Search Results (628)

The aim of this study was to investigate the biochemical properties of free and immobilized mushroom tyrosinase (EC 1.14.18.1) entrapped in calcium alginate beads for phenol oxidation in a batch system. Tyrosinase activity was determined spectrophotometrically at 400 nm under optimal conditions. The effects of key operational parameters on phenol oxidation kinetics were evaluated for both enzyme systems. The Michaelis–Menten constant (K_M) of the immobilized enzyme (0.94 ± 0.2 mM) was approximately twice that of the free enzyme (0.56 ± 0.04 mM), while its maximum reaction velocity (V_Max = 101.4 ± 2.2 µmol L⁻¹ min⁻¹) decreased by nearly 30-fold (V_Max(App) = 3.63 ± 0.3 µmol L⁻¹ min⁻¹). Immobilization also shifted the optimal pH of the enzyme to pH 6.0. The optimum temperature and activation energy for phenol oxidation were determined as 55 °C and 52.48 kJ/mol for immobilized tyrosinase, whereas they were 45 °C and 39.58 kJ/mol for the free enzyme. The highest level of activity was obtained with alginate beads of 2.6 mm diameter, and the immobilized preparation exhibited enhanced operational stability, completely retaining its initial activity after five reuse cycles. Overall, these findings suggest that mushroom tyrosinase immobilized in alginate beads is a promising system for phenol removal from wastewater. Full article

Ulcerative colitis (UC) is an inflammatory bowel disease associated with oxidative stress. Pogostemon oil (PO) exhibits potent antioxidant and anti-inflammatory activities but is limited by high volatility and poor gastrointestinal stability. In this study, sporopollenin exine capsules (SECs) were engineered as natural micro-carriers for PO, achieving efficient encapsulation (η > 69%) and a high adsorption capacity (27.64 g/g). A pH-sensitive calcium alginate shell was subsequently applied to construct colon-targeted microspheres (Ca-Alg@PO-SECs). The resulting system improved the thermal and photostability of PO. In vitro dissolution assays confirmed the system’s pH-responsiveness, maintaining integrity under simulated gastric conditions while enabling localized release at intestinal pH. In a DSS-induced acute UC mouse model, Ca-Alg@PO-SECs effectively alleviated clinical symptoms, as evidenced by improved body weight, colon length, and disease activity index. At the inflammatory level, the formulation modulated key cytokines (IL-1β, IL-6, and IL-10). Overall, Ca-Alg@PO-SECs provides a biocompatible, colon-targeted delivery strategy that preserves the bioactivity of essential oils and offers a promising preclinical approach for localized UC therapy. Full article

Hydrophobic nanofiber membranes derived from the biopolymer alginate were fabricated by electrospinning followed by metal ion crosslinking, and their potential as oil-water separation membranes was primarily investigated. Sodium alginate (SA) was co-electrospun with polyethylene glycol and subsequently crosslinked using calcium chloride and group IV metal ions (zirconium or titanium). Metal ion crosslinking changed the surface wettability of the nanofiber membranes, as confirmed by water contact angle measurements. Both zirconium- and titanium-crosslinked SA nanofiber membranes exhibited effective gravity-driven oil–water separation with complete water blocking. Although hydrophobic modification reduced direct water affinity, the resulting membranes retained residual adsorption capability toward methylene blue, indicating the presence of accessible internal polar sites. The adsorption behavior varied depending on the crosslinking ion. In addition, titanium-crosslinked membranes showed an auxiliary UV-assisted dye removal contribution under irradiation, arising from photoactive Ti species. These findings demonstrate that metal ion crosslinking provides a practical route for tuning the functional properties of alginate nanofiber membranes, with oil-water separation as the primary application and dye adsorption/photocatalysis as secondary functionalities. Full article

The main goal of this work was to develop nanoparticles of lysozyme (Lys) for biological and biomedical applications. The developed biosystems were based on Lys-loaded calcium alginate 2% and chitosan 1% beads and films with different concentrations of each polymer. Encapsulation efficiency was 100%. The ratio of adsorbed Lys on the films, Lys activity, and the release profile of Lys were measured using water and buffer solution at pH similar to the environment of cancer cells, at a controlled temperature of 37 °C and a constant speed, to assess the efficacy of the encapsulation process. Lys antimicrobial activity was assessed using Micrococcus lysodeikticus. Moreover, the anti-inflammatory and antioxidant properties of the developed biosystems were also evaluated. The anti-inflammatory activity of Lys released from calcium alginate 2%-chitosan 1% beads loaded with Lys was about 99%. These findings highlight the potential of the developed beads and films for biomedical applications, particularly in antimicrobial and anti-inflammatory therapies. Full article

Dialdehyde crosslinked poly aspartate/alginate hydrogel beads were synthesized by covalently introducing poly aspartate into the alginate network via dialdehyde-mediated crosslinking, and the resulting effects on swelling and adsorption behavior were investigated. Alginate was partially oxidized to form dialdehyde alginate and crosslinked with poly aspartic acid via Schiff base formation, followed by ionic crosslinking with calcium ions. The chemical structure and morphology of the gel beads were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Incorporation of PAsp significantly altered the swelling behavior of alginate-based gel beads. In saline solution, PAsp-modified gel beads exhibited a swelling ratio of approximately 112 g/g, which was higher than that of calcium alginate gel beads. This behavior is suggested to be associated with changes in the alginate–calcium network structure induced by polymer modification. PAsp-modified gel beads exhibited moderate but distinct adsorption behavior depending on the adsorbate. Removal efficiencies of approximately 40–50% were observed for copper and cobalt ions, while a removal efficiency of around 50% was obtained for the cationic dye crystal violet. In contrast, adsorption of the anionic dye Congo red decreased with increasing PAsp content, indicating charge-dependent adsorption behavior. Overall, this study demonstrates that PAsp modification via dialdehyde-mediated crosslinking influences both the swelling and adsorption properties of alginate-based hydrogel beads. The results provide fundamental insight into how network modification can be used to tune the behavior of alginate-based hydrogels in aqueous environments. Full article

Background/Objectives: Three distinct strains of lactic acid bacteria (LAB), isolated from naturally fermented bread sourdough and representing the local autochthonous microflora, were selected to evaluate their potential probiotic properties. In addition, we evaluated whether these strains could be used in topical formulations. Methods: We evaluated probiotic properties such as the ability to co-aggregate with pathogens, antimicrobial activity, inhibition of pathogenic biofilms, and ability to adhere to human keratinocyte cells. Further, bacteria were encapsulated in calcium alginate microspheres using the emulsification/external gelation method, and their viability in topical formulations was assessed. Results: LAB significantly inhibited biofilm formation by the tested pathogens with complete inhibition observed in certain cases. The strength and specificity of these probiotic effects varied depending on the LAB strain and the target pathogen. Furthermore, among the tested strains, L. reuteri 182 exhibited the highest adhesion rates, reaching 77.94 ± 1.84%. In the context of potential topical applications, the preservative present in the formulation completely inactivated the planktonic cells of L. reuteri 182. In contrast, encapsulation within a biopolymeric system conferred protection against the preservative’s bactericidal effect. After 35 days of storage at room temperature, viable cell counts reached 5.94 ± 0.06 lg CFU/g. Conclusions: Our findings confirm that local LAB strains, specifically L. reuteri 182 and L. plantarum F1, possess essential probiotic characteristics and can be effectively incorporated into preservative-containing topical formulations via efficient encapsulation strategies. This underscores the potential of these topical probiotics for skin health and highlights the need for clear regulatory guidance to ensure their safe and effective application. Full article

Packaging can help prolong the shelf life of perishable agrifoods. In the present investigation, edible coatings were tested to reduce food waste caused by filamentous fungi and increase the shelf-life of high-value products such as strawberries, tomatoes, and blueberries. Different combinations of sodium alginate and calcium chloride, and various immersion times were tested on tomato as a model. The ability to activate edible coatings with food-grade compounds/extracts, such as sodium bicarbonate or Moringa oleifera extract (MLE), was explored. The extract was also tested in vitro against some of the main postharvest pathogens, such as Botrytis cinerea, Alternaria alternata, Rhizopus stolonifer, Colletotrichum acutatum, and Penicillium expansum. The most suitable composition for the edible coating proved to be 2% sodium alginate and 2% calcium chloride. MLE proved not to reduce fungal growth, except for A. alternata and C. acutatum. Concerning active coatings, particularly those containing MLE, there was a reduction in the incidence of rots on strawberries (−45%) and tomatoes (−59%) as compared to the uncoated control. Furthermore, a reduction in the severity of rots was recorded in all tested fruits (−73% in tomato, −88% in strawberries, −47% in blueberries) as compared to the uncoated control. The active edible coatings could play a role in reducing rots, contributing to the extension of the shelf-life of the selected products. Full article

Extensive application of deltamethrin on agricultural products results in serious contamination of the environment. Its negative impact on environmental and public health necessitates the development of environmental remediation technologies. Detailed investigations of microbial degradation of deltamethrin may be useful for the development of bioremediation strategies. In this study, the deltamethrin removal capability of a bacterial strain, Microbacterium sp., previously isolated from the gut of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) was first investigated. When 3 mL of the bacterial solution (OD₆₀₀ = 1) was inoculated into 97 mL of MS media containing 200 μg/mL deltamethrin, it could remove 45.7% deltamethrin after 64 h of incubation. This strain grew fastest in LB media with an inoculum volume of 3% in pH 7 at 175 rpm, 25 °C. To enhance its environmental tolerance, this strain was immobilized with sodium alginate. Microbacterium sp.-containing calcium alginate microspheres (CAMs) exhibited an enhanced deltamethrin removal capability compared to free bacteria, and CAMs generated by immobilization with 2% sodium alginate and 3% CaCl₂ cross-linking for 4 h possessed the maximum deltamethrin removal capability. The ultrastructure of Microbacterium sp.-containing CAMs prepared under optimal conditions was a three-dimensional mesh structure with pores and dense features, and the bacteria grew well in the immobilized carrier. After being reused five times, the deltamethrin removal rate of immobilized Microbacterium sp. still reached over 50%. When Microbacterium sp. was inoculated into deltamethrin-contaminated water or soil for 48 h, the deltamethrin removal rate of immobilized bacteria was 1.4 times higher than that of free bacteria. These results suggest that Microbacterium sp.-containing CAMs possess an excellent deltamethrin removal capability and good reusability, showing great potential for the remediation of deltamethrin-contaminated environments. Full article

This study aimed to develop functional calcium alginate hydrogels incorporating Chlorella vulgaris, carob (Ceratonia siliqua L.), and encapsulated Lactobacillus acidophilus in edible jelly gums with enhanced bioactivity and probiotic viability. Laboratory-prepared jellies containing encapsulated probiotics (encapsulated LAB-Jelly) and those with free cells (LAB-Jelly) were compared with a commercial jelly sample. The formulations were evaluated for phenolic content, antioxidant capacity and antiradical activity, texture, sensory characteristics, and probiotic survival under simulated gastrointestinal conditions. The encapsulated LAB-Jelly exhibited significantly higher total phenolic content (4.6 ± 0.1 mg GAE/g) and antioxidant activity (25.9 ± 0.1 mg Fe⁺²/g) compared to the commercial product, mainly due to the presence of carob and Chlorella. Texture analysis showed lower hardness (21.8 N) but comparable elasticity (89.3%) and cohesiveness (72.8%) comparative to commercial jelly gum, while sensory evaluation confirmed their favorable acceptability and non-perceptible bead presence. Microencapsulation achieved 75% efficiency and improved probiotic survival during gastrointestinal simulation after 18 h (14% reduction in Logcfu/mL compared to 30% of the free probiotics). Overall, the combination of alginate encapsulation, Chlorella, and carob produced edible jelly gums with improved antioxidant and textural properties, offering a promising delivery system for functional foods enriched with probiotics and plant-based bioactives. Full article

Alginate nanocapsules loaded with Moringa oleifera extract, a plant traditionally used for its hypoglycemic properties, were developed as a therapeutic alternative for type II diabetes mellitus. The nanocapsules were obtained by manually spraying a WO emulsion with an airbrush and were stabilized in 2% calcium chloride. Characterization by atomic force microscopy revealed spherical particles with an average diameter of 10.087 nm, an area of 298.441 nm², and a density of 0.207556/nm², confirming efficient encapsulation and uniform morphology. This low-cost method is promising for the creation of controlled release systems in resource-limited settings. Full article

Antibiotics are increasingly detected in aquatic environments, raising environmental and public health concerns due to their persistence and contribution to antimicrobial resistance. This study examines copper sulfide (CuS) nanostructures as potential materials for sustainable water remediation. CuS nanoparticles were synthesized in aqueous media using thioglycolic acid (TGA) as a stabilizing ligand and characterized by UV–Vis, FTIR, XRD, TEM, SEM, and EDS. An optimized Cu:TGA molar ratio of 1:6 yielded stable nanoparticles with a distinct excitonic absorption at 312 nm, strong ligand coordination, and a covellite-type hexagonal crystalline phase. These nanoparticles were subsequently immobilized within calcium–alginate hydrogel beads of two controlled size regimes, producing structurally uniform and recoverable composites. SEM imaging revealed qualitative increases in surface texturing following CuS incorporation, while bead diameter analyses indicated minimal changes in morphology. Overall, the results confirm the successful synthesis, stabilization, and immobilization of CuS nanoparticles within alginate beads and establish a robust materials platform with potential for future adsorption and photocatalytic applications targeting antibiotic contaminants in water. Full article

Background/Objectives: The ABCG2 transporter actively effluxes anticancer drugs, reducing their efficacy and promoting multidrug resistance (MDR). Developing oral formulations of poorly soluble ABCG2 inhibitors remains challenging due to their low solubility and intestinal permeability. This study aimed to formulate and evaluate an ABCG2 inhibitor using micro- and nanoscale drug delivery systems. Methods: To address the poor solubility and bioavailability of the corresponding active ingredient, a self-nanoemulsifying drug delivery system (SNEDDS) was developed. The SNEDDS was encapsulated into microcapsules using sodium alginate crosslinked with calcium chloride. Five microcapsule formulations were developed, varying in the inclusion of polyvinylpyrrolidone (PVP), Transcutol^® HP and SNEDDS. The effects of the excipients on encapsulation efficiency, swelling capacity, enzymatic stability, dissolution, cytocompatibility, and permeability were systematically evaluated. Results: The SNEDDS exhibited monodisperse particle sizes and efficient drug entrapment. Results revealed that formulations incorporating PVP and SNEDDS improved encapsulation efficiency and bioavailability. SNEDDS-containing formulations demonstrated superior enzymatic stability in simulated gastric and intestinal fluids and provided the highest cumulative drug release in vitro. Cytotoxicity studies conducted on Caco-2 and MCF-7 cells demonstrated that our formulations were well tolerated, indicating favorable biocompatibility. Conclusions: Our findings demonstrate that SNEDDS-loaded alginate microcapsules offer an efficient platform for oral delivery of dimeric ABCG2 inhibitors, combining enhanced solubility, stability, and controlled release. The optimized formulation can be regarded as a promising strategy to enhance the oral bioavailability of efflux pump inhibitors and other poorly soluble drugs. Full article

This study aimed to develop a microencapsulation formulation for efficient encapsulation of β-glucosidase to improve its stability in a rumen-like environment and sustain activity post-rumen in the ruminant gut. Various alginate-based formulations were evaluated to achieve high encapsulation efficiency (EE) and stability. These included control alginate beads (AB), microcapsules with chitosan (MCS), alginate–sucrose beads (AOS), alginate–sucrose–maltodextrin beads (AOMS), and alginate pectin beads (APB). The microcapsules were made using Buchi encapsulator B-390 with calcium chloride as the gelling solution. Alginate proved to be a suitable polymer for β-glucosidase encapsulation and <1 mm diameter microbeads were obtained across all formulations. Alginate alone (AB: 1% alginate, 0.2 U/mL β-glucosidase) showed low EE (3% ± 1.0) due to leakage and syneresis. Modifying the gelling solution with 0.1% chitosan (MCS) increased EE to 49 ± 2.64% by reducing alginate porosity. Further improvements were achieved by adding stabilizers to the alginate solution (AB), in addition to using the modified gelling solution (MCS): Adding sucrose (AOS) at 4% increased EE to 95.5 ± 2.08%, while adding sucrose (4%) and maltodextrin (2%) (AOMS) achieved 100 ± 2.16%. On the other hand, adding pectin (4%) (APB) to the alginate solution resulted in a lower EE of 40.5% ± 2.55, likely due to interference with alginate crosslinking. In vitro rumen fermentation showed a dry matter degradation of 42–54%, underscoring the need for more robust microcapsules. Encapsulation strategies, such as incorporation of additional protective layers, are essential to enhance bead stability, minimize degradation, and improve enzyme retention, to ensure efficient delivery and sustained enzymatic activity in the hindgut. Full article

Sodium alginate (SA) is widely used as an edible coating for fruit preservation, but its weak water barrier and antibacterial properties limit broader application. In this study, quaternary ammonium lignin–cinnamaldehyde (QKC) composite particles were incorporated into SA as multifunctional fillers to construct antibacterial coatings. Electrostatic and hydrogen-bonding interactions between cationic QKC and anionic SA yielded a uniform, stable network with improved hydrophobicity and UV-shielding capacity. At 5 wt% QKC loading (SA5), the tensile strength increased from 11.53 to 24.42 MPa (111.8% higher than SA0), while water vapor permeability decreased by 35.4%. SA coatings also exhibited strong antioxidant activity, and the ABTS radical scavenging rate increased to 70.22% at 7 wt% QKC, with SA5 offering a favorable balance between antioxidant, barrier, and mechanical properties. SA5 showed pronounced antibacterial efficacy, giving inhibition rates of 96% against Staphylococcus aureus and 65% against Escherichia coli. Coating trials on persimmons and tangerines demonstrated that SA5 reduced weight loss, delayed firmness decline, and mitigated decay during storage. In addition, calcium-crosslinked SA/QKC hydrogel beads markedly delayed visible mold growth on blueberries. These results indicate that QKC-reinforced SA coatings provide a promising strategy for enhancing the postharvest quality and shelf life of fresh fruit. Full article

Alginate-based microcapsules have gained considerable attention as drug delivery systems due to their biocompatibility, biodegradability, and ability to encapsulate therapeutic agents. In this study, microcapsules were synthesized by crosslinking with calcium ions, with albumin serving as a carrier for doxorubicin. The goal was to develop a stable system capable of controlled drug release under physiological conditions, with potential applications in cancer therapy. Sodium alginate was used as a base polymer, which formed a stable matrix after crosslinking with calcium ions. The resulting microcapsules showed a uniform size distribution in the microscale range. Analyses confirmed their stability in simulated physiological environments with minimal degradation. Observations revealed a homogeneous structure of the microcapsules, while incubation studies confirmed controlled drug release triggered by pH changes. The results indicate that alginate–albumin microcapsules can serve as an effective platform for drug delivery, especially in cancer therapy and other biomedical applications. Full article