast, the Pd 0 species supported on the 2PyCS/PMAA nanofibers showed outstanding catalytic activity and remarkable reusability. HR‐TEM was utilized to monitor the morphological changes and Pd 0 nanoparticle contents on the CS/PMAA and 2PyCS/PMAA nanofibers during reuse. Chelating interactions between the nanofibers and Pd 2+ ions were studied by FT‐IR, adsorption distribution analysis, XRD, and HR‐TEM. The strong nucleophilic affinity of Pd 2+ ions for the CS nanofibers was further verified by PALS. In conclusion, this work presents an effective and straightforward approach for preparing highly active and stable supported palladium catalysts.

Bio-based polymers are believed to often demonstrate insufficient barrier capacity and mechanical strength, especially in egg packaging processes. This current work attempted to improve the characteristics of chitosan (CS) films for egg packaging by incorporating cellulose nanocrystals (CNC) and sodium montmorillonite (MMT) nanoparticles. Such nanofillers added to the polymer matrix should reduce water vapor permeability and improve the mechanical properties of bio-nanocomposite films. Herein, coatings containing 5 wt% CNC or MMT incorporated into chitosan were applied to enhance the storability of fresh eggs over 5 weeks at ambient conditions. SEM images revealed that coatings were able to seal the eggshell pores, thereby minimizing mass transfer. After 5 weeks of storage, the Haugh unit (HU) of eggs treated with CS–CNC (67.1) and CS–MMT (64.8) appeared reasonably higher than that of control (35.2) and pure chitosan (52.1). The yolk index of eggs coated with CS–CNC (0.355) and CS–MMT (0.343) surpassed both control (0.263) and CS-coated eggs (0.308). However, pH levels in the albumen of eggs coated with CNC or MMT nanocomposite were significantly lower than others during storage. Potentially, chitosan-based nanocomposite coatings could be effective in preserving the internal quality of eggs, providing a somewhat efficient barrier against CO2 loss with relative pH maintenance.

We analyzed the effect of charge density (CD) on the phase behavior, viscoelasticity, and underwater adhesion of complex coacervates formed from high-molecular-weight, semi-flexible, bio-sourced polyelectrolytes. For this, hyaluronic acid (HA) was complexed with chitosan (CHI) of different degrees of deacetylation (DD) at pH 5.0. It was found that increasing CHI deacetylation enhanced macroion pairing, expanding the two-phase region of the phase diagram. Time-salt superposition (TSS) was successfully applied, allowing us to rescale the linear viscoelastic response of all the HA-CHI series onto individual master curves, indicating that the relaxation dynamics of all series are controlled by macroion pairing. The TSS curves were further collapsed onto a universal master curve via a so-called time-salt-charge density superposition (TSCDS). This first report of TSCDS for entangled complex coacervates revealed that the salt sensitivity of the dynamics depends on the charge density, which is in contrast with reports on flexible polyelectrolytes. It is proposed that this difference is due to the interplay between the persistence length of the semi-flexible polyelectrolytes and kinetic trapping in these entangled systems. The underwater adhesion strength (σmax) of HA-CHI reached 74 kPa at 0.2 M NaCl. Replacing CHI's acetyl moiety with a less polar butyryl group (but-CHI) at a given DD had a slight effect on the composition and viscoelastic properties. However, HA-but-CHI had the highest underwater adhesion near physiological salinity (σmax of 110 kPa and an adhesion energy of 18 J m-2), placing it among the most high-performing coacervate-based underwater adhesives without an external trigger.

Graphene oxide (GO)-based membranes are promising for sustainable water purification due to their sub-nanometer interlayer channels, which provide ultrafast water transport and high salt rejection. However, they generally exhibit limited structural stability in aqueous media, leading to increased interlayer spacing and reduced salt rejection. Here, the polysaccharide chitosan (CH) is introduced into the GO galleries through a one-pot pressure-assisted self-assembly method to stabilize the GO interlayer spacing at a specific distance. Furthermore, CH, as a positively charged polysaccharide, confers the membrane with local positive charges. These, in combination with the inherent negative charges on the GO surface, result in GO-based membranes possessing simultaneous size-sieving, cation recognition, and anion exclusion capability. The ratio of CH: GO was found as a key parameter, controlling the interlayer spacing, nanochannel total charge density, and cation charge density along the channel. The results showed that the membrane containing 0.02mg/cm2 GO and 0.15mg/cm2 CH exhibited superior rejection for MgSO4, NaCl, and MgCl2, alongside the highest water permeability due to the optimal interplay of size sieving, ion exclusion, and cation recognition mechanisms. The strong interactions between GO layers and CH chains via hydrogen bonding and electrostatic interactions significantly improved the structural stability of the membranes in various harsh environments. This work provides a new insight for designing sustainable GO-based membranes with both high ionic separation performance and water permeability through simultaneously utilizing size-sieving, ion exclusion, and cation recognition mechanisms.

In this study, the polymer nanocomposites (PNC) films, which consist of chitosan (CS), poly (vinyl) pyrrolidone (PVP), and iron vanadate (FeVO4) nanoparticles (FVO NPs) were prepared utilizing the solution casting method. Numerous investigations, including structural, vibrational, electrical, dielectric, and optical tests, demonstrate promising properties of the generated polymer nanocomposites. Up to a 1.5 weight% FVO concentration, the sample's amorphous character improved, according to the Xray diffraction (XRD) examination. The existence of intermolecular interactions in the nanocomposite was confirmed by Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy. Experimental results showed that the nanocomposites' optical bandgap decreased as the FVO concentration grew. The investigative values of the ε', ε'', and σac show notable differences in frequency. It is found that the values of the ε' and ε'' rise with frequency. It is shown that when the frequency increases, so does the σac. The σac value increased with frequency, reaching 4.14 × 10- 6 S·cm- 1 at 104 Hz from 5.42 × 10- 10 S·cm- 1 at 100Hz. An increase in σac values is observed when the loading of FVO NPs is increased. Dielectric analyses showed that the CS/PVP/1.2%FVO nanocomposite sample had the best boost. Additionally, the energy density rose from 4.2 × 10- 7 J/m3 for CS/PVP to 1.35 × 10- 6 J/m3 for CS/PVP/1.2%FVO. The results show that the CS/PVP/FVO films can be used in energy storage applications because of their dielectric properties, which are successfully improved by increasing the FVO concentration.

Stabilization of chitosan-based high internal phase emulsions via tannic acid-mediated physical crosslinking.