Search Results (2,121)

Chitosan nanoparticles (Ch NPs) are versatile nanomaterials with expanding agricultural and biomedical applications, highlighting the need for reproducible, low-cost, and scalable synthesis methods to ensure their safe and widespread use in biological systems. This study presents a simple ionic-gelation protocol using a serological pipette–needle dropwise system that minimizes reagent waste and requires no sophisticated equipment. The synthesized Ch NPs were characterized by UV–Vis spectroscopy, ESEM, TEM, EDS, DLS, XRD, and FTIR, confirming nanoscale size, strong positive surface charge, and characteristic chitosan–TPP interactions. To establish a standardized biological safety assessment framework, three representative bioassays were implemented across microbial, plant, and mammalian systems. Antibacterial testing against Xanthomonas oryzae pv. oryzae (Xoo) using a resazurin-based microdilution assay revealed a minimum inhibitory concentration (MIC) of 128 µg/mL, whereas bulk chitosan showed no inhibition up to 512 µg/mL. Phytotoxicity and seed germination assays on rice (Oryza ‘KDML105’) demonstrated no inhibitory effects on germination, with over 90% germination by day 3 and significantly enhanced seedling growth parameters (p < 0.05) at 64–128 µg/mL, indicating non-phytotoxicity. MTT assays confirmed that Ch NPs were non-toxic to both human skin cell lines (HDF and HaCaT) across 2.5–160 µg/mL, showing enhanced cell viability in HDF cells at specific concentrations and stable viability in HaCaT cells, indicating overall biocompatibility. Importantly, all bioassays were conducted under aligned concentration ranges to enable cross-system comparison and reproducibility. This integrated workflow links nanoparticle synthesis with a standardized, multi-system evaluation strategy, supporting the safe application of Ch NPs in biological systems. 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

This study presents a risk assessment of asphaltene–resin–paraffin deposition (ARPD) in the producing formations of the XIII reservoir unit of the Uzen oil field at a late stage of development. The crude oil is characterized by an extremely high paraffin (wax) content of up to 29 wt.%. Long-term operation of the reservoir pressure maintenance (RPM) system with cold water injection has resulted in significant reservoir cooling, with temperatures declining from the initial 60–65 °C to 20–30 °C in zones of intensive waterflooding. To refine the critical phase transition temperatures of paraffin components, a dynamic laboratory approach was applied using a Wax Flow Loop system, which simulates wax deposition processes under flowing conditions. The results indicate that the wax appearance temperature (WAT) ranges from 41.0 to 44.0 °C, significantly exceeding the current bottomhole temperatures in the cooled zones of the reservoir. Intensive bulk crystallization of paraffins occurs within the temperature interval of 33.5–35.0 °C, while loss of oil flowability is observed at 25–34 °C, corresponding to the gelation and structural network formation of wax crystals under reduced thermal conditions. The obtained results confirm the inevitability of bulk oil structuring and solid wax phase precipitation directly within the reservoir porous medium. This process leads to blockage of low-permeability interlayers, deterioration of filtration properties, and a reduction in the displacement efficiency factor by 20–35%. Under the current thermal regime, ARPD should therefore be considered not merely as an operational flow assurance issue, but as a systemic factor limiting reservoir development efficiency. The research results substantiate the need to transition from reactive ARPD removal methods to proactive management of the thermal regime of the reservoir and wells, as well as to the differentiated application of thermal and chemical treatment methods. Full article

Soy protein concentrate (SPC) undergoes continuous thermal and structural changes during passage through a cooling die, yet these changes are often interpreted using viscosity-based descriptions that do not explicitly account for structural development rate (SDR). This study developed a rheology-guided framework to analyze SPC behavior in a three-stage cooling die by integrating isothermal and non-isothermal rheological characterization with computational fluid dynamics (CFD). SPC samples containing 76, 78, and 80% moisture were evaluated using strain sweep, frequency sweep, viscosity, time sweep, and temperature sweep tests. Lower moisture promoted stronger structure development, higher viscosity, and faster gelation. For the 76% moisture sample, peak SDR increased from 6.66 Pa/s at 50 °C to 22.46 Pa/s at 100 °C, while the time to peak decreased from 937 to 360 s. During non-isothermal cooling, the major structure development occurred in the 80–50 °C interval, where ΔG′ reached 4902.54 Pa at 76% moisture. CFD analysis showed that the gelation-kinetics-based model predicted both pressure and extrudate temperature more accurately than the viscosity-based model. Pressure RMSE ranged from 8.57 to 14.43 kPa for the kinetic model, compared with 11.31 to 22.39 kPa for the viscosity model. These results demonstrate that the three-stage cooling die should be interpreted as a coupled thermal, flow, and structure-development domain. Full article

Supramolecular oleogel lubricants construct a three-dimensional network structure within base oils through gelator-mediated non-covalent interactions, such as hydrogen bonding, van der Waals forces, and π–π stacking. These materials demonstrate unique advantages in mitigating issues inherent to traditional lubricants, including leakage, volatility, creep, and poor heat dissipation. Focusing on structural design and performance regulation, this review systematically summarizes the current development of supramolecular oleogel lubricants in the fields of green lubrication, extreme operating conditions, and nanocomposite lubrication. Specifically, it outlines the structure-property relationships between gelators and base oils in green lubrication systems, and elucidates the applications in radiation-resistant, high-load-bearing, and intelligently responsive lubrication. Strategies for utilizing nanocomposite supramolecular oleogels to resolve nanomaterial dispersion challenges are discussed, and the latest advancements in engineering applications are illustrated. By summarizing the development of supramolecular oleogel materials, this work can provide theoretical references for the future design and preparation of these lubricants. Full article

The development of new advanced functional materials from low-molecular-weight gelators and their new potential applications have occupied a considerable place in research. The present study involves the design of dipeptide-based organogelators with enhanced hydrogen bonding network potentials and phase-selective capacities, possessing a minimum gelation concentration of 0.2–0.4% w/v in different fluids. Seven new dipeptide organogelators were prepared based on a one-step reaction from two-component salt forms, the combination of Nε-alkanoyl-L-lysine ethyl ester with N-alkanoyl-L-amino acids (L-alanine, L-leucine, and L-phenylalanine), with high yields of up to 90. All the gel materials were extremely stable at room temperature, having a shelf life of several months, and formed gels in pharmaceutical fluids such as ethyl palmitate, ethyl myristate, and ethyl laurate, 1,2-propanediol, and liquid paraffin (oils widely used in pharmaceutical formulations), which meet the criteria of biological materials delivery. Their gelation properties were evaluated by rheological measurements. A very significant breakthrough in the current study is that organogels remove the toxic dye, crystal violet (CV), from water in a phase-selective manner with an extremely low gelator concentration. The dye and gelators are successively recovered via ethanol precipitation after the completion of the phase extraction process. Molecular dynamic calculations provide evidence for the 3D structures of the gels. Full article

The rapid expansion of edible insect production has focused primarily on rearing, processing efficiency, safety, and nutritional composition, while the slaughter of insects has received comparatively little scientific and ethical scrutiny. This narrative review examines insect slaughter as a critical control point linking bioethics, physiology, and ingredient quality. The review synthesizes evidence from neurobiology, food science, and processing studies to evaluate how commonly used slaughter methods interact with biological aspects of insects. Existing literature shows that slaughter techniques influence protein stability and hydrolysis, lipid oxidation, antioxidant retention, techno-functional properties such as emulsification and gelation, as well as sensory attributes and consumer acceptance. Available evidence suggests that methods designed to rapidly suppress metabolic activity may be associated with improved preservation of certain nutritional and functional parameters, although findings remain species- and context-dependent. The review further highlights major knowledge gaps, including the lack of species- and life-stage-specific welfare indicators and standardized assessment protocols. Overall, the findings support the need to reconceptualize insect slaughter as a strategic upstream decision rather than a neutral processing step. Integrating ethical considerations with nutritional, functional, and regulatory perspectives is essential for establishing science-based standards and ensuring the responsible development of edible insect-based food and feed systems. Full article

Soybean (Glycine max L. Merr.) is one of the most important legume crops globally, providing high-quality plant protein and oil for humans and livestock, and playing a crucial role in nitrogen fixation within agricultural ecosystems. The seeds contain about 35–40% protein by dry weight, with 65–80% of this being seed storage proteins (SSPs). These proteins mainly consist of 11S globulin (glycinin) and 7S β-conglycinin, which accumulate significantly in protein bodies during seed development, providing essential nitrogen and amino acids for seed germination and early seedling growth. Additionally, the composition and structure of SSPs directly determine the nutritional value, processing functionalities (such as emulsification, gelation, and solubility), and potential allergenicity of soybean products. In this study, we conducted a detailed analysis of the structural characteristics, chromosomal localization, phylogenetic relationships, and tissue expression patterns of members of the soybean Gy gene family, laying a theoretical foundation for further exploration of the biological functions of Gy genes in soybeans. We performed comprehensive genomic identification, expression analysis, and subcellular localization of the soybean Gy gene family. The results showed that the seven soybean Gy genes are unevenly distributed across different chromosomes and exhibit distinct expression patterns in soybean seeds, suggesting they may have different roles during seed development. Subcellular localization experiments indicated that the GmGy1 gene might play an important role during seed development. These findings provide significant insights into the functions of the Gy gene family in soybean growth and development and offer potential candidate gene targets for soybean molecular breeding. Full article

As demand for sustainable plant protein rises, pumpkin seeds emerge as a promising but underutilized source. Conventional alkaline extraction (ALK) often impairs protein functionality, prompting interest in non-thermal alternatives. This study systematically compared the functional, colloidal, and structural properties of pumpkin seed protein isolates obtained via ALK (conducted at 50 °C), ultrasound-assisted (UAE), and microwave-assisted extraction (MAE). UAE produced the highest extraction yield (50.07%), superior overall solubility, greatest water and fat absorption capacities, and lowest least gelation concentration (12%). Furthermore, UAE best preserved native protein secondary structure (retaining 43.45% alpha-helix), as quantified by FTIR peak deconvolution, and maintained an intact, flake-like morphology under scanning electron microscopy (SEM), yielding the most uniform particle size distribution. Conversely, MAE achieved the highest protein content (73.53%) and the most negative zeta potential, leading to the highest emulsifying and foaming capacities despite inducing a bimodal particle size and irregular, porous surface morphology. ALK performed the poorest across structural and functional metrics, severely denaturing the proteins due to combined alkaline and thermal stress. UAE is recommended for applications requiring optimal solubility and gelation, whereas MAE is highly effective for emulsion- and foam-based food systems, reinforcing pumpkin seeds as a viable sustainable protein ingredient. Full article

The management of waste bentonite slurry (WBS) produced during slurry shield TBM excavation involves environmental and operational challenges from the perspective of developing a more sustainable tunnelling construction process. In this study, the potential reuse of WBS as a complete replacement for bentonite in two-component grout formulations used for TBM backfilling is explored. A comprehensive laboratory testing program is conducted, in which the effects of WBS on the properties of two-component grout (unit weight, viscosity, bleeding, gel time, and mechanical strength) are assessed after various curing times, and the outcomes are compared with standard values commonly given in technical specifications. WBS produced from two different commercial bentonites is investigated. The results show that while the first formulation exhibits rapid setting and irregular gelation, the mix derived from the second bentonite demonstrates superior mechanical performance, increasing compressive strength by up to 40%. This enhancement is primarily governed by a physical filler effect, where fine soil particles optimize packing density and refine the microstructure. Consequently, the incorporation of selected types of WBS into a two-component grout could be a practicable approach, since it offers benefits in terms of mechanical performance, although careful mix design would be required to manage workability. This study shows how tunnelling can become more sustainable by reusing excavation waste and transforming it into a useful by-product. Full article

Formaldehyde emissions from urea–formaldehyde (UF)-bonded particleboards remain a significant environmental and health concern. This study evaluates the effectiveness of flours as bio-based formaldehyde scavengers in particleboard production. Food-based flours (soy, wheat, green pea) and feed flours (hemp, maize DDGS, feather meal) were incorporated into UF resin at concentrations of 0.3–2.0%. Resin characterization included pH, viscosity, gelation time, solid content, and free formaldehyde, while rheological behavior was monitored at 70 °C and 90 °C. The addition of flour decreased pH from 9.1 to 7.9 and increased viscosity from 414 to up to 1600 cP, depending on flour type and dosage. Free-formaldehyde content was reduced from 0.17% to as low as 0.08%, with the most effective reduction observed for hemp flour. At industrial scale, particleboards produced with 0.5% soy and hemp flours significantly reduced free formaldehyde, with emission values of 3.26 mg/m² and 3.05 mg/m², corresponding to reductions of 66–70% compared to the reference (3.97 mg/m²). Mechanical properties, including density (652–665 kg·m⁻³), bending strength (13.2–14.1 N·mm⁻²), and internal bond (0.42–0.45 N·mm⁻²), were maintained within acceptable limits. While feed flours such as feather meal showed strong scavenging potential, they caused significant viscosity increases (up to 1800 cP), limiting processability. These findings demonstrate that adding low levels of flour, particularly soy or hemp, is an effective, renewable, and low-cost strategy to reduce formaldehyde emissions in UF-bonded particleboards, supporting the production of safer and more sustainable wood-based composites. Full article

Background: In this study, type B gelatin was extracted from Oreochromis niloticus scales under hydrothermal conditions at 60 °C to evaluate the effect of ultrasound-assisted pretreatment on its structural, physicochemical, thermal, and functional properties. Methods: Gelatin obtained with and without ultrasound pretreatment was systematically characterized through molecular weight analysis, proteomic profiling, size determination, surface morphology, proximate composition, thermal behavior, and gelation-related functional properties in order to assess the influence of the extraction method on gelation performance. Results: Ultrasound pretreatment slightly increased gelatin yield from 1.46 to 1.70%, indicating enhanced collagen solubilization. Proteomic analysis confirmed the predominance of fibrillar collagen proteins in both samples, although differences in protein distribution were observed. Furthermore, weight-average molecular weight analysis revealed a reduction from 212.3 ± 11.8 to 170.9 ± 13.2 kDa in the ultrasound-treated sample, suggesting partial fragmentation of collagen chains induced by cavitation effects. Structural modifications were also reflected in increased porosity and surface changes, contributing to improved colloidal stability. However, these changes significantly affect the functional behavior of the gelatin. Ultrasound-treated sample exhibited limited gel-forming capacity and failed to form stable gels at the evaluated concentration, despite complete dissolution. In contrast, gelatin extracted without ultrasound treatment retained higher-molecular-weight fractions and formed stable gels at both 5 and 10% (w/w). Thermal and spectroscopic analyses suggested that the fundamental collagen structure was preserved in both samples, although differences were observed in thermal degradation behavior. Conclusions: These results highlight the importance of controlling ultrasound-assisted extraction conditions to balance collagen recovery with the preservation of molecular integrity required for gelation, providing insights for the development of sustainable fish-derived biomaterials for pharmaceuticals and biomedical applications. 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

Inspired by their biocompatibility and thermoreversible gelation—transitioning from room temperature liquids to body temperature gels—Pluronic hydrogels were employed in this study to optimize intracanal penetration and ensure medicament stability. We developed a silver nanoparticle (AgNP)-loaded Pluronic gel (AgNPs-P-gel) as a biocompatible, easily removable intracanal medicament. Following PRILE 2021 guidelines, AgNPs-P-gels (F127/F68) were evaluated for gelation, AgNP release, and antibacterial activity against Enterococcus faecalis and Streptococcus mutans via minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and growth curves. Biofilms in bovine teeth were quantified using CFUs and scanning electron microscope (SEM) imaging. Biocompatibility was tested in L-929 fibroblasts using MTT assays and RT-qPCR for pro-inflammatory cytokines (IL-6, TNF-α, IL-1β). Removal efficacy from bovine canals was microscopically scored. The optimized formulation (20% F127, 7.5% F68) gelled at 34 °C with sustained release over 168 h. AgNPs-P-gel showed strong antibacterial activity (MIC: 25–50 µg/mL). In ex vivo models, 100 µg/mL AgNPs-P-gel (AgNPs-100-P-gel) reduced bacterial counts comparably to calcium hydroxide and chlorhexidine, but with lower cytotoxicity. Although inducing cytokine expression similar to conventional medicaments, AgNPs-P-gel demonstrated significantly superior removability. Thermoreversible AgNPs-P-gel offers sustained antimicrobial action, favorable biocompatibility, and superior removability, potentially improving endodontic disinfection predictability as a calcium hydroxide alternative. Full article