Search Results (161)

Conventional microsphere drug carriers for ulcerative colitis (UC) face challenges such as limited residence time, variable drug release, and an increased risk of systemic exposure and side effects. In this study, pH-sensitive, core–shell hydrogel microcapsules were designed and fabricated using a BUCHI B-390 microsphere preparation device via electrostatic interactions and hydrogen bonds. Olsalazine sodium was encapsulated in the microcapsules, allowing for pH-responsive drug release in colon tissue for UC treatment in mice. XRD studies demonstrated the amorphous state of the drug in the formulation. The preparation of SCO microcapsules was optimized based on the drug encapsulation efficiency and the drug loading capacity, with the S₂C₁O microcapsule having the highest drug encapsulation efficiency (59.2%) and drug loading capacity (21.3%), and the production yield was approximately 62.5%. The degradation experiment results indicated that the alginate/CMCS hydrogel shell has anti-resistant and colon-targeted properties, with minimal drug leakage under acidic conditions (0.1% release at 2 h, pH 1.2) and rapid, controlled release at colonic pH (7.4) (cumulative release of 68.7% at 12 h), protecting the drug from gastric degradation. An in vivo experiment suggested that treatment with these microcapsules in UC mice significantly reduced inflammatory markers (NF-κB p65 was reduced by 18.8% relative to the free drug group) and histological damage in UC models relative to free drug administration. The improved therapeutic efficacy is linked to precise localization in inflamed tissue, reducing systemic exposure and off-target effects. Overall, in vitro and in vivo studies demonstrated that this microcapsule system provides a promising alternative to existing UC drug delivery systems. Full article

Goose bone paste is an underutilised poultry-processing by-product and a potential source of taste-active peptides. A nominal 1–3 kDa peptide fraction (F2), operationally designated an umami peptide fraction by analogy with comparable bone-hydrolysate fractions reported in the literature, was isolated from a neutral-protease hydrolysate by sequential ultrafiltration and encapsulated in sodium alginate (SA) microcapsules using extrusion–dripping ionic gelation. Single-factor screening identified the following formulation conditions: 2.0% (w/v) SA, 2.5% (w/v) CaCl₂, 0.3% (w/v) SE-15, a core-to-wall mass ratio of 0.3, and a preparation temperature of 50 °C. A verification batch prepared under these conditions gave an encapsulation efficiency of 75.44%, with the ±1.07% denoting the SD of three technical determinations from that batch. The dried microcapsules had a moisture content of 2.98 ± 0.21% and passable flowability. The mean particle diameter was 856 ± 52 μm, with a within-batch coefficient of variation of 5.56 ± 0.28%; a complete particle-size distribution was not recorded. In pepsin-free simplified simulated gastric fluid, the apparent release from the microcapsules rose from about 6% at 1 h to about 13% at 5 h, whereas the apparent detection ratio of free F2 rose from about 56% to about 99%. The calculated concentrations fell at or below the validated limit of quantification, the microcapsule-group absorbances lay near the photometric floor of the instrument, and only three sampling times were used. These percentages and the kinetic fits are therefore qualitative to semi-quantitative. The data support only the relative statement that alginate encapsulation lowered the apparent release of F2 under the tested acidic conditions. They do not establish an exact release rate, an error estimate for the microcapsule group, or a specific release mechanism. Full article

Background/Objectives: Natural clinoptilolite–amoxicillin hybrids (CNZ@AMOX) were incorporated into alginate microcapsules via ionic gelation to develop a hybrid mineral–polymer delivery system for the controlled release of amoxicillin. Methods: A face-centered central composite design combined with response surface methodology (FCCD-RSM) was utilized to assess the effects of the zeolite/sodium alginate ratio, alginate concentration, calcium chloride concentration and curing time on the encapsulation efficiency (EE), sphericity factor (SF), and roundness (Rn). Results: The EE ranged from 5.9% to 91.3%, depending on the formulation composition. Numerical optimization identified the optimal conditions as 70.962% EE, 0.05 SF and 1.00 Rn, with a desirability score of 0.873. The incorporation of natural clinoptilolite improved microcapsule structural integrity and reduced the initial burst release by modulating diffusion pathways within the hybrid matrix. The optimized CNZ@AMOX exhibited pH-dependent release behavior, with minimal drug release in simulated gastric fluid (SGF) and diffusion-controlled release in simulated intestinal fluid (SIF), which was best described by the Korsmeyer–Peppas model. Conclusions: These findings demonstrate that zeolite–alginate hybrid microcapsules represent promising inorganic–organic composite carriers for the pH-responsive and controlled delivery of AMOX. Full article

Intelligent food packaging (IFP) is among the key technologies for overcoming global challenges of food safety and food resource waste. Its core lies in monitoring the quality of food in real-time without damage. Sodium alginate (SA), a natural polysaccharide characterized by biodegradability and excellent biocompatibility, can form hydrogels with a 3D network structure, high water content, and functional modification capability, making it an ideal matrix for developing IFP sensing and indicator platforms. Based on the gel chemistry fundamentals of SA, this paper deeply analyzes the structure-activity relationship between sensing mechanism and material structure, and summarizes the existing modification strategies and functional integration paths. The paper also provides a detailed discussion on the application principles and latest advancements of SA-based hydrogels in colorimetric/visual sensing, gas sensing, time-temperature indicator (TTI), and controlled-release carriers for active substances. The current research results show that the detection limit of SA hydrogel beads loaded with anthocyanins for volatile amines can reach 15–25 ppm, and the color difference ΔE can reach 34.2 after 7 days of storage at 4 °C, which is strongly correlated with microbial indicators, total volatile basic nitrogen (TVB-N), pH, etc. The color difference value (ΔE) response of Co-Imd microcrystalline functionalized SA film to ammonia gas reached 23.7 within 60 min, and it had antibacterial activity. The activation energy of Immobilization of laccase on sodium alginate/soluble starch microcapsules to develop a TTI (27.32–61.13 kJ/mol) was highly matched with the activation energy of Agaricus bisporus. The hydrogel microspheres loaded with Cur@Se reduced the total oxidation value of the oils by 53%. The G/SA/nZnOs cryogel pad extended the shelf life of shrimp from 4 days to 6 days at 4 °C. In addition, this paper also discusses the challenges faced by SA-based hydrogels in large-scale production and long-term stability evaluation, and looks forward to future development trends such as integration with artificial intelligence (AI), Internet of Things (IoT), and multi-functional integration, in order to provide theoretical support for in-depth research and industrial application in this field. Full article

The aim of this study was to evaluate the effect of matrix type and dose of polyphenolic core from rose petals on the physicochemical and functional properties of microcapsules. Microcapsules were obtained by ionotropic gelation using four carrier systems: sodium alginate (SA), sodium alginate with added starch (SA + S), protein isolate (SA + P), and vegetable gum (SA + G). Polyphenolic compounds isolated from rose petals (E) were used as the core at six concentrations (0.25, 0.5, 1.0, 1.5, 2.0, and 2.5%). Differences between microcapsules were assessed based on physicochemical properties, polyphenol and anthocyanin content, antioxidant activity, swelling index, and biocompatibility. The results showed that both the extract dose and the matrix system significantly affected the analyzed parameters. The highest encapsulation efficiency was demonstrated for the lowest dose (0.25%), regardless of the matrix used. Total polyphenol and anthocyanin content significantly increased for all microcapsule versions with increasing extract dose, with the highest concentrations obtained for the SA + G system. These results strongly correlated with antioxidant activity and biocompatibility with human colonocyte membranes. In turn, the swelling index decreased with extract dose, showing the highest values in small intestinal fluid and the lowest in gastric fluid. These findings may have significant implications for the design of functional carriers for use in food and dietary supplement production. Full article

During thermal processing of the beech mushroom, water-soluble bitterness-related compounds migrate into the cooking liquor. Spermidine (SPD), one of the representative hydrophilic polyamines, has potential nutritional value, but its direct exposure may also contribute to bitterness. To improve its utilization while limiting the direct exposure of SPD, SPD recovered from beech mushroom cooking liquor was used as the core material to prepare soy protein isolate–dextran (SPI–Dex)/sodium alginate (SA) external gelation water-in-oil-in-water (W/O/W) emulsion and freeze-dried microcapsules. The study evaluated SPD recovery, emulsion stability, and the structural and encapsulation properties of the resulting microcapsules. The initial SPD concentration in the cooking liquor was 69.17 mg/L and increased to 520.10 mg/L after membrane filtration, low-temperature concentration, and food-grade enrichment, with an overall recovery of 72.16%. The emulsions showed a typical W/O/W multiple structure, with encapsulation efficiency (EE) and retention efficiency (RE) of 92.90–99.76% and 92.47–96.87%, respectively. SA improved emulsion structure, interfacial charge, and physical stability. After freeze-drying, the microcapsules showed a porous network structure, low water activity (0.2139–0.2279), and low moisture content (2.14–2.88%), with EE of 56.44–98.13% and RE of 70.21–89.12%. These results show that the SPI–Dex/SA system can effectively encapsulate and stabilize beech mushroom-derived SPD, and may provide a feasible strategy for limiting its direct exposure in food systems while improving the utilization of thermal processing by-products. 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

Cell encapsulation within semipermeable membranes is a promising strategy for protecting transplanted cells from host immune responses, while permitting the diffusion of nutrients and therapeutic molecules. Although alginate-based microcapsules are commonly used, ionically crosslinked capsules often exhibit limited structural stability and tunability in terms of membrane permeability. In this study, we developed covalently stabilized microcapsules. Alginate microgel beads were first prepared as sacrificial templates and subsequently coated with phenol-modified chitosan and hyaluronic acid (Chitosan–Ph and HA-Ph) via layer-by-layer assembly. The multilayer membrane was then covalently stabilized through horseradish peroxidase (HRP)-mediated oxidative coupling of phenol groups, followed by liquefaction of the alginate core. The crosslinked microcapsules maintained structural integrity after liquefaction, while markedly reducing γ-globulin permeation under in vitro conditions and preserving β-cell viability and glucose responsiveness. The findings of this study demonstrate the feasibility of this system as an in vitro platform for stable cell encapsulation, with potential relevance to cell therapy. Full article

Chlorothalonil is a widely used fungicide in agriculture, but its excessive application can lead to environmental contamination. This study investigated the biodegradation potential of Proteus terrae ZQ02 in free and immobilized forms. Under optimal conditions (37 °C, pH 7), free cells degraded 97.2–98.7% of chlorothalonil (50 mg/L) within seven days. Bacterial microcapsules were prepared using 3% sodium alginate, 2% calcium chloride, and 60 g/L wet biomass, with encapsulation times ranging from 6 to 12 h. The microcapsules displayed uniform size, high mechanical strength, porous structure, and excellent mass transfer, ensuring stable degradation activity. Encapsulated cells demonstrate enhanced tolerance to variations in pH, temperature, and salinity compared to free cells. In soil, microcapsules reduced chlorothalonil half-lives to 1.33–5.45 days for concentrations of 10–30 mg/L, achieving 92–96% degradation over 14–35 days. In tomato-planted soils, encapsulated and free cells degraded 96.3% and 81.6% of residues, respectively, after 28 days, significantly exceeding the control. These findings highlight that immobilization improves the stability, reusability, and efficiency of P. terrae ZQ02, making it a promising strategy for sustainable chlorothalonil biodegradation. The study demonstrates the potential of combining microbial strains with carrier materials for effective pesticide remediation and environmental protection, providing a foundation for large-scale applications in contaminated agroecosystems. Full article

This study investigates the fabrication of microcapsules using Nigella sativa (N.S.) oil as the core and alginate as the shell material. The N.S. oil microcapsules were prepared using the sol–gel method with different oil concentrations. The microcapsules were applied to the cotton fabric by the pad–dry–cure method, and their attachment was evidenced by scanning electron microscopy (SEM). Air permeability measurements were conducted for all developed samples, revealing that the sample with 8 g loading of N.S. oil and 4.5 g alginate exhibited a 43% reduction compared to the pristine sample. To further investigate the comfort characteristics of the samples, the functionalized cotton samples were subjected to the water vapor permeability index test. The results yielded an index value of 90, indicating that the encapsulation process preserved the comfort characteristics of the samples. Among the samples, the specimen with an oil concentration of 8 mL displayed the maximum antibacterial performance, achieving a 90% reduction in colony-forming units (CFUs) following quantitative testing protocol. However, the qualitative antibacterial assessment indicates no clear zone of inhibition, but no bacterial growth was observed on the samples. Furthermore, the fabric incorporating the maximum loadings of N.S. oil and alginate capsules exhibited the maximum antioxidant activity of 86.5%. These results underscore the critical role of N.S. oil microcapsules in enhancing the antibacterial and antioxidant properties of cotton fabric, while also revealing a harmony between functional performance and comfort characteristics. Full article

Biopolymers and bioactive peptides of plant origin represent sustainable resources with high potential for the development of functional ingredients with health benefits. An underutilized plant source of antihypertensive peptides is lima bean protein (Phaseolus lunatus); however, these peptides can be inactivated or degraded during their passage through the gastrointestinal tract. This study evaluated chia (Salvia hispanica) mucilage (CM) combined with sodium alginate (Al) as a hybrid encapsulation matrix for ACE-inhibitory peptides (<10 kDa) from P. lunatus. The ionic gelation technique was used, and encapsulation conditions were optimized using a 2³ factorial design that evaluated CM:Al ratios, calcium concentration, and hardening time. The optimal formulation (30:70 CM:Al; 0.05 M CaCl₂; 20 min of hardening time) achieved approximately 48% encapsulation efficiency and maintained the peptides’ ACE-inhibitory (IC₅₀ mg/mL) activity during simulated gastric digestion with controlled intestinal release. The formed capsules demonstrated good flow properties, thermal stability up to 178 °C, and preserved ACE-I activity (0.1 mg/mL IC₅₀) significantly better than alginate alone after in vitro digestion. These findings suggest that CM:Al blends could produce capsules with the ability to protect bioactive peptides with low molecular weight, warranting further investigation through in vivo bioavailability studies and structural characterization to confirm the proposed matrix-enhancing mechanisms. Full article

Waterlogged archaeological wood is highly vulnerable to degradation by wood-degrading microorganisms. Oregano essential oil (OEO) shows excellent antimicrobial activity against such microbes, but its high volatility and poor stability restrict direct application in cultural relic protection. This study aims to optimize the preparation of sodium alginate (SA)-based OEO microcapsules (OEO@SAM), characterize their structural and physicochemical properties, and evaluate their sustained-release antimicrobial performance for waterlogged archaeological wood conservation. OEO@SAM was fabricated via ionic crosslinking, with orthogonal experiments optimizing three key parameters: OEO:SA ratio, SA concentration, and CaCl₂ concentration. The microcapsules were characterized by morphological observation, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), etc. Encapsulation efficiency (EE), in vitro sustained-release kinetics, and antimicrobial activity against dominant wood-degrading microorganisms (isolated from waterlogged archaeological sites) were tested. The OEO:SA ratio was the dominant factor regulating EE: EE decreased sharply as the OEO:SA ratio increased, with the highest EE (24.05%) achieved at OEO:SA = 0.5, SA = 2%, and CaCl₂ = 3%. Meanwhile, only 0.71 g/L of OEO@SAM is required to inhibit bacterial growth and achieve the conservation of waterlogged archaeological wood. OEO@SAM exhibited stable sustained release (fitting the zero-order kinetic model) and significant antimicrobial activity against target microorganisms. It provides a new type of antibacterial and antifungal material for the in situ conservation of waterlogged archaeological wood. Full article

Antarctic krill oil (AKO) is a valuable nutraceutical; however, it is highly susceptible to oxidation. Encapsulation represents an effective strategy to enhance the storage stability of AKO. This study explored a novel approach for encapsulating AKO using sodium alginate (ALG) and gelatin (GLN) to improve its stability, and multiple parameters were systematically evaluated, including oil-loading efficiency, surface oil content, particle size, water activity, and thermal stability. Additionally, core-material retention efficiency, acid value, peroxide value, and anisidine value were measured after accelerated oxidation. The results demonstrated that the optimal encapsulation conditions consisted of an ALG:GLN ratio of 2:1, a 9% CaCl₂ coagulation bath, 750 μm nozzle size, followed by freeze-drying. Under these conditions, the microcapsules achieved an oil-loading efficiency of 62.63% and a surface oil content of 19.21%. The water activity of the microcapsules was 0.516. Thermogravimetric analysis indicated that AKO microcapsules encapsulated with ALG/GLN exhibited higher thermal stability (~300 °C) compared to those encapsulated with ALG alone (~280 °C). When AKO or its microcapsules were subjected to accelerated oxidation at 65 °C, compared to ALG-encapsulation alone, the ALG/GLN encapsulation system significantly reduced the oxidation indicators of the oil, such as acid value (24%), peroxide value (26%), and anisidine value (28%). In conclusion, incorporating GLN into ALG-based microcapsules significantly enhanced the antioxidant capacity of AKO and prolonged its shelf life. Full article

Three-dimensional (3D) cell culture systems require biocompatible carriers that provide both structural support and efficient mass transport. Conventional alginate-based encapsulation systems suffer from poor molecular diffusion, lack of cell adhesion motifs, and structural instability under physiological conditions. Here, we report the first development of hollow-shell collagen microcapsules (CMCs) fabricated via a gelatin sacrificial template approach that overcomes these critical limitations. The hollow architecture combined with collagen’s intrinsic bioactivity achieved 2.5-fold enhancement in molecular permeability compared to conventional alginate beads, while maintaining structural integrity for 14 days versus 3-day collapse of alginate controls. NIH 3T3 fibroblasts encapsulated within CMCs demonstrated superior proliferation and formed tissue-like multilayered structures with extensive extracellular matrix deposition. This platform represents a significant advance in 3D cell culture technology, providing a biologically functional microenvironment with enhanced mass transport properties for applications in tissue engineering and regenerative medicine. Full article

This study focused on the preparation of microcapsules that simulate adipose tissue cells via complex coacervation, followed by the formation of block-like fat analogue products through gelation. The results indicated that microcapsules obtained by encapsulating coconut oil with soy protein isolate (SPI) and sodium alginate (SA) through a complex coacervation process could serve as effective fat substitutes in meat products. When the mass ratio of SPI to SA was 3:1, the core-to-wall mass ratio was 1:1, and the total wall material concentration was 3% (w/v), the oil loading rate of the microcapsules reached 39.17%. The particle size of the oil-loaded microcapsules was mainly distributed between 40–180 μm, which was comparable to the size of fat cells in animal adipose tissue. Microcapsules (50%, w/w) were mixed with a 5% (w/v) curdlan dispersion and heated at 95 °C for 60 min to form fat analogues. The fat analogues demonstrated significantly reduced cooking loss, enhanced textural rigidity, and superior chew resistance, achieving performance metrics comparable to those of natural adipose tissue. This dual-phase strategy—combining interfacial engineering of lipid microcapsules with polysaccharide-mediated gelation—provides a promising approach for developing sustainable, plant-based fat alternatives in meat product reformulation. The methodology not only addresses texture and flavour challenges in fat replacement but also enables precise control over lipid content, supporting applications in healthier food systems. Full article