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Materials combining stretchability and sensitivity to external stimuli are key for wearable electronics applications to enable the emergence of disruptive technologies in biosensing, health monitoring, photodetection and human motion recognition. Conductive organohydrogels have gained significant attention due to their high sensitivity and cost‐effective preparation. Biopolymers like gelatin and alginate offer unique opportunities for developing responsive wearable devices, owing to their biocompatibility and sensitivity toward environmental factors. Here sustainable bio‐inspired method is presented to produce alginategelatin organohydrogels combining transparency in the visible range, ionic conductivity, high stretchability, and multiresponsiveness. The controlled alginate's crosslinking with various metal cations like Mn2+, Cu2+, Fe3+, and Zr4+ enables modulating ionic conductivity as well as finely tuning the material's thermal and mechanical properties. These organohydrogels show responsiveness to temperature (from 10 to 50 degrees, with a sensitivity of 0.19 K−1), relative humidity (from 20 to 80%, with a sensitivity of 0.022 RH(%)−1), and strain (gauge factor >1.6), enabling real‐time monitoring of environmental and physiological parameters. Remarkably, they also exhibit photoresponsivity of 9.2 µA W−1 under visible light, a feature rarely reported in literature. The ease of tuning responsiveness to the chosen stimuli and the high sensitivities open perspectives for applying these materials as wearable stretchable sensors. [ABSTRACT FROM AUTHOR]

Volumetric additive manufacturing (VAM) has emerged as a potent method for fabricating complex structures out of soft materials such as hydrogels. In this study, a low‐cost photopolymer platform is developed based on low molecular weight poly (ethylene glycol) diacrylate (PEGDA) and alginate (Alg) blends which reduces material costs ≈1000x. By adding non‐crosslinked 0.5 wt.% of Alg to these 5, 10, or 15 wt.% PEGDA precursor solutions, the viscosity is raised from <1 mPa*s to 50 mPa*s, which enables VAM of low molecular weight PEGDA. The fabricated hydrogels have customizable mechanical properties, ranging from 14 ± 4 kPa to 90 ± 24 kPa, and 289 ±121 kPa and correspond to equilibrium water contents of 96.8 ± 0.3%, 91.2% ± 0.8% and 84.1% ± 0.9%. The printed structures have minimum feature sizes ranging between 56 ± 9 µm for 5 wt.% PEGDA + 0.5 wt.% Alg, 47 ± 12 µm for 10 wt.% PEGDA + 0.5 wt.% Alg, and 39 ± 7 µm for 15 wt.% PEGDA + 0.5 wt.% Alg. Additionally, these materials are printable into designs with internal voids, unsupported struts, and interlocked features. This work establishes a low cost, mechanically tunable hydrogel platform for VAM which can improve accessibility and adoption. [ABSTRACT FROM AUTHOR]

Targeted at organic dye pollutants, a stable HOF was combined with an alginate (SA) hydrogel to enhance the affinity for cationic dyes. The as-obtained HOF@SA membrane (weight ratio: 1/1) shows a high adsorption capacity (729.21 mg g−1), adsorption selectivity and good recycling performance towards methylene blue. [ABSTRACT FROM AUTHOR]

ABSTRACT Chicken thigh is a popular and widely consumed meat product. However, its high moisture content and susceptibility to microbial spoilage limit its shelf life. To address this issue, we investigated the efficacy of an edible coating based on alginate nanoparticles (AlgNPs) containing menthol, Zataria multiflora essential oil (EO), or their combination for extending the shelf life of chicken thigh. The nanoparticles were prepared through ionic gelation methods; their particle size was obtained as 87–205 nm with PDI values of < 0.3 and SPAN values of < 1. The AlgNPs containing both menthol and the EO showed the most potent antimicrobial activity (the lowest counts of pseudomonas, aerobic mesophilic, and yeast‐mold), during cold storage. This coating treatment showed also the highest antioxidant activities, with the lowest thiobarbituric acid reactive substances (TBARS), pH and total volatile basic nitrogen (TVBN) values. Moreover, this coating significantly (p < 0.05) showed the highest sensory quality of chicken thighs, as evidenced by the higher sensory scores for texture, odor, color, and overall acceptability. Therefore, the edible coating based on AlgNPs containing menthol and Z. multiflora EO is an effective and promising approach for extending the shelf life of chicken thighs. [ABSTRACT FROM AUTHOR]

Probiotics (PRO) have been recognized for their significant role in promoting human health, particularly in relation to colon-related diseases. The effective delivery of PRO to the colon is a fascinating area of research. Among various delivery materials, carbohydrates have shown great potential as colon-targeted delivery (CTD) carriers for PRO. This review explores the connection between probiotics and colonic diseases, delving into their underlying mechanisms of action. Furthermore, it discusses current strategies for the targeted delivery of active substances to the colon. Unlike other reviews, this work specifically focuses on the utilization of carbohydrates, such as alginate, chitosan, pectin, and other carbohydrates, for probiotic colon-targeted delivery applications. Carbohydrates can undergo hydrolysis at the colonic site, allowing their oligosaccharides to function as prebiotics or as direct functional polysaccharides with beneficial effects. Furthermore, the development of multilayer self-assembled coatings using different carbohydrates enables the creation of enhanced delivery systems. Additionally, chemical modifications of carbohydrates, such as for adhesion and sensitivity, can be implemented to achieve more customized delivery of PRO. [ABSTRACT FROM AUTHOR]

Alginate biopolymer is widely employed in many industrial fields thanks to its pleasing features of biodegradability, biocompatibility, low toxicity, and relatively low cost. The gelling process of alginate with divalent cations is fairly simple and thus it is used as a versatile biomaterial to tailor the desired mechanical and moisture properties. This study focused on developing new gel formulations to enhance the properties of calcium‐alginate hydrogel (CA). The newly synthesized hydrogels, referred to as CA‐CHEM gels, were chemically cross‐linked with different ratios of pentaerythritol tris[3‐(1‐aziridinyl)propionate] (PTAP) through the reaction between the carboxylic groups of alginate and aziridines of PTAP. The reaction was successfully monitored by NMR. The new CA‐CHEM gels were chemically characterized using FTIR‐ATR, while SEM analysis confirmed the changes in the porosity and homogeneity of the network. Additionally, thermogravimetric analyses and mechanical properties showed improvement in degradation stability and in structural strength, compared to plain CA, with an increasing PTAP content up to 1 % w/w. Finally, the new CA‐CHEM gels effectively controlled water absorption and release. In particular, CA‐CHEM‐1 performed as the most controlled system, making it promising for delivering aqueous cleaning solutions on water‐sensitive surfaces such as a wooden historical musical instrument. [ABSTRACT FROM AUTHOR]

Is it necessary to modify the structure of chitosan and alginate before their use in adsorption? If yes, what type of modification can be used, and what agent should be chosen for the modification? Is there a difference between grafting and crosslinking agents and what are the benefits of each after adsorption? This review article tries to answer these questions by comparing the efficiency of biosorption of certain metals on alginate and chitosan, both before and after modification. Understanding the limitations, benefits, and drawbacks of each type of modification is essential in the field of water and wastewater treatment. Hence, this review discusses the advantages and disadvantages of using each grafting agent and the benefits of modifying the alginate and chitosan adsorbents. It tries to develop insights into the linkage between selected modification agents and types of pollutants and their bonding preferences with respect to –O, –N, and –S atoms. Thus, it highlights the contributions of each functional group added to alginate and chitosan structures through grafting, cross-linking, or both. Also, it elaborates on the corresponding benefits of each functional group (or modification) in the biosorption process. The type of contribution of each type of modification to the sorption efficiency, the way pH changes affect, reduction in adsorbent dose, the mechanisms involved in the process, the nature of adsorption, and other added properties in comparison to their natural forms, are discussed in this review, and some perspectives are suggested for future studies. Based on the concepts and ideas discussed in the current review, one can make more informed and insightful choices when selecting and modifying the studied adsorbent. [ABSTRACT FROM AUTHOR]

Background: Modern PET reconstruction algorithms incorporate point‐spread‐function (PSF) correction to mitigate partial volume effect. However, PSF correction can introduce edge artifacts that lead to quantification errors. Consequently, current international guidelines advise against using PSF correction in brain PET reconstruction. Purpose: We aimed to investigate PSF‐induced quantification errors in recent digital PET systems and identify conditions that mitigate them. This study utilized brain PET imaging with alginate‐based realistic phantoms, simulating lesion‐to‐background activity ratios of 10:1 and 2:1, with eleven reconstruction parameter sets. Methods: Phantoms were prepared using a commercial anthropomorphic head phantom and two homemade inserts. Each insert contained a homogeneous 18F‐FDG alginate background with hot spheres of varying diameter (3, 4, 6, 8, 10, 12, and 15 mm). PET imaging was conducted on a digital PET‐CT system Biograph Vision 600 (Siemens), with a 10 min scan duration. Imaging was performed with and without PSF correction, with 2, 4, 6, 12, 18, or 24 iterations in reconstruction, and with or without additional Gaussian postfiltering. We assessed the recovery coefficient (RC), contrast recovery coefficient (CRC), variability, and CRC‐to‐variability ratios for each sphere size and reconstruction parameter set. Results: PSF‐corrected images of the 10:1 spheres exhibited a nonmonotonic CRC‐to‐sphere diameter relationship due to edge artifacts overshoot in the 10 mm‐diameter sphere. In contrast, PSF images of the 2:1 spheres showed a monotonically increasing relationship. Non‐PSF images of both phantoms showed an expected monotonically increasing CRC‐to‐sphere diameter relationship but with lower CRC values compared to PSF images. The nonmonotonic relationship observed with 10:1 spheres was mitigated by applying a 3‐mm FWHM Gaussian postfiltering. For both phantoms, reconstructions with 6 iterations, PSF correction, and additional 3‐mm FWHM Gaussian postfiltering demonstrated the highest CRC‐to‐variability ratios. Conclusions: Our findings indicate that Gaussian postfiltering suppresses PSF artifacts. This parameter set corrected the nonmonotonic CRC‐to‐sphere diameter relationship and improved the CRC‐to‐variability ratio compared to non‐PSF reconstructions. Therefore, to enhance lesion detectability without compromising quantification accuracy, PSF correction coupled with Gaussian postfiltering should be used in brain PET. [ABSTRACT FROM AUTHOR]

Alginate, a polysaccharide found in brown seaweeds, has regularly gained attention for its potential use as a source of bioactive compounds. However, it is structurally complex with a high molecular weight, limiting its application. Alginate oligosaccharides (AOS) are small, soluble fragments, making them more bioavailable. Alginate hydrolysis by enzymes is the preferred method for AOS production. Commercially available alginate lyases are limited, expensive, and sometimes exhibit unsatisfactory activity, making the search for novel alginate lyases with improved activity indispensable. The aims of this study were to codon-optimise, synthesise, express, purify, and characterise a recombinant alginate lyase, AL2, from Flammeovirga sp. strain MY04 and to compare it to a commercial alginate lyase. Expression was successfully performed using Escherichia coli ArcticExpress (DE3) RP cells, and the protein was purified through affinity chromatography. The recombinant enzyme was characterised by pH optimum studies, and temperature optimum and stability experiments. The optimal reaction conditions for AL2 were pH 9.0 and 37 °C, while for the commercial enzyme, the optimal conditions were pH 8.0 and 37 °C. At optimal reaction conditions, the specific activity of AL2 was 151.6 ± 12.8 µmol h−1 mg−1 protein and 96.9 ± 13.1 µmol h−1 mg−1 protein for the commercial alginate lyase. Moreover, AL2 displayed impressive activity in breaking down alginate into AOS. Hence, AL2 shows potential for use as an industrial enzyme for the hydrolysis of alginate into alginate oligosaccharides. Additional studies should be carried out to further characterise this enzyme, improve its purity, and optimise its activity. [ABSTRACT FROM AUTHOR]

Alginate fibers have excellent flame-retardant properties and make up for other material defects by blending. To investigate the influence of the blending ratio of alginate fibers on the flame-retardant properties of waterproof and breathable layers for firefighting suits, this paper utilizes the needle-punching and hot-pressing nonwoven reinforcement processes to prepare waterproof and breathable layers based on alginate/aramid base cloths and conducts a series of performance tests on them. The results show that the char residue content of alginate blended base cloth is significantly improved relative to pure aramid, and the addition of alginate fibers to the base cloth of the waterproof and breathable layer improves its flame retardancy and thermal stability. The overall performance of the alginate/aramid blended base fabric waterproof and breathable layer was better than that of the aramid-based waterproof and breathable layer. Moreover, in the flame-retardant multilayer fabric system for firefighting apparel, the multilayer fabric system containing the alginate/aramid-based waterproof and breathable layer showed higher thermal protection performance. Therefore, the alginate/aramid-based waterproof and breathable layer can enhance the overall flame-retardant performance of firefighting clothing to a certain extent. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a common brain disease associated with cognitive impairment and dementia. donepezil, an acetylcholinesterase (AChE) inhibitor drug as a commercial AD drug represents a non-cost-effective treatment with the toxic effects reported. As the prevalence of AD increases, the development of effective therapeutic treatments is urgently required. Laminaria digitata is a brown seaweed claimed to be able to prevent and treat neurodegenerative diseases. Therefore, this study measured and compared the binding affinity and toxicity of seven common phytoconstituents in Laminaria digitata against acetylcholinesterase (AChE) with those of donepezil using a molecular docking approach. The binding free energy values of donepezil, dieckol, eckol, fucodiphlorethol G, 7-Phloroecol, laminaran, alginic acid, and fucoidan with acetylcholinesterase (AChE) were −12.3, −13.5, −10.5, −8,7, −9.7, −8.0, −10.3, and −7.4 kcal/mol. All ligands constantly interacted with the AChE amino acid residues, namely Tyr124. Dieckol, with the strongest and most stable interaction, is classified as class IV toxicity, with an LD50 value of 866 mg/kg. It has aryl hydrocarbon receptor (AhR) and mitochondrial membrane potential (MMP) toxicity at certain doses. Theoretically, based on Lipinski's rule, dieckol is likely to have poor absorption and permeation properties; therefore, several considerations during the drug discovery process are needed. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa is a multidrug-resistant bacterium capable of forming biofilms. This study aimed to assess resistance of clinical isolates from Libyan hospitals to antipseudomonal antibiotics, the prevalence of selected extended-spectrum β-lactamases and carbapenemase genes among these isolates, and the microorganisms' capacity for alginate and biofilm production. Forty-five isolates were collected from four hospitals in Benghazi and Derna, Libya. Antimicrobial susceptibility was determined using agar disc diffusion. The presence of resistance genes (blaCTXM, blaTEM, blaSHV-1, blaGES-1, blaKPC, and blaNDM) was screened using PCR. Biofilm formation was quantified via the crystal violet assay, while alginate production was measured spectrophotometrically. Resistance to antipseudomonal antibiotics ranged from 48.9% to 75.6%. The most prevalent resistance gene was blaNDM (26.7%), followed by blaGES-1 (17.8%). Moreover, all isolates demonstrated varying degrees of biofilm-forming ability and alginate production. No statistically significant correlation was found between biofilm formation and alginate production. The dissemination of resistant genes in P. aeruginosa, particularly carbapenemases, is of great concern. This issue is compounded by the bacteria's biofilm-forming capability. Urgent intervention and continuous surveillance are imperative to prevent further deterioration and the catastrophic spread of resistance among these formidable bacteria. [ABSTRACT FROM AUTHOR]

This study focuses on encapsulating and characterizing essential oils such as thyme and calendula oils, which are known for their therapeutic properties but are limited in pharmaceutical formulations due to their low water solubility and instability, with alginate microspheres. Alginate presents an excellent option for microencapsulation due to its biocompatibility and biological degradability. The ionic gelation (IG) technique, based on the ionic binding between alginate and divalent cations, allows the formation of hydrogel materials with high water content, mechanical strength, and biocompatibility. The microspheres were characterized using FT-IR, SEM, and swelling analyses. After determining the encapsulation efficiency and drug loading capacity, the microspheres were subjected to dissolution studies under simulated digestion conditions. It was observed that the swelling percentage of the microspheres in simulated gastric fluid (SGF) ranged from ∼15% to 100%, while in simulated intestinal fluid (SIF) it ranged from ∼150% to 325%. Thyme oil, with low viscosity, exhibited higher encapsulation efficiency than marigold oil. The highest encapsulation efficiency was observed in A-TO-2 microspheres, while the highest drug loading capacity was observed in A-TO-5 microspheres. During the examination of the dissolution profiles of the microspheres, dissolution rates ranging from 10.98% to 23.56% in SGF and from 52.44% to 63.20% in SIF were observed. [ABSTRACT FROM AUTHOR]

Electrochemical synthesis and characterization of Zn‐alginate hydrogel films and their antioxidant and antimicrobial activity are evaluated. Swelling properties, zinc concentration and spectroscopic and morphological features were characterized and related to their antimicrobial and antioxidant activity. These results indicate a dependence of swelling on the degree of cross‐linking, which, in turn, can be adjusted by manipulating the synthesis time, initial alginate concentration and/or zinc leaching. Hydrogel films with zinc showed remarkable antibacterial properties, especially against gram‐positive bacteria. The absence of Zn resulted in less inhibition of gram‐positive strains, although it had a positive effect on the inhibition of gram‐negative strains, which was attributed to the degradation of alginate chains, affecting cell metabolism. Nitrogen‐doped samples synthesized in rivanol‐containing solution exhibited globular morphology and higher antioxidant activity. The electrochemical synthesis enables the facile preparation of highly active alginate hydrogels for biomedical applications. [ABSTRACT FROM AUTHOR]

Zirconium‐based metal‐organic frameworks (Zr‐MOFs) represent an important class of MOFs with high stability and outstanding properties, the green preparation and shaping of which are still challengeable works to hinder their real‐world applications. In this presentation, UiO‐66‐NH2 MOFs were in‐situ grown accompanied by alginate (Alg) hydrogelation under aqueous conditions, achieving UiO‐66‐NH2/Alg composite hydrogels. Relevant characterizations demonstrate the in‐situ generated UiO‐66‐NH2 MOFs were evenly distributed in hydrogel networks by attaching on Alg fiber surfaces. The network structure became denser, but both specific surface area and pore volume were augmented due to the presence of MOFs, which in turn increased active sites to interact with adsorbates. Thus, the adsorption capacity to methylene blue (MB) of composite hydrogels became higher with more dosage of MOF ligand, and the pH sensitivity of Alg adsorption to MB in the pH range of 4 to 10 was eliminated. Furthermore, the study of adsorption kinetics and isotherm reveals MB adsorption on the obtained hydrogels belong to rate controlling chemisorption mechanism. In summary, this manuscript presents a facile approach to realizing the green synthesis and shaping of Zr‐MOFs by one‐step compositing of UiO‐66‐NH2 with Alg‐based hydrogels in aqueous system, achieving MOFs‐based composite hydrogels with enhanced MB adsorption. [ABSTRACT FROM AUTHOR]

AbstractAlginate lyase, which catalyzes the cleavage of alginate, has potential biocatalytic applications in agriculture, food, fodder, nutraceutical, pharmaceuticals, medical diagnostic and bioenergy industries. In this study, a novel alginate lyase-producing Streptomyces sp. LB55 (GenBank Accession No. MT176164) was isolated from Sargassum seaweed waste, and its extracted alginate lyase was immobilized onto glutaraldehyde cross-linked silicon dioxide nanoparticles. Fourier-transform infrared (FTIR) spectroscopic analysis suggests the binding of extracted alginate lyase with silicon dioxide nanoparticles via covalent bonds. FTIR analysis also revealed the retention of the secondary structure of immobilized alginate lyase by exhibiting amide I and amide II bands. The glutaraldehyde cross-linked silicon dioxide nanoparticles retained 71.9 ± 2.63% of alginate lyase activity. The optimal pH and temperature for maximal alginate lyase activity were recorded at pH 7.5 and temperatures of 40 and 45 °C, for free and immobilized forms, respectively. In comparison to free alginate lyase, the immobilized enzyme was thermodynamically efficient by displaying higher values of activation energy (52.3 kJ/mol), enthalpy (49.8 kJ/mol) and entropy (–69.7 J/mol/K) of catalysis. The immobilized alginate lyase had a strong affinity for alginate by exhibiting low Km (1.75 ± 0.12 mg/mL) and high Vmax (30.4 ± 2.66 U/mg-protein) values. The immobilized alginate lyase activity was unaffected at 2% NaCl concentration and could be successively reused six times without considerable loss of activity. The overall results demonstrate for the first time the potential of silicon dioxide nanoparticles as an effective matrix to immobilize alginate lyase for sustainable and cost-effective depolymerization of alginate. [ABSTRACT FROM AUTHOR]

AbstractAiming at the problem of prolonged formaldehyde release from artificial boards, a green slow-release formaldehyde scavenger was proposed in this study. Tea polyphenol microcapsules (TPM) were prepared by ionic gel-solvent evaporation method using sodium alginate/ethyl cellulose as the wall material and tea polyphenol as the core material. Fourier transform infrared spectroscopy (FTIR) analysis showed that the TPM exhibited the same characteristic absorption peaks as those of tea polyphenol, ethyl cellulose and sodium alginate. This indicates that the TPM was successfully prepared and the thermal stability of TPM meets the requirements of the hot pressing process of man-made boards. The optimal process of TPM was as follows: the mass ratio of tea polyphenol to ethyl cellulose was 2.58, the dosage of emulsifier was 1.01 g, and the mass fraction of sodium alginate was 17.23%, the encapsulation rate of TPM was 78.31%, and the average particle size was 18.69 ± 4.66 μm. After 180 min. After 180 min, the aldehyde reduction efficiency was 61.08%. In conclusion, TPM meets the requirements of the production process of wood-based panels and the need for continuous control of formaldehyde emission from wood-based panels. [ABSTRACT FROM AUTHOR]

AbstractAspergillus aculeatus pectinase was immobilized on magnetic nanoparticles coated with calcium alginate for pectin hydrolysis in guava juice by a stirred electromagnetic reactor (SER). The average crystallite size estimated by the Scherrer formula was 33.7 nm. The reaction rate in SER (701.7 U/mL) was almost twice that of the static process (362.5 U/mL). Both processes displayed a sigmoidal trend with positive cooperativity (n) of 5 and 4, respectively. Both free and immobilized pectinase showed great performance in the pH range of 4.0-7.0. After immobilization, pectinase acted optimally at 50 °C. Pectin hydrolysis was performed for over 10 successive cycles in SER losing only 30% of its initial activity. Thermodynamic activation parameters of the reaction revealed higher spontaneity and efficiency when hydrolysis was performed in SER. Pectin hydrolysis in guava juice displayed 41% turbidity and 85.5% viscosity reduction. The electromagnetic reactor displayed great potential for performing hydrolysis of pectin in guava juice. The biocatalyst showed good features for further applications in food industries. [ABSTRACT FROM AUTHOR]

To explore the effects of CaCl2 concentration on the gel properties and sensory quality of kelp alginate edible granules, the effects of CaCl2 concentration on the product of gel system of calcium alginate was characterized by texture properties, sensory scores, water holding capacity, cooking loss, freeze-thaw stability, and microstructure of the product, and the optimum CaCl2 concentration of the product was determined. Results showed that with the increase of Ca2+concentration (10 - 50 g/ L), the values of water holding capacity and freeze-thaw stability of the product were significantly decreased, and the cooking loss was significantly increased. At a high level of Ca2+, a dense gel layer was formed on the surface of the product, which could prevent the construction of a uniform gel system and decrease the water stability of the gel system. As the concentration of Ca2+was 20 g/ L, the texture properties and sensory quality of the product were optimized. Meanwhile, the dense and uniform gel network structure was established, and the gel system was stable. The above results indicated that kelp alginate edible granules prepared by 20 g/ L CaCl2 had good overall properties, and the texture properties and sensory quality were optimal. The research results could provide a reference for the development of calcium alginate gel products of kelp. [ABSTRACT FROM AUTHOR]

This study is aimed at developing alginate hydrogel filaments enriched with TEMPO (2,2,6,6‐tetramethylpiperidine‐1‐oxyl radical)–oxidized cellulose nanofibers (TOCNs) through 3D‐printing techniques for application in bone tissue engineering. The filaments were designed to act as advanced biomaterials that support bone regeneration by combining alginate dissolved in phosphate ions with TOCNs, followed by extrusion into a calcium chloride solution. This process facilitated the cross‐linking of alginate and in situ mineralization of calcium phosphate. The produced hydrogel filaments were characterized using a variety of techniques, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Additionally, in situ biomineralization tests confirmed the successful formation of apatite. Mechanical testing revealed a significant increase in tensile strength, ranging from 40 to 80 MPa, which underscores the improved structural integrity of the hydrogels. Rheological assessments demonstrated that the addition of TOCNs enhanced the viscoelastic properties of the filaments, making them more suitable for 3D‐printing applications. Cytotoxicity tests further confirmed the biocompatibility of the scaffolds, showing enhanced cell proliferation. These results suggest that incorporating TOCNs into alginate hydrogels offers a promising approach to developing functional biomaterials in tissue engineering, particularly for bone regeneration applications. [ABSTRACT FROM AUTHOR]

In today's world, water is a highly valued resource, and enhancing the quality of this natural endowment is a significant concern and a worldwide endeavor. This study sought to purify real wastewater and water tainted with methylene blue (MB) by immobilizing ZnO nanoparticles onto an alginate matrix using a straightforward approach and a three-dimensional structure. After analyzing the impact of H 2 O 2 , it was determined that 93.84% of MB was successfully removed (time = 120 min, dye concentration = 15 mg/L, catalyst amount = 2.5 g). The effects of inorganic ions and water types were investigated to simulate real wastewater conditions, and the catalyst performed satisfactorily. Alginate played a significant role in selectively removing dye, and the catalyst effectively removed 80.36% of MB and, in contrast, 20% of methyl orange (MO). The practical application of the catalyst was evaluated in textile wastewater treatment, and the catalyst showed satisfactory performance. An average 2.49% reduction in dye removal was observed after five stages of using the catalyst, demonstrating the beads' excellent stability. The composites were subjected to free radical trapping experiments to ascertain the active species. According to the results, h + and · OH acted as the main reaction species in the degradation of MB. At the end, the synergistic mechanism of adsorption and degradation in MB removal was presented. [ABSTRACT FROM AUTHOR]

In this paper, the adsorption of gatifloxacin (GAT) by three types of polystyrene nano-plastics (PSNPs), including 400 nm polystyrene (PS), amino-modified PS (PS-NH2), and carboxyl-modified PS (PS-COOH) was studied and the adsorption mechanism were assessed. Experimental findings revealed that the equilibrium adsorption capacity of PSNPs to GAT followed the order PS-NH2 > PS-COOH > PS. The adsorption was regulated by both physical and chemical mechanisms, with intra-particle and external diffusion jointly controlling the adsorption rate. The adsorption process was heterogeneous, spontaneous, and entropy-driven. Sodium chloride (NaCl), alginic acid, copper ions (Cu2+), and zinc ions (Zn2+) inhibited adsorption, with Cu2+ and Zn2+ having the strongest effect on PS-NH2. Theoretical computations indicated that π-π and electrostatic interactions dominated PS adsorption of GAT, while PS-COOH and PS-NH2 adsorbed GAT through electrostatic interactions, hydrogen bonds, and van der Waals (vdW) forces. The surface electrostatic potential of PS-COOH and PS-NH2 was considerably higher than that of PS, with the maximum vdW penetration distance of GAT-PS-NH2 being 1.20 Å. This study's findings provide a theoretical foundation for the migration and synergistic removal of antibiotics, micro-plastics (MPs), and nano-plastics (NPs). [ABSTRACT FROM AUTHOR]

Due to its widespread use and incomplete breakdown in the human body, amoxicillin has been detected in receiving water bodies. This raises significant concerns, like the promotion of antibiotic resistance, toxicity towards aquatic life, disruption of the natural balance of microbial communities within these water bodies, and the struggle of effectively removal by the traditional wastewater treatment plants. Consequently, exploring new processes to complement the existing methods is crucial. Adsorption, a promising highly efficient, selective, and versatile technique, can effectively remove contaminants, making it useful in various industries such as water treatment, pharmaceuticals, and environmental remediation. Several adsorbents are documented in the literature for drug adsorption; however, their fabrication often involves more complex steps and substances compared to chitosan and alginate, which are natural polymers that are biocompatible, non-toxic, and biodegradable. Their tunable properties and ease of modification enhance their efficacy in environmental remediation. Therefore, the novelty of this article is to understand the interaction of amoxicillin with chitosan and alginate adsorbents easily synthetized using the dripping technique. This approach allows us to explore basic principles that can be applied to more complex systems in future studies. The optimal pH for both beads was found to be 4, with adsorption capacities of 74.2 ± 0.3 mg g−1 for alginate and 80.4 ± 0.2 mg g−1 for chitosan, using 1 g of adsorbent. Kinetics studies indicated that external diffusion governs adsorption for alginate, while internal diffusion governs adsorption for chitosan. This approach underscores the potential of chitosan and alginate beads as effective adsorbents for mitigating antibiotic contamination in water systems, offering a sustainable complement to traditional treatment methods. [ABSTRACT FROM AUTHOR]

A hybrid alginate hydrogel–chitosan nanoparticle system suitable for biomedical applications was prepared. Chitosan (CS) was used as a matrix for the encapsulation of lavender (Lavandula angustifolia) essential oil (LEO) and Mentha (Mentha arvensis) essential oil (MEO). An aqueous solution of an acidic Natural Deep Eutectic Solvent (NADES), namely choline chloride/ascorbic acid in a 2:1 molar ratio, was used to achieve the acidic environment for the dissolution of chitosan and also played the role of the ionic gelator for the preparation of the chitosan nanoparticles (CS-NPs). The hydrodynamic diameter of the CS-MEO NPs was 130.7 nm, and the size of the CS-LEO NPs was 143.4 nm (as determined using Nanoparticle Tracking Analysis). The CS-NPs were incorporated into alginate hydrogels crosslinked with CaCl2. The hydrogels showed significant water retention capacity (>80%) even after the swollen sample was kept in the aqueous HCl solution (pH 1.2) for 4 h, indicating a good stability of the network. The hydrogels were tested (a) for their ability to absorb dietary lipids and (b) for their antimicrobial activity against Gram-positive and Gram-negative foodborne pathogens. The antimicrobial activity of the hybrid hydrogels was comparable to that of the widely used food preservative sodium benzoate 5% w/v. [ABSTRACT FROM AUTHOR]

Living tissues span a remarkable spectrum of modulus ranging from the level of Pa to GPa in a water‐rich environment. Constructing soft and hard materials that match the mechanics of tissues and researching mechanical transition in water, are beneficial for their biological applications. Here, using polyelectrolyte complex fiber as a model system and reinforcing the fiber by stepwisely introducing additional coordination and covalent bonds, this investigated that the water effect on mechanical transition behaviors. Alginate/chitosan fiber (AC fiber) has a single electrostatic bond and shows continuous mechanical transition containing a glassy state, rubbery state, and terminal relaxation (initial modulus lower than 10 MPa) in aqueous solution. Alginate/chitosan/calcium fiber (ACC fiber) has both electrostatic and coordination bonds, which shows the behavior of hard rubber (initial modulus 100 MPa) when water reaches equilibrium. Alginate/chitosan/calcium/polydopamine fiber (ACCP fiber) with triple bonds, including electrostatic, coordination, and covalent bonds, exhibits the behavior like ductile plastics in aqueous solution (initial modulus 1000 MPa). This work not only provides important insight into the toughening mechanism of polyelectrolyte complexes in water but also contributes to the preparation of tissue adaptive implantations. [ABSTRACT FROM AUTHOR]

This study aimed to assess pumpkin leaves as a protein source and determine the feasibility of these proteins to form complexes with alginate for the encapsulation of folic acid. Different isolation protocols, two based on isoelectric precipitation (one with thermal pretreatment and the other with alkali pre-extraction) and one based on stepwise precipitation with ammonium sulfate, were compared regarding the yield and structural properties of the obtained leaf protein concentrates (LPC). The highest purity of protein was achieved using the thermal-acid protocol and the salting-out protocol at 40% saturation. RuBisCO protein was detected by SDS-PAGE in all LPCs, except for the fractions obtained through salting-out at saturation level ≥ 60%. Complexation of the LPC solutions (1 mg/mL) and sodium alginate solution (10 mg/mL) was monitored as a function of LPC:alginate ratio (2:1, 5:1, and 10:1) and pH (2–8) by zeta-potential measurements and confirmed by FT-IR analysis. Based on the results, the strongest interaction between LPCs and alginate occurred at a pH between 2.20 and 2.80 and an LPC:alginate ratio of 10:1. Complexation resulted in particle yields of 42–71% and folic acid entrapment of 46–92%. The LPC-folic acid interactions elucidated by computational protein–ligand docking demonstrated the high potential of RuBisCO as a biocarrier material for folic acid. The in vitro release study in the simulated gastrointestinal fluids indicated that complexes would be stable in gastric conditions, while folic acid would be gradually released in the intestinal fluids. [ABSTRACT FROM AUTHOR]

Whey is the largest waste product of the cheese-making industry and the current methods of extracting the nutrients from it are costly and inefficient. This study assessed the feasibility of using crude polysaccharides to flocculate proteins from liquid whey waste. The flocculants used were a sugar kelp (Saccharina latissima) extract, as well as commercial seaweed polysaccharides, alginate and k-carrageenan, to recover proteins from the liquid whey waste. Physicochemical and functional parameters including protein content, protein recovery efficiency, mineral content, total phenolic content (TPC), antioxidant capacity, color, water- and oil-holding capacity, gelling capacity, foaming activity and stability, and emulsifying activity and stability were tested on the resulting flocculates. The yield of the dried flocculates by use of alginate, the sugar kelp polysaccharide extract (SKPE), and carrageenan were 1.66, 0.98, and 1.22 g/100 g of liquid whey with protein contents of 27.4%, 45.5%, and 37.5%, respectively. The protein recovery efficiency from the whey was 57.5%, 56.2%, and 57.9% using alginate, SKPE, and carrageenan, respectively. The alginate flocculate had the highest oil-holding capacity and foaming abilities while the carrageenan flocculate had the best gelling ability and the highest emulsifying activity and stability. TPC and antioxidant activity were highest in the SKPE flocculate. All three flocculates presented slightly different compositional and functional qualities, which could be used for a variety of products. This study showed that seaweed polysaccharides present a simple and effective way to extract protein from liquid whey waste while creating a functional and high-protein ingredient. [ABSTRACT FROM AUTHOR]

The use of materials from renewable sources instead of fossil fuels is a crucial step forward in the industrial transition toward sustainability. Among polysaccharides, alginate stands out as a versatile and eco‐friendly candidate due to its ability to form functional complexes with cations. This review provides an up‐to‐date and comprehensive description of alginate complexation with specific cations, focusing on how interaction forces can be harnessed to tailor the physicochemical properties of cation‐alginate‐based functional materials. Methodologies and approaches for the development and multiscale characterization of these materials are introduced and discussed. Alginate complexes with mono‐, di‐, tri‐, and tetravalent cations (namely Ag+, Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pb2+, UO22+, Cr3+, Fe3+, Al3+, Ga3+, Y3+, La3+, Ce3+, Nd3+, Eu3+, Tb3+, Gd3+, Zr4+, Th4+) are reviewed. Each cation is discussed individually, highlighting how it can uniquely influence the material properties thereby unlocking new potentials for the design of advanced functional materials. Key challenges and opportunities in applying these complexes across diverse fields, such as biomedicine, environmental remediation, food additives and supplements, flame retardants, sensors, supercapacitors, catalysis, and mechanical isolators are assessed, providing evidence of the transformative potential of cation‐alginate complexes for tackling global challenges and advancing cutting‐edge technologies. [ABSTRACT FROM AUTHOR]

Dealing with spinal cord injuries presents problematic due to multiple secondary mechanisms. Beyond primary concerns like paralysis and disability, complications including urinary, gastrointestinal, cardiac, and respiratory disorders, along with substantial economic burdens may occur. Limited research focuses on modeling and treating contusion and compression injuries. Tissue engineering emerges as an innovative treatment, targeting lesion pathophysiology. This study was evaluated implanting injectable biomaterials into injury-induced cavity before glial scar formation, avoiding tissue incisions and minimizing further damage. The efficacy of injectable alginate/thiolated chitosan hydrogel was investigated for acute spinal cord injury induced by Vanický method in Wistar rats. Three days post-injury, hydrogel was administrated through microinjection after laminectomy. After 60 days, the hydrogel group demonstrated notable motor function enhancement compared to the control by the BBB locomotor test (P < 0.05). However, no statistically significant differences were observed in MRI assessment concerning lesion severity. Stereological and histopathological evaluations revealed a reduction in vacuole volume and the presence of axon profiles within the scaffold (P < 0.05), alongside reduced infiltration of inflammatory and Gitter cells in the hydrogel group, although the latter was not statistically significant compared to the control. Thiolated chitosan/ alginate hydrogel implantation may be regarded as a promising treatment to enhance motor function by restraining destructive processes post-acute spinal cord injury. [ABSTRACT FROM AUTHOR]

Hydrogel foams are widely used in many applications such as biomaterials, cosmetics, foods, or agriculture. However, controlling precisely foam morphology (bubble size or shape, connectivity, wall and strut thicknesses, homogeneity) is required to optimize their properties. Therefore, a method is proposed here for generating, controlling, and characterizing the morphology of hydrogel foams from liquid foam templates: Using the example of Alginate‐CaHPO4‐based hydrogel foams, a highly controllable foaming process is provided by bubbling nitrogen through nozzles into the solution, which produces hydrogel foams with millimeter‐sized bubbles. A rheological characterization protocol of the foam's constituent material is first implemented and highlights the impact of the initial liquid foam properties and of the competition between the solidification kinetics and the foam aging mechanisms on the resulting morphology. X‐ray tomographic characterization performed on solidifying and solidified samples then demonstrates that by controlling the temporal evolution of the foam via its formulation, it is possible to tune the final morphology of the alginate foams. This method can be adapted to other hydrogel or polymer formulations, foam characteristics and length scales, as soon as solidification processes happen on timescales shorter than foam destabilization mechanisms. [ABSTRACT FROM AUTHOR]

The use of biopolymers in pharmaceuticals is well established, particularly for encapsulating biologically active compounds due to their beneficial properties. Alginate, widely recognized for its excellent encapsulation abilities, is the most commonly used biopolymer, while starch, typically known as insoluble dietary fiber, also serves as an effective agent for trapping and protecting compounds during processing, storage, and gastrointestinal transit. Sodium alginate–starch capsules with varying compositions were analyzed to develop metformin hydrochloride (MET) containing capsules with adequate physicochemical properties. In vitro testing with simulated gastrointestinal fluids showed that after 1 h, capsules with equal amounts of alginate and starch had a higher swelling ratio and better drug release behavior, despite lower MET entrapment efficiency compared to other formulations. Microstructural analysis revealed stability in simulated gastric fluids and solubility in simulated intestinal fluids, key factors in drug development. The results suggest that these biopolymeric compositions are highly resistant to gastric fluids and minimally soluble in the intestines, making them suitable for extended drug release. This research evaluates key technological parameters of a cost-effective encapsulation method for the controlled release of active substances, providing a versatile solution for pharmaceutical and biomedical applications. [ABSTRACT FROM AUTHOR]

Chlorothalonil (2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile, TPN, CAS: 1897-45-6) is a halogenated fungicide currently widely applied to a large variety of crops. Its carcinogenicity, embryo lethality, and high chronic oral toxicity in mammals, among other effects on a variety of organisms, has made its biodegradation of great interest. Chlorothalonil dehalogenase (Chd) from the bacterium Pseudomonas sp. CTN-3 offers a potential solution by catalyzing the first step in the degradation of chlorothalonil. Reported herein are active biomaterials of Chd when encapsulated in tetramethylorthosilicate (TMOS) gels using the sol–gel method (Chd/sol), alginate beads (Chd/alginate), and chitosan-coated alginate beads (Chd/chitosan). Both Chd/sol and Chd/chitosan increased protection from the endopeptidase trypsin as well as imparted stability over a pH range from 5 to 9. Chd/sol outperformed Chd/alginate and Chd/chitosan in long-term storage and reuse experiments, retaining similar activity to soluble Chd stored under similar conditions. All three materials showed a level of increased thermostability, with Chd/sol retaining >60% activity up to 70 °C. All materials showed activity in 40% methanol, suggesting the possibility for organic solvents to improve TPN solubility. Overall, Chd/sol offers the best potential for bioremediation of TPN using Chd. [ABSTRACT FROM AUTHOR]

Background: Adjuvants use several mechanisms to boost immunogenicity and to modulate immune response. The strength of adsorption of antigen by adjuvants can be a determinant factor for significant improvement of immunopotentiation. Methods: We expressed recombinant RBD‐FC in PichiaPink Strain 4 and examined the vaccination of mice by vaccine formulation with different adjuvants (sodium alginate and aluminum hydroxide, alone and together). Results: Sodium alginate significantly increased the immunogenicity and stability of RBD‐FC antigen, so RBD‐FC formulated with combined alginate and alum (AlSa) and sodium alginate alone showed higher antibody titer and stability. Immunogenicity of RBD‐FC:AlSa was determined by serological assays including direct enzyme‐linked immunosorbent assay (ELISA) and surrogate virus neutralization test (sVNT). High levels of IgGs and neutralizing antibodies were measured in serum of mice immunized with the RBD‐FC:AlSa formulation. On the other hand, cytokines IL‐10 and INF‐γ were severely accumulated in response to RBD‐FC:AlSa, and after 10 days, their accumulation was significantly declined, whereas IL‐4 showed the highest and the lowest accumulation in response to alum and alginate, respectively. Conclusions: Our data may suggest that combination of alum and sodium alginate has a better compatibility with RBD‐FC in vaccine formulation. [ABSTRACT FROM AUTHOR]

A new nanocomposite based on alginate microbeads impregnated with novel strontium–aluminum layered double hydroxide (Sr‐Al LDH) incorporated with choline chloride‐urea deep eutectic solvent (ChCl‐U DES) was introduced. The microbeads and LDH were characterized by adsorption/desorption isotherms, Fourier‐transform infrared spectroscopy, SEM, and x‐ray diffraction. The adsorbent was employed for determining penicillin G (PENG) using dispersive solid‐phase extraction prior to HPLC analysis. The extraction efficiency of the adsorbent, compared with that of unmodified alginate, showed a 2.5‐fold increase. Significant parameters, including elution conditions, sorbent composition and mass, adsorption time, and sample pH, were optimized. The LOD was 0.4 µg kg−1, and the linear range was 1.4–500 µg kg−1. The LOQ (1.4 µg kg−1) was lower than the established maximum level for PENG by the European Union (4 µg kg−1). Enrichment factor and synthesis reproducibility were also investigated. The method's accuracy was evaluated through PENG analysis in dairy products and water, with recoveries of 81%–107% (RSDs < 7.6%). The procedure's greenness was assessed using the Analytical Eco‐scale and achieved excellent green credentials. To the best of our knowledge, this is the first report on the synthesis and application of a novel alginate composite for the extraction of PENG from dairy and water samples. [ABSTRACT FROM AUTHOR]

Identification of suitable polymeric materials to fabricate microneedles (MNs) for the collection of interstitial fluid (ISF) is a challenge. Here, characterization of different carrageenan‐biopolymer composites for MN patch fabrication intended for ISF collection is reported. Systematic oscillatory rheological studies of composites containing iota‐carrageenan mixed with alginate, gelatin, or pectin are performed to determine the linear viscoelastic region, gel point, tan delta, complex viscosity, and flow transition index. A polynomial equation is derived by relating flow transition index of biopolymer composites and compression strength of fabricated MNs. The biopolymer composite of iota‐carrageenan and gelatin at 2% and 14%, respectively, and CaCl2 crosslinker (80 mm) shows the greatest compression strength sufficient for MNs insertion into the excised porcine skin. MNs swell up on application in an agarose gel model and the ex vivo excised porcine skin model to collect 36 ± 5 and 14 ± 1 µL of fluid within 10 min, respectively. Taken together, it is demonstrated that rheological analysis can be performed to select suitable polymer composites that possess sufficient strength for the skin insertion and swellability for ISF collection. [ABSTRACT FROM AUTHOR]

Lactose intolerance affects ∼65% of the global adult population, leading to the demand for lactose-free products. The enzyme β-galactosidase (βG) is commonly used in the industry to produce such products, but its recovery after lactose hydrolysis is challenging. In this scenario, the study aims to encapsulate βG within capsules, varying in dimensions and wall materials, to ensure their suitability for efficient industrial recovery. The enzyme βG was encapsulated through ionic gelation using alginate and its blends with pectin, maltodextrin, starch, or whey protein as wall materials. The capsules produced underwent evaluation for encapsulation efficiency, release profiles, activity of the βG enzyme, and the decline in enzyme activity when reused over multiple cycles. Alginate at 5% wt/vol concentrations, alone or combined with polymers such as maltodextrin, starch, or whey protein, achieved encapsulation efficiencies of ∼98%, 98%, 80%, and 88%, respectively. The corresponding enzyme recovery rates were 34%, 19%, 31%, and 48%. Capsules made with an alginate-pectin blend exhibited no significant hydrolysis and maintained an encapsulation efficiency of 79%. Encapsulation with alginate alone demonstrated on poor retention of enzyme activity, showing a loss of 74% after just 4 cycles of reuse. Conversely, when alginate was mixed with starch or whey protein concentrate, the loss of enzyme activity was less than 40% after 4 reuses. These results highlight the benefits of combining encapsulation materials to improve enzyme recovery and reuse, offering potential economic advantages for the dairy industry. The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. [ABSTRACT FROM AUTHOR]

Coprinus comatus is an edible mushroom and its fermented product possesses antioxidant activity. In this study, to further enhance the antioxidant activity and improve the reusability of the strain, calcium alginate hydrogel was used as the carrier for embedding and immobilizing Coprinus comatus. The effects of CaCl2 concentration, sodium alginate concentration, microsphere diameter, and the amount of magnetic particle on the antioxidant activity of fermented products were investigated. The results showed that the magnetic immobilized microsphere prepared by 2.50% CaCl2, 2.00% sodium alginate and 0.50% Fe3O4 had the best fermentation antioxidant activity (EC50 was 0.43 ± 0.01 mg/mL) when the diameter was 5 mm, which increased by 24.56% compared to the initial activity. Besides, the microsphere showed strong reusability, the antioxidant activity was still better than the free strain after being used five times. This study not only enhanced the antioxidant activity of Coprinus comatus fermented product through immobilization, but also provided an effective method for microbial fermentation. [ABSTRACT FROM AUTHOR]

Changes in the physical, biochemical, and microbiological properties of Pangasius mince incorporated with 2% (w/w) sodium alginate and salt were evaluated for 120 days under frozen conditions (−20 °C). The TBARS (0.03–0.62 mg MDA/kg) and free fatty acid (FFA) (<1 mg oleic acid/100 g) were found to be significantly lower in the alginate-treated sample (T2) than in the control mince (C) and salt-added mince sample (T1). Better visual appearance, higher water retention, less moisture reduction (only 1.5%) along with lower total volatile base nitrogen (TVBN) (10–17 mg N/100 g) and TVC (<4 log cfu/g) were evident in T2 throughout the storage period than in T1 and control. [ABSTRACT FROM AUTHOR]

Nowadays, hydrogel has a wide range of applications, such as in the biomedical field, due to its excellent biocompatibility. Hydrogel may be synthesized using biomaterials that are abundantly found in the natural environment. This research involved the synthesis of a hydrogel using sugar palm starch as the base material, but hydrogel made from starch has lower chemical and physical properties. To enhance its chemical, physical, and mechanical properties, alginate and chitosan were incorporated as reinforcing agents because they can form strong gels, which might be due to the interaction of the amino (-NH2) group from chitosan and carboxyl (-COO-) group from alginate with the hydroxyl (-OH) group from starch. The objective of the study was to determine the best reinforcing agents for the formation of two sugar palm-based hydrogel formulations: sugar palm starch/chitosan hydrogel and sugar palm starch/alginate hydrogel, with good chemical, physical and mechanical properties, such as thickness, swelling ratio, water contact angle, functional group, mechanical properties including tensile strength, and elongation at break, surface morphology images, and thermal properties. The result showed that the hydrogel composed of sugar palm starch and chitosan as reinforcing agent exhibited better characteristics than alginate, indicating their potential for biomedical application as shown by its result in swelling ratio with value of 67.81±0.11%, average tensile strength of 0.113±0.04 MPa and elongation at a break value of 37.83±7.0%. [ABSTRACT FROM AUTHOR]

The topical therapy with rifampicin (RF)-based formulations is beneficial for treating postoperative wound infections and to accelerate healing. Despite recent research highlighting the antibiotic's significant anti-inflammatory properties, limited topical wound healing products are currently available. The present study aimed to prove that the newly synthesized nanoparticles based on grafted alginate and poly(N-vinylcaprolactam) (pNVCL) and poly-lactic-co-glycolic acid (PLGA) contribute to the healing process of a wound. The methods used were at first the synthesis of the copolymer of alginate and pNVCL via grafting from technique and radical polymerization followed by water-in-oil-in water (W/O/W) emulsification; as oil phase PLGA dissolved in dichloromethane (DCM) was used. The formed nanoparticles were than characterized. The loaded RF was determined to be 160 µg/mL for a 20 mg formulation and within a four-hour time frame approximately 10% of the total loaded amount was released. The inhibitory concentrations (IC50) were 192.1 µg/mL for the nanoparticle, 208.8 µg/mL for pure rifampicin, and 718.1 µg/mL for the rifampicin-loaded nanoparticles. Considering the double role rifampicin was used for, the result was considered satisfactory in the way that these formulations could be used predominantly for postoperative wound irrigation in order to avoid infections and to improve healing. [ABSTRACT FROM AUTHOR]

The probiotic bacterium Bifidobacterium animalis subsp. lactis BB-12 (BB-12) was encapsulated in two composites, alginate/agar and alginate/agar/casein. The network structure and physicochemical properties of these composites are influenced by complex interactions, including hydrogen bonding, electrostatic forces between biopolymers, calcium ions, and the encapsulated bacteria. The composites demonstrated a granular surface, with the granules being spatially oriented on the alginate/agar/BB-12 surface and linearly oriented on the alginate/agar/casein/BB-12 surface. They possess a highly organized microparticle structure and exhibit viscoelastic solid-like behavior. The alginate/agar/BB-12 composite showed higher storage modulus, shear stress, and shear strain values, indicating enhanced stability in various physical environments. Both composites displayed good thermal stability, aligning with their rheological properties, confirming their well-ordered structures. Despite differences in composite structures, the release mechanism of bacteria is governed by Fickian diffusion through the composite matrix. Based on physicochemical properties, the alginate/agar/casein composite is recommended for dairy product fermentation, while the alginate/agar composite seems more suitable for oral use. These findings provide new insights into the interactions between bacterial cultures and alginate composite ingredients. [ABSTRACT FROM AUTHOR]

Relatively little is known about enzymes with broad substrate spectra, leading to limited applications and progress. Herein, we elucidate Aly16-1 of Streptomyces sp. strain CB16 as a novel multifunctional member of the eighth polysaccharide lyase (PL8) family, although it shared few sequence identities with the characterized enzymes. The recombinant enzyme rAly16-1 showed lyase activities against several acidic polysaccharides, including many glycosaminoglycan types, xanthan, and alginate. It was mannuronate (M)-preferred, endolytic, and optimal at 50 °C and pH 6.0. The smallest substrate was an ∆M-terminal (∆: unsaturated monosaccharide) trisaccharide, and the minimal product was ∆. In the final alginate digestions by rAly16-1, the fractions larger than disaccharides were ∆G-terminal (G: guluronate), while the disaccharides were mainly ∆M, showing an oligosaccharide-yielding property under the succession law. However, when degrading various oligosaccharides, rAly16-1 continued producing ∆M from the non-reducing end even when the substrates increased their sizes, quite different from the elucidated alginate lyases with variable alginate-degrading modes. Thus, co-determined by its M-preference, Aly16-1 is novel for its ∆M-yielding property in oligosaccharide preparations. Additionally, rAly16-1 can be applied in sequencing unsaturated trisaccharides, whether ∆M- or ∆G-terminal. This study provides novel insights into the characteristics and applications of a multifunctional enzyme within the PL8 family for resource explorations. [ABSTRACT FROM AUTHOR]

Background/Objectives: This study focuses on the development and evaluation of novel alginate–poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride (PMETAC) microcapsules for encapsulating pancreatic islets to address insulin deficiency in diabetes. Methods: In previous research, we fabricated and characterized PMETAC microcapsules, evaluating their stability and permeability in vitro. This study further probes the capsules in vivo, focusing on the functional activity of the encapsulated islets post-transplantation, their viability extension, and the assessment of the immunoprotective, antifibrotic properties, and biostability of the capsules. Results: Rabbit-derived islets were encapsulated and transplanted into diabetic rats. The encapsulated islets maintained insulin secretion for up to 90 days, significantly longer than non-encapsulated ones, which ceased functioning after 7 days. Histological analysis demonstrated high biocompatibility of the PMETAC coating, resulting in minimal fibrotic overgrowth around the capsules. Conclusions: The study highlights the critical role of immunoprotection and the tendency to reduce fibrosis in prolonging islet function. These findings suggest that PMETAC-coated capsules offer a promising solution for cell-based therapies in diabetes by improving graft longevity and reducing fibrotic overgrowth. [ABSTRACT FROM AUTHOR]

Currently, bacterial inoculant technology focuses on improving long-term storage conditions to ensure adequate rhizobia numbers and their effectiveness as plant growth promoters. This study aimed to investigate whether storage at 4 °C for four years of alginate beads immobilizing Bradyrhizobium sp. SEMIA6144 maintains bacterial vitality, efficacy in growth promotion, and ability to establish early interactions with Arachis hypogaea L. The recovery of viable SEMIA6144 cells decreased over time (10% at six months, 1% at one year, and 0.01% at four years), while cell vitality remained high at 94.1%, 90.2%, and 93.4%, respectively. The unsaturated/saturated fatty acid ratio declined during storage, reducing membrane fluidity and metabolic activity. Mobility and root adhesion of SEMIA6144 decreased after one and four years. However, growth promotion in peanuts inoculated with SEMIA6144 beads was observed through increased biomass, total chlorophyll, leaf number, leaf area, and decreased chlorophyll fluorescence compared to non-inoculated plants. Although nodulation was low in plants inoculated with four-year-old beads, leghemoglobin levels were maintained. These results demonstrate that Bradyrhizobium sp. SEMIA6144 can be stored for four years in alginate beads at 4 °C, maintaining its vitality and ability to establish a symbiosis that stimulates early peanut growth. Understanding these physiological changes could be valuable for the future improvement of long-lasting inoculants. [ABSTRACT FROM AUTHOR]

Nanostructured lipid carriers (NLC) have low storage and gastrointestinal stability, limiting their applicability. The work aimed to elevate the stability and behaviour of NLC in the alimentary tract by creating an alginate bead. Through the extrusion dropping procedure, Resveratrol (RES)-loaded NLC were efficiently integrated into alginate beads. The incorporation had no significant impact on the particle size, morphology, or inner structure of NLC, as assessed using DLS (Dynamic Light Scattering), SEM (Scanning Electron Microscopy), Differential Scanning Calorimetry (DSC) and FT-IR (Fourier Transform Infra-Red). Incorporating NLC into alginate beads improves its physical stability compared to dispersion of NLC as well as NLC-Sol. An in vitro release investigation found that the NLC-alginate beads released RES more slowly than optimized NLC formulation (RES-NLCs-opt) and NLC-alginate sol. Research on simulated in vitro digestive models revealed that just a small amount of integrated NLC may permeate stomach fluid due to its tiny size. The slow diffusion of NLC from alginate to intestinal fluid prevented aggregation and allowed for gentle hydrolysis of the lipid matrix. Incorporating NLC in alginate beads shows promise for improving stability, modifying gastrointestinal behaviour, and controlling release throughout the process of digestion. [ABSTRACT FROM AUTHOR]

The good combination of high strength and high toughness is a long‐standing challenge in the design of robust biomaterials. Meanwhile, robust biomaterials hardly perform fast and significant mechanical property changes under the trigger of light at room temperature. These limit the application of biomaterials in some specific areas. Here, photoresponsive alginate fibers are fabricated by using the designed azobenzene‐containing surfactant as flexible contact point for cross‐linking polysaccharide chains of alginate, which gain high mechanics through reinforced plastic strain and photo‐modulating mechanics through isomerization of azobenzene. By transferring molecular motion into macro‐scale mechanical property changes, such alginate fibers achieve reversible photo‐modulations on the mechanics. Their breaking strength and toughness can be photo‐modulated from 732 MPa and 112 MJ m−3 to 299 MPa and 27 MJ m−3, respectively, leading to record high mechanical changes among the developed smart biomaterials. With merits of good tolerance to pH and temperature, fast response to light, and good biocompatibility, the reported fibers will be suitable for working in various application scenarios as new smart biomaterials. This study provides a new design strategy for gaining highly‐strong and highly‐tough photoresponsive biomaterials. [ABSTRACT FROM AUTHOR]

Microfluidics cell encapsulation offers a way to mimic a 3D microenvironment that supports cell growth and proliferation, while also protecting cells from environmental stress. This technique has found extensive applications in tissue engineering and cell therapies. Several studies have demonstrated the advantages of graphene oxide (GO) as an osteogenic inducer; however, the significance of GO on stem cell fate in the single-cell state is still unclear. Here, a microfluidics-based approach is developed for continuous encapsulation of mesenchymal stem cells (MSCs) at the single-cell level using alginate microgels. So, single-layer graphene oxide (slGO) nanosheet is used to be encapsulated inside the alginate droplets. The results of AFM and SEM show that slGO can increase the roughness and reduce the stiffness of alginate hydrogels. The Young's modulus of the alginate and alginate-slGO was obtained as 1414 kPa and 985.9 kPa, respectively. Live/dead assay and fluorescence microscopy images illustrate that slGO can maintain the viability and proliferation of microencapsulated hBMSCs. The obtained results show that slGO increases the mineralization of the encapsulated hBMSCs, so that microgels containing hBMSCs gradually became opaque during 21 days of culture. RT-qPCR results indicate that the expression of OCN, Runx2, and ALP in the alginate-slGO microgels is significantly higher than in the alginate microgels. The expression of OCN and Runx2 in the alginate-slGO microgels is 4.27 and 5.87-fold higher than in the alginate microgels, respectively. It can be concluded that low doses of slGO nanosheets have the potential to be utilized in the development of tissue engineering and bone regeneration. This finding offers a new method for creating injectable tissue transplants that are minimally invasive. [ABSTRACT FROM AUTHOR]

Most of Earth's biomass is composed of polysaccharides. During biomass decomposition, polysaccharides are degraded by heterotrophic bacteria as a nutrient and energy source and are thereby partly remineralized into CO2. As polysaccharides are heterogeneously distributed in nature, following the colonization and degradation of a polysaccharide hotspot the cells need to reach new polysaccharide hotspots. Even though many studies indicate that these degradation-dispersal cycles contribute to the carbon flow in marine systems, we know little about how cells alternate between polysaccharide degradation and motility, and which environmental factors trigger this behavioral switch. Here, we studied the growth of the marine bacterium Vibrio cyclitrophicus ZF270 on the abundant marine polysaccharide alginate, both in its soluble polymeric form as well as on its breakdown products. We used microfluidics coupled to time-lapse microscopy to analyze motility and growth of individual cells, and RNA sequencing to study associated changes in gene expression. We found that single cells grow at reduced rate on alginate until they form large groups that cooperatively break down the polymer. Exposing cell groups to digested alginate accelerates cell growth and changes the expression of genes involved in alginate degradation and catabolism, central metabolism, ribosomal biosynthesis, and transport. However, exposure to digested alginate also triggers cells to become motile and disperse from cell groups, proportionally increasing with the group size before the nutrient switch, and this is accompanied by high expression of genes involved in flagellar assembly, chemotaxis, and quorum sensing. The motile cells chemotax toward polymeric but not digested alginate, likely enabling them to find new polysaccharide hotspots. Overall, our findings reveal cellular mechanisms that might also underlie bacterial degradation-dispersal cycles, which influence the remineralization of biomass in marine environments. [ABSTRACT FROM AUTHOR]

The development of injectable hydrogels for soft tissue regeneration has gained significant attention due to their minimally invasive application and ability to conform precisely to the shape of irregular tissue cavities. This study presents a novel injectable porous scaffold based on natural polymers that undergoes in situ crosslinking, forming a highly resilient hydrogel with tailorable mechanical and physical properties to meet the specific demands of soft tissue repair. By adjusting the formulation, we achieved a range of stiffness values that closely mimic the mechanical characteristics of native tissues while maintaining very high resilience (>90%). The effects of gelatin, alginate, and crosslinker concentrations, as well as porosity, on the hydrogel's properties were elucidated. The main results indicated a compression modulus range of 2.7–89 kPa, which fits all soft tissues, and gelation times ranging from 5 to 30 s, which enable the scaffold to be successfully used in various operations. An increase in gelatin and crosslinker concentrations results in a higher modulus and lower gelation time, i.e., a stiffer hydrogel that is created in a shorter time. In vitro cell viability tests on human fibroblasts were performed and indicated high biocompatibility. Our findings demonstrate that these injectable hydrogel scaffolds offer a promising solution for enhancing soft tissue repair and regeneration, providing a customizable and resilient framework that is expected to support tissue integration and healing with minimal surgical intervention. [ABSTRACT FROM AUTHOR]

Using a syringe, the precast gel solution—which included acrylamide, sodium alginate, and modified titanium dioxide nanofibers—was extruded into the CaCl 2 solution to create the sodium alginate first network. The second network of polyacrylamide(PAM) was subsequently created by photocatalysis. Ultimately, the alginate/PAM/TiO 2 NF@PAM composite hydrogel improved by the inorganic phase was produced. It has mechanical properties with a tensile ratio of 166% and a tensile strength of 1.13 Mpa. [Display omitted] • Alginate/polyacrylamide/modified TiO 2 nanofiber (Alginate/PAM/TiO 2 NF@PAM) composite hydrogel was successfully designed and synthesized. • The three toughening strategies of dual network, construction of oriented structure, and nanophase doping were successfully combined. • Alginate/PAM/TiO 2 NF@PAM showed a tensile ratio of (165.51 ± 4.93)% and a maximum tensile strength of (1130.97 ± 67.39) kpa. The design and construction of high strength hydrogels is a widely discussed topic in hydrogel research. In this study, we combined three toughening strategies, including dual network, oriented structure construction and nanophase doping, to develop an alginate/polyacrylamide (PAM)/modified titanium dioxide fiber (TiO 2 NF@PAM) dual network composite hydrogel prepared via syringe. The effects of different preparation methods, AM/Alginate ratios, inorganic doping phases and TiO 2 NF@PAM/AM ratios on the mechanical properties of composite hydrogels were investigated. The study found that the alginate hydrogel prepared by syringe exhibited superior axial orientation and achieved a tensile strength of (1091 ± 46) kPa. And the composite hydrogel doped with 0.2 wt% TiO 2 NF@PAM had a tensile strength of (1006 ± 64) kPa, which was higher than that of the composite hydrogel doped with 0.2 wt% TiO 2 nanoparticles (976 ± 66) kPa. The highest tensile strength (1120 ± 67) kPa and elongation at break (182 ± 8) % were achieved when the ratio of TiO 2 NF@PAM/AM was 0.6 wt%. The force applied to the gel solution in the syringe affects the orientation of the polymer chains and TiO 2 NF@PAM within the gel, which subsequently impacts the mechanical properties of the hydrogel. Therefore, we further investigated the mechanical properties of composite hydrogels under varying propulsion speeds, syringe diameters, and syringe lengths. It was observed that the gel solution's shear strength increased as the syringe diameter decreased. The resulting composite hydrogels were better oriented and had improved mechanical properties. The composite hydrogels' tensile strength peaked at (1117 ± 47) kPa when the syringe advance rate was between 1–7 mL/min. The mechanical properties of the hydrogels were optimal when the syringe length was 30 mm, with a maximum tensile strength of (1131 ± 67) kPa and a tensile ratio of (166 ± 5) %. This study demonstrates the viability of integrating three distinct strengthening methodologies to generate hydrogels of considerable strength. Furthermore, the Alginate/PAM/TiO 2 NF@PAM composite hydrogels possess remarkable potential as adaptable, wearable sensors due to their exemplary mechanical properties, knittability, and conductivity. [ABSTRACT FROM AUTHOR]