Search Results (227)

Sodium caseinate (SC)-stabilized emulsions are highly susceptible to flocculation and phase separation near the protein isoelectric point (pI), limiting their application in acidified food systems. In this study, high acyl gellan gum (HA) was introduced to construct pH-responsive protein–polysaccharide complexes to modulate the interfacial assembly and stability of SC emulsions. Results demonstrated that HA interacts with SC primarily through electrostatic attraction and multi-site hydrogen bonding. This interaction induces protein conformational rearrangement and, as evidenced by combined structural and computational analyses, facilitates the assembly of a denser, interconnected composite network. The formation of HA–SC complexes significantly enhanced interfacial adsorption, reduced oil–water interfacial tension. Rheological and microrheological analyses revealed the composite system formed an elasticity-dominated weak gel network, restricting droplet mobility and suppressing aggregation. Consequently, HA–SC emulsions exhibited markedly improved pH tolerance and physical stability compared to SC-only emulsions, particularly near the pI, evidenced by reduced droplet size, lower Turbiscan stability indices, and more homogeneous microstructures. Crucially, utilizing a well-defined mechanistic model of fixed HA and SC concentrations, this study quantitatively links molecular interactions, interfacial network reconstruction, and macroscopic emulsion stability across a broad pH continuum. Rank-correlation analysis of pH-resolved descriptors shows the molecular charge state co-varies monotonically with the interfacial network and macroscopic stability, and is inversely coupled to droplet mobility. These findings provide new insights into protein–polysaccharide interfacial engineering, establishing the essential physical-stability foundation for the future rational design of acid-tolerant food emulsions and functional delivery systems. Full article

Objectives: this study aimed to develop and optimize an intranasal delivery system for Eplerenone (EPL) by incorporating Eplerenone-loaded liposomes (Elip) into an in situ gel system (Elip-GG). The goal was to prolong the residence time of the drug in the nasal cavity and ensure sustained release. Methods: Elip and unloaded liposomes were prepared using the thin-film hydration method. Key formulation variables such as encapsulation efficiency (EE%), mean particle size (MPS), polydispersity index (PDI), and zeta potential (ZP) were optimized. The Elip was then incorporated into a gellan gum (GG) in situ gel to form Elip-GG. The Elip-GG formulation was evaluated based on parameters such as pH, viscosity, rheological behavior, mechanical properties, and in vitro release. Results: the optimal Elip formulation exhibited an EE of 86.3%, a mean particle size of 86.56 nm, a PDI of 0.29, and a ZP of −29.86 mV. The cumulative drug release from the Elip-GG formulation exceeded 93% after 2.5 h. The Elip-GG formulation significantly increased the sustained release of Eplerenone when administered intranasally, offering a promising alternative to oral and parenteral delivery methods for hydrophilic antihypertensive drugs. Full article

Background/Objectives: Tuberculosis treatment remains challenging due to the limited stability and side effects of conventional rifampicin formulations. This study aimed to synthesize and optimize mucoadhesive chitosan–gellan gum nanoparticles for improved rifampicin delivery. The novelty of this work was the introduction of ethanol into the synthesis process, which improved the solubility of rifampicin and contributed to the formation of nanoparticles with the desired physicochemical characteristics. Methods: Rifampicin-loaded chitosan–gellan gum nanoparticles were produced using the polyelectrolyte complex coacervation method. The polymer ratios, drug-to-polymer ratio, temperature and ethanol volume were the main factors that were optimized using the Taguchi method. The physicochemical properties, such as TGA, DSC and FTIR spectroscopy, were investigated. In addition, drug release, mucoadhesive properties and mycobacterial activity against the H37Rv strain of Mycobacterium tuberculosis were examined. Results: Optimization using the Taguchi method produced nanoparticles with a narrow particle distribution (PDI: 0.212 ± 0.021), a satisfactory average size (153 ± 3 nm) and stability against aggregation (zeta potential: 22.94 ± 1.30 mV). A study of the degree of rifampicin release from nanoparticles showed that the drug release is influenced by pH and has a prolonged effect. Drug-loaded nanoparticles exhibited increased mucoadhesion compared with the pure drug. The minimum inhibitory concentration of rifampicin in chitosan–gellan gum nanoparticles for the suppression of the H37RV strain of Mycobacterium tuberculosis was determined. Spectroscopic and thermal analyses confirmed the incorporation of rifampicin in the polymer matrix. Conclusions: The developed chitosan–gellan gum nanoparticles represent a promising mucoadhesive delivery system for rifampicin. The incorporation of ethanol and the use of Taguchi optimization provide an effective strategy for controlling nanoparticle properties and improving drug delivery performance. Full article

Proton exchange membrane fuel cells (PEMFCs) are among the most promising clean energy conversion technologies, offering high efficiency and zero emissions. However, their large-scale commercialisation is limited by the high cost and environmental impact of conventional perfluorosulfonic acid membranes such as Nafion. In recent years, increasing attention has been directed toward biopolymer-based membranes as sustainable, low-cost, and biodegradable alternatives. This review provides a comprehensive overview of recent advances in the development and modification of biopolymer membranes, including polysaccharide-based materials such as chitosan, cellulose, gellan gum, sodium alginate, and starch, as well as protein-based materials such as keratin and collagen. Various modification strategies, including sulfonation, phosphorylation, cross-linking, and incorporation of inorganic or hybrid fillers, are analysed for their impact on key parameters, including proton conductivity, methanol permeability, and power density. Comparative data indicate that several modified biopolymer membranes achieve proton conductivities of 50 mS/cm or higher. However, higher conductivity values are generally reported for membranes primarily composed of synthetic polymers, where the biopolymer is incorporated only as an additive. In addition, some biopolymer-based membranes exhibit significantly lower methanol permeability than Nafion. The lowest reported value among the membranes discussed in this article is 0.98 × 10⁻¹⁶, representing the best-performing biopolymer membrane in terms of methanol permeability alone. Although many biopolymer membranes demonstrate relatively poor performance in single PEMFC tests, several have achieved power densities comparable to Nafion, while simultaneously offering improved environmental compatibility and sustainability. Finally, current challenges and future directions are discussed, emphasising the potential of these renewable materials to advance PEMFC technology toward more sustainable and economically viable energy systems. Full article

While hydroxypropyl methylcellulose (HPMC) is a promising plant-based alternative to gelatin, its industrial application is limited by poor mechanical properties and high production costs. In this study, high-performance HPMC-based hard capsules were developed using an HPMC/gellan gum/ι-carrageenan ternary system. The formulation and preparation process were optimized via single-factor experiments, response surface methodology, and low-field nuclear magnetic resonance analysis. Scanning electron microscopy was applied to characterize the microstructural evolution during disintegration. The optimized capsules exhibited rapid disintegration within 15 min across four pH media and satisfied the requirements of the Chinese Pharmacopoeia (2025). Drug dissolution profiles using cefradine and ranitidine hydrochloride showed over 85% cumulative release within 30 min, with similarity factors higher than 50 relative to commercial gelatin capsules under the tested conditions. This work provides a feasible and low-cost strategy for the industrial production of plant-based capsules and promotes the high-value utilization of polysaccharide-based capsule materials. Full article

In recent years, nanotechnology has made remarkable progress in the fight against infectious diseases. However, the development of safe and effective antiviral drugs remains a challenge, as viruses rely on host cells for replication. Plant-derived, environmentally friendly nanoparticles have gained significant attention due to their low toxicity, which enables them to target viruses without damaging host cells. In this study, we describe the synthesis of silver nanoparticles (AgNPs) using Arctostaphylos uva-ursi leaf extract and explore their potential antiviral activity. The uva-ursi AgNPs were initially characterized using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). We then optimized two different gellan gum/alginate film formulations (1.6:0.4 and 1.2:0.8) as delivery matrices for the AgNPs and assessed Ag⁺ skin permeation using a Franz diffusion cell system. The antiviral potential of the uva-ursi AgNPs—both alone and incorporated into the films—was tested against herpes simplex virus type 1 (HSV-1). Our findings indicate that uva-ursi AgNPs may directly interact with the viral envelope, disrupting the lipid membrane and/or interfering with viral surface proteins. Overall, green-synthesized uva-ursi AgNPs may represent a natural, cost-effective, and safe alternative strategy for managing herpetic infections. Full article

The instability of pigments and non-quantitative indication limit the application of intelligent labels in food freshness monitoring. Natural anthocyanins face challenges including photodegradation and difficulty in quantifying shrimp freshness. To solve these problems, this study prepared a colorimetric intelligent label with UV-shielding and real-time monitoring functions. Carbon-coated nano-TiO₂ (C-TiO₂) was synthesized by the hydrothermal method and combined with blueberry anthocyanins (BAs) in an agarose (AG)/gellan gum (GG)/glycerol matrix. The label properties were characterized and a remaining shelf-life prediction model was established based on the correlation between label color difference (ΔE) and shrimp total volatile basic nitrogen (TVB-N). The results demonstrated that C-TiO₂ could enhance compatibility and color stability, and maintain mechanical properties. After 24 h of ultraviolet irradiation, the BA degradation rate was 98.4% in the GAB group and 62.8% in the GABT-0.05 group, representing a reduction of 35.6% compared to the former. This indicates that the addition of C-TiO₂ significantly enhanced photostability. The predictive model demonstrated an error below 10% at both 10 °C and 20 °C conditions, indicating its potential for shelf-life prediction applications. This dual-functional label provides a reliable method for visual and quantitative evaluation of shrimp freshness. Full article

This study aimed to manufacture and characterize highly porous dressings based on gellan gum (GG) and sodium alginate (Alg) hydrogels modified with zinc oxide (ZnO) and bacitracin (BAC) intended for infected and exuding wounds. ZnO nanoparticles (ZnO(n)) were 26 ± 4 nm in size according to atomic force microscopy (AFM), while the size of the microparticles (ZnO(m)) was 1.02 ± 0.01 µm according to laser diffraction measurements. Their relative surface areas were 39.16 m²/g and 4.56 m²/g, respectively. Microbiological studies showed that ZnO(n) exhibited antibacterial activity in contact with the Gram+ Staphylococcus aureus; thus, they were selected for embedding in a hydrogel matrix. Four types of composite hydrogel samples were manufactured: GG/Alg, GG/Alg+ZnO, GG/Alg+BAC, and GG/Alg+ZnO+BAC, which were subjected to freeze drying. The water absorption of all materials exceeded 4000%, showing excellent liquid absorbability. Burst release of BAC was found at a level of 90% in the first 2 h. In vitro cytotoxicity studies on L929 fibroblasts did not show a toxic effect of extracts from the GG/Alg and GG/Alg+BAC samples, contrary to samples supplemented with ZnO(n). In microbiological studies, the enhanced antibacterial effect of ZnO(n) and BAC was observed in contact with Staphylococcus aureus and Staphylococcus epidermidis strains. Therefore, GG/Alg+BAC+ZnO is the most promising dressing system for the treatment of infected and exuding wounds. Full article

The demand for sustainable food packaging is increasing. This study developed a novel ternary composite film based on gellan gum (GG), chitosan (CS), and melatonin (MT) for preserving fresh blueberries. For the first time, MT was incorporated as a functional agent into a GG/CS matrix. Films with varying compositions were prepared and characterized. The GG-dominant film with the highest MT content (G2C-M50, 2:1:0.5 w/w) exhibited optimal properties, including high tensile strength, enhanced flexibility, and a superior moisture barrier. In a 7-day storage trial, this film dramatically extended blueberry shelf-life, reducing the spoilage rate to 2.2% while maintaining 80.5% of the initial anthocyanin content. This success is attributed to the synergy between the robust GG/CS physical network and the multifunctional (antioxidant, antimicrobial) activities of MT. This work presents a highly effective strategy for active food packaging. Full article

In this work, gellan gum microspheres (G–MPs) were developed as delivery systems for blueberry extract (Vaccinium myrtillus) (BEX), a source of natural antioxidants rich in anthocyanins (ATCs) and phenolic compounds (PHCs). Gellan gum, an anionic polysaccharide produced via fermentation by Sphingomonas elodea, was selected for its biocompatibility and gelling properties. BEX was obtained using a mild citric acid–based extraction method to preserve antioxidant capacity and was characterized for its total polyphenol, flavonoid, and anthocyanin content before loading. The extract was loaded into gellan gum microspheres via absorption (G–MPs–BEX). The resulting microspheres exhibited a spherical and porous morphology that favoured both encapsulation and controlled release. FT–IR analysis confirmed the absorption of the extract within the polymer network and revealed hydrogen bonding interactions between the matrix and active compounds. Despite these interactions, microspheres retained a high swelling capacity and enabled rapid release, with maximum release of polyphenols and anthocyanins within 30 min at pH 5.5. The antioxidant activity of BEX, assessed via DPPH assay, remained stable during storage (up to 60 days) and after incorporation into the microspheres. Overall, this study demonstrates that G–MPs can efficiently absorb, stabilize, and release natural antioxidant compounds, supporting their potential use in biomedical, nutraceutical, and cosmetic applications. Full article

Wound-related inflammatory pain is a major contributor to wound healing success and requires wound-specific therapeutic platforms with minimal systemic adverse effects. This study builds a dual-crosslinked polyvinyl alcohol (PVOH)/carboxymethyl cellulose (CMC)/gellan gum hydrogel system with optimized mechanical strength and sustained anti-inflammatory drug delivery by developing predictive mathematical models using response surface methodology with central composite design. The effects of citric acid (5–15% w/w) and dialdehyde carboxymethyl cellulose (DCMC, 0.0125–0.0375% w/w) on mechanical properties were systematically evaluated. The optimal formulation (2.23 g low-acyl gellan gum, 1.00 g high-acyl gellan gum, 0.02% DCMC, 10.21% citric acid) achieved firmness of 1.27 ± 0.06 N, rupture strength of 24.24 ± 0.52 N, and compressive strength of 41.91 ± 0.62 kPa. Curcumin oil incorporation yielded 82% cumulative release over 360 min following Korsmeyer–Peppas kinetics (R² = 0.9887, n = 0.8773). Cell viability exceeded 70% throughout the release period, confirming biocompatibility. The hydrogel strongly inhibited reactive oxygen species (ROS) and nitric oxide (NO) production in lipopolysaccharide-stimulated macrophages (p < 0.001) and enhanced macrophage migration, increasing wound closure from 40–80% (p < 0.001). This dual-crosslinked hydrogel shows great potential for localized inflammatory pain relief. Full article

Meat products are prone to spoilage during storage and transportation due to the decomposition of amino acids and proteins, which generates volatile amines and elevates pH levels. In recent years, research on pH indicator labels for food has significantly increased. This study investigates a functional film with a bilayer structure for real-time freshness monitoring of meat. Utilizing Tara gum (TG) and Gellan gum (GG) as the base material and nanocellulose composite GG/blueberry anthocyanins as the sensing layer, titanium dioxide was incorporated to effectively block ultraviolet radiation. Through response surface methodology, the cellulose nanocrystals (CNCs) preparation process was optimized to address issues such as insufficient mechanical properties, hydrophobicity, and thermal stability of the composite film. Results showed that the composite film achieved optimal performance when CNC content was 6%. This research provides a simple and effective solution for real-time freshness monitoring of meat products, offering advantages such as low cost, environmental friendliness, and user-friendly operation. Full article

The physiological relevance of in vitro models is limited because conventional two-dimensional cell culture systems are unable to replicate the structural and functional complexity of native tissues. Extracellular matrix (ECM)-mimetic hydrogels have become important platforms for tissue engineering applications. This work developed hybrid hydrogels that mimic important biochemical and mechanical characteristics of cardiac tissue by combining decellularized bovine pericardium-derived (dBP) ECM, gellan gum (GG), and spermine (SPM). Although dBP offers tissue-specific biological cues, processing compromises its mechanical integrity. This limitation was overcome by adding GG, whose ionic gelation properties were optimized using DMEM and SPM. The hydrogels’ mechanical, biological, physicochemical, and structural characteristics were all evaluated. Under physiologically simulated conditions, the formulations showed quick gelation and long-term stability; scanning electron microscopy revealed an interconnected, ECM-like porous microarchitecture. While uniaxial compression testing provided Young’s modulus values comparable to native myocardium, rheological analysis revealed a concentration-dependent increase in storage modulus with increasing SPM content. H9C2 cardiomyoblasts were used in cytocompatibility studies to confirm that cell viability, morphology, and cytoskeletal organization were all preserved. All of these findings support the potential application of dBP−GG−SPM hydrogels in advanced in vitro cardiac models by showing that they successfully replicate important characteristics of cardiac ECM. Full article

The growing global production of plastic, which reached 460 million tonnes in 2022 and has projections of 5.4 million tonnes of waste by 2050 without intervention, has created a severe environmental crisis that demands the development of sustainable alternatives. In this context, this study aims to characterise biodegradable films based on cassava starch and gellan gum, combining microstructural and mechanical properties with the evaluation of thermo-optical parameters. An important advance was the pioneering application of a self-normalised photoacoustic technique, used for the first time to measure thermal diffusivity (0.0013 ± 0.0002 cm²/s) and optical absorption coefficients (at 660 nm) as a function of different concentrations of aniline blue. The results validate the material, which showed high solubility (89.23 ± 1.03%) and crystallinity of 27.40 ± 1.68%. The film demonstrated remarkable biodegradability, losing almost all of its weight (98.30 ± 1.01%) in just 15 days. The measurement of the optical absorption coefficients (at 660 nm) confirmed a linear relationship with the concentration of aniline, validating Beer–Lambert’s law and providing the absorptivity of the dye within the solid matrix—something inaccessible with conventional methods. In conclusion, these films offer significant potential as a viable ecological substitute for single-use plastics, contributing significantly to mitigating the global impact of plastic waste. Full article

Cannabidiol (CBD), the primary bioactive element of cannabis, has shown promise in alleviating pain and inflammation, although mechanisms in periodontal inflammation are not fully understood. To improve its limited solubility and mucosal permeability, the developed chitosan-based mucoadhesive hydrogel incorporating CBD-loaded PLGA nanospheres (CPN hydrogel) was characterized by FT-IR, SEM, particle size, rheological, swelling, and diffusion analyses, followed by biological evaluations, including wound-healing and RT-qPCR-based anti-inflammatory assays. The improved CPN hydrogel had a homogeneous shape, better viscoelastic behavior, and sustained drug release. Over 90% of CBD was released within 96 h, and Franz cell experiments showed improved permeability (124.1 μg/cm² after 72 h). The gellan gum-based mucosal substrate significantly increased adhesion (1137.33 ± 142.25 s) compared to the control groups. Antioxidant studies indicated 73.65% DPPH radical scavenging, whereas antibacterial tests showed more than 99% suppression of Staphylococcus aureus. Furthermore, in vitro studies validated its wound healing and the downregulation of the inflammatory cytokines IL-6 and TNF-α. The results indicate that the CPN-loaded chitosan hydrogel has extended mucosal retention, strong antibacterial activity, and steady release of CBD. This underscores its significant potential as a targeted treatment for inflammatory oral diseases such as gingivitis and periodontitis. Full article