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ZIF-8, a metal–organic framework that has significant benefits such as a substantial specific surface area, abundant active sites, and high porosity, has extensive application in environmental remediation. However, ZIF-8 is powdery and easily agglomerated, making it difficult to separate ZIF-8 from aqueous solutions and thus limiting its practical application in wastewater treatment. In this work, sodium alginate was chosen as a gel matrix, and CaCl2 as a cross-linking agent to form a calcium cross-linked MOF gel material (ZIF-8/SA). The batch adsorption investigations demonstrated that the saturated adsorption capacities of ZIF-8/SA in single Mn2+ pollution solution and Mn–Cu–Cd composite pollution solution are 179.86 mg g−1 and 101.86 mg g−1, respectively. Specifically, the adsorption of Mn2+ followed the Langmuir model and exhibited monomolecular layer adsorption. Furthermore, the adsorption of Cu2+ and Cd2+ followed the quasi-first-order kinetic model, which is primarily physical adsorption. The adsorption order of ZIF-8/SA for contaminants in the adsorption process is as follows: Cu2+ > Cd2+ > Mn2+. The SEM-EDS, FT-IR, and XPS studies revealed that the adsorption mechanism of ZIF-8/SA mostly involves ion exchange, coordination of carboxyl/hydroxyl/amino groups, and electrostatic attraction. To summarize, the experimental findings of this study demonstrate that the synthetic ZIF-8/SA hydrogel has promising applications for practical pollution treatment. [ABSTRACT FROM AUTHOR]

Purpose: Removal of the current calcium alginate packing materials to the middle meatus in endoscopic sinus surgery (ESS) is usually accompanied by discomfort or pain owing to the hard and brittle nature of these materials. Plus moist HS-W® is a new calcium alginate packing material released in 2022 developed to overcome this issue by changing the uronic acid component. We aimed to compare the discomfort/pain during the removal of Plus moist HS-W® with Kaltostat®, as well as their suitability as packing materials in ESS. Methods: Kaltostat® and Plus moist HS-W® were used as packing materials in 22 and 21 patients who underwent ESS in 2021 and 2022, respectively. Patients were asked to rate the pain during the packing removal 10 days after ESS using the Numerical Rating Scale (NRS). The ratio of residual packing materials, number of suctions (insertions/extractions of the suction cannula), and time required to remove packing materials were measured. Postoperative complications such as hemorrhage, local infection, lateralization of the middle turbinate, and synechia of the middle meatus were also evaluated. Results: The Plus moist HS-W® group exhibited significantly lower NRS pain scores, a lower ratio of residual packing materials, a reduced number of suctions, and a shorter time required to remove the packing. No obvious postoperative complications occurred in both groups except for one suspicious case of a slight infection in the Kaltostat® group. Conclusion: Compared with Kaltostat®, Plus moist HS-W®, characterized by better gelatinization than Kaltostat®, benefits patients by minimizing discomfort/pain during removal. Level of evidence: Level 3. [ABSTRACT FROM AUTHOR]

The flotation behavior of apatite, a main mineral source of phosphorus, is strongly affected by the dissolved ionic species from gangue minerals. In this study, the effect of calcium ions on the fluorapatite flotation using the extracted sodium alginate E.SA depressant was investigated through microflotation tests, adsorption experiments, zeta potential measurements, and FTIR analyses. Although the amount of NaOL collector adsorbed on fluorapatite increased with increasing calcium concentrations, microflotation results reveal that adding calcium ions could deteriorate the fluorapatite recovery. More significant depression of fluorapatite could be achieved when Ca2+ and E.SA co-existed in the system. Zeta potential measurements and FTIR analyses showed that the addition of Ca2+ hardly affected the adsorption of E.SA onto fluorapatite surface, which can be due to the formation and precipitation of calcium alginate. In contrast, NaOL remained weakly adsorbed on the fluorapatite surface even the presence of Ca2+ and E.SA. [ABSTRACT FROM AUTHOR]

Textile effluents containing toxic dyes must be treated effectively before discharge to prevent adverse environmental impacts. Traditional physical and chemical treatment methods are costly and generate secondary pollutants. In contrast, biological treatment is a more suitable, clean, versatile, eco-friendly, and cost-effective technique for treating textile effluent. It is well established that indigenous microbial populations present in effluents can effectively degrade toxic dyes. In this regard, Achromobacter xylosoxidans DDB6 was isolated from the effluent sample to decolorize crystal violet (CV), Coomassie brilliant blue (CBB), and alizarin red (AR) by 67.20%, 28.58%, and 20.41%, respectively. The growth parameters of A. xylosoxidans DDB6 in media supplemented with 100 ppm of various dyes were determined using the modified Gompertz growth model. The immobilized cells in calcium alginate beads showed apparent decolorization rate constant of 0.27, 0.18, and 0.13 h−1 for CV, CBB, and AR, respectively. The immobilized cells in a packed bed reactor with an optimum flow rate of 0.5 mL/min were used to treat 100 ppm of CV with a percentage decolorization of 79.47% after three cycles. Based on the findings, A. xylosoxidans DDB6 could be effectively used for decolorization of various dyes. [ABSTRACT FROM AUTHOR]

Tetracycline (TC) is a common antibiotic; when untreated TC enters the environment, it will cause a negative impact on the human body through the food chain. In the present study, MnO2/MCM-41@Fe3O4 (FeMnMCM) prepared using a hydrothermal and redox method and Camellia oleifera shell-activated carbon (COFAC) prepared through alkali activation were encapsulated using alginate (ALG) and calcium chloride as a cross-linking matrix to give the composite beads COFAC–FeMnMCM–ALG. The resultant COFAC–FeMnMCM–ALG composite beads were then carefully characterized, showing a high immobilization of MnO2/MCM-41@Fe3O4, with porous COFAC as an effective bioadsorbent for enriching the pollutants in the treated samples. These bead catalysts were subsequently applied to the oxidative degradation of TC in a Fenton oxidation system. Several parameters affecting the degradation were investigated, including the H2O2 concentration, catalyst dosage, initial TC concentration, and temperature. A very high catalytic activity towards the degradation of TC was demonstrated. The electron paramagnetic resonance (EPR) and quenching results showed that ·OH and ·O2− were generated in the system, with ·OH as the main radical species. In addition, the COFAC–FeMnMCM–ALG catalyst exhibited excellent recyclability/reusability. We conclude that the as-prepared COFAC–FeMnMCM–ALG composite beads, which integrate MnO2 and Fe3O4 with bioadsorbents, provide a new idea for the design of catalysts for advanced oxidation processes (AOPs) and have great potential in the Fenton oxidation system to degrade toxic pollutants. [ABSTRACT FROM AUTHOR]

Double‐network hydrogels based on calcium alginate are extensively exploited. Unfortunately, their low strength and unstable constitution to open environments limit their application potential. Herein, a new type of double‐network organohydrogel (OHG) is proposed. By solvent exchange, a stable physical network is established based on dimethyl sulfoxide (DMSO)‐alginate in the presence of a polyacrylamide network. The DMSO content endows tunable mechanical properties, with a maximum tensile strength of ≈1.7 MPa. Importantly, the OHG shows much better environmental stability compared to the conventional double‐network hydrogels. Due to the reversible association of hydrogen bonds, the OHG possesses some unique properties, including free‐shapeability, shape‐memory, and self‐adhesion, that offers several promising ways to utilize alginate‐based gels for wide applications. [ABSTRACT FROM AUTHOR]

To combat climate change, one approach is to manufacture products from biomass-fungi composite materials instead of petroleum-based plastics. These products can be used in packaging, furniture, and construction industries. A 3D printing-based manufacturing method was developed for these biomass-fungi composite materials, eliminating the need for molds, and enabling customized product design. However, previous studies on the 3D printing-based method showed significant shrinkage of printed samples. In this paper, an approach is proposed to reduce the shrinkage by incorporating ionic crosslinking into biomass-fungi composite materials. This paper reports two sets of experiments regarding the effects of sodium alginate (SA) and calcium chloride (CaCl2) on fungal growth and fungal viability. The first set of experiments was conducted using Petri dishes with fungi isolated from colonized biomass-fungi material and different concentrations of SA and CaCl2. Fungal growth was measured by the circumference of fungal colonies. The results showed that concentrations of SA and CaCl2 had significant effects on fungal growth and no fungal growth was observed on Petri dishes with 15% CaCl2. Some of these Petri dishes were also observed under confocal microscopy. The results confirmed the differences obtained by measuring the circumference of fungal colonies. The second set of experiments was conducted using Petri dishes with biomass-fungi mixtures that were treated with different concentrations of SA and exposure times in a CaCl2 (crosslinking) solution. Fungal viability was measured by counting colony-forming units. The results showed that the addition of the SA solution and exposure times in the crosslinking solution had statistically significant effects on fungal viability. The 2SA solution was prepared by dissolving 2 g of SA in 100 mL of water, the 5SA solution was prepared by dissolving 5 g of SA in 100 mL of water, and the crosslinking solution was prepared by dissolving 5 g of CaCl2 in 100 mL of water. The results also showed that fungal viability was not too low in biomass-fungi mixtures that included 2SA solution and were exposed to the crosslinking solution for 1 min. [ABSTRACT FROM AUTHOR]

A microfluidic strategy of smart calcium alginate (CA) capsules is presented to immobilize Pseudomonas aeruginosa to treat oil slicks effectively. The capsule wall is embedded with poly (N‐isopropyl acrylamide) sub‐microspheres as thermo‐responsive switches. CA capsules, with a diameter of 3.26 mm and a thin wall thickness about 12.8 μm, have satisfying monodispersity, cavity structure, and dense surface structures. The capsules possess excellent encapsulation of bacteria, which are fixed in a restricted space and become more aggregated. It overcomes the disadvantages of a long fermentation production cycle, easy loss of bacteria, and susceptibility to shear effect. The smart CA capsules immobilized with bacteria treat model wastewater containing soybean oil or diesel and display favorable fermentation ability. The capsules can effectively treat oil slicks with high concentration, and it is an economical way for processing oily wastewater. Practitioner Points: A thermo‐responsive calcium alginate capsule was prepared by microfluidic strategy.Pseudomonas aeruginosa is environmentally friendly in treating oil slicks.The capsules, immobilized bacteria, treat oil slicks effectively.This study provides an economical way for processing different oily water. [ABSTRACT FROM AUTHOR]

BACKGROUND: Calcium alginate gels are widely used to encapsulate active compounds. Some characteristic parameters of these gels are necessary to describe the release of active compounds through mechanistic mathematical models. In this work, transport and kinetics properties of calcium alginate gels were determined through simple experimental techniques. RESULTS: The weight‐average molecular weight (M¯w = 192 × 103 Da) and the fraction of residues of α‐l‐guluronic acid (FG = 0.356) of sodium alginate were determined by capillary viscometry and 1H‐nuclear magnetic resonance at 25 °C, respectively. Considering the half egg‐box model, both values were used to estimate the molecular weight of calcium alginate as Mg = 2.02 × 105 Da. An effective diffusion coefficient of water (Deff,w = 2.256 × 10−9 m2 s−1) in calcium alginate was determined using a diffusion cell at 37 °C. Finally, a kinetics constant of depolymerization (km = 9.72 × 10−9 m3 mol−1 s−1) of calcium alginate was obtained considering dissolution of calcium to a medium under intestinal conditions. CONCLUSION: The experimental techniques used are simple and easily reproducible. The obtained values may be useful in the design, production, and optimization of the alginate‐based delivery systems that require specific release kinetics of the encapsulated active compounds. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Purpose: Sodium alginate (Na-Alg) is a natural polysaccharide with a rich and renewable production that is widely used in the food, pharmaceutical and daily necessities industries, among other fields. The purpose of this study is to obtain a green and degradable shape memory material, calcium alginate (Ca-Alg) film was prepared and the mechanical properties, the shape memory effect of the film were investigated and confirmed. Design/methodology/approach: The Ca-Alg films were prepared by Na-Alg, calcium chloride (CaCl2) solution, and flow extension method. Dissolve sodium alginate powder, remove bubbles, pour into petri dish, dry at 60°C, add calcium chloride solution cross-linking and finally dry naturally. The effect of CaCl2 solution concentration on the mechanical properties of the films were investigated and discussed by universal tensile tester. The shape memory behavior and degradation performance of thin films were verified and studied by the fold-deploy shape memory test and soil embedding method, respectively. Findings: The Ca-Alg films exhibited good mechanical and shape memory properties, with a 72.2% shape memory fixity ratio and a 92.3% shape memory recovery ratio, respectively. For a period of 120 days, the film treated with a 6 wt% CaCl2 solution degraded at a rate of approximately 53%. Research limitations/implications: Shape memory polymers (SMPs) as intelligent materials are an important research direction for the development of modern high-tech materials. On the other hand, plastic pollution is a major problem today; as a result, preparing green degradable SMPs is essential. Originality/value: This study synthesized transparent and degradable shape memory Ca-Alg films using Na-Alg and CaCl2 solution and the flow extension method. [ABSTRACT FROM AUTHOR]

Calcium alginate gel microspheres exhibiting pH response release characteristics were prepared, and utilizing Bovine serum albumin (BSA) to evaluate drug release performance. Hydrogels composed of gelatin (GL) and sodium alginate oxide (NALO), with varying ratios (7:3; 4:1; 3:2) were prepared by controlling their composition. Scanning electron microscopy (SEM) and a microplate reader (ELIASA) were used to characterize the microspheres' microstructure and in vitro BSA release behavior, respectively. The results demonstrated that, under acidic conditions, the BSA release was slower than in neutral conditions. The hydrogels' physical and chemical properties were analyzed using optical microscopy, Fourier transform infrared spectroscopy (FTIR), swelling experiments and mechanical testing of the hydrogels and microsphere loaded hydrogels. The results showed that a GL to NALO ratio of 7:3 increased the swelling degree, while a 4:1 ratio optimized the mechanical characteristics. The study concluded that the microsphere-loaded hydrogels exhibited significant potential for human drug delivery applications. [ABSTRACT FROM AUTHOR]

Rugulopteryx okamurae (RO) is an invasive brown seaweed that causes severe environmental problems in the Mediterranean Sea. This work proposed an extraction method that enables their use as a raw material for producing sodium alginate. Alginate was successfully extracted from this invasive seaweed, with its gelling performance in the presence of Ca2+ ions comparable to existing commercial alginates. The mannuronic acid (M)-to-guluronic (G) acid ratio in the 1H-NMR profile indicated a higher percentage of G in the RO-extracted alginate, which implies a greater formation of so-called egg box structures. These differences resulted in their different rheological behaviour, as sodium alginate aqueous solutions exhibited a greater viscosity ( η at 1 s−1 = 3.8 ± 0.052 Pa·s) than commercial alginate (2.8 ± 0.024 Pa·s), which is related to the egg box structure developed. When gelled in the presence of calcium, an increase in the value of the elastic modulus was observed. However, the value of the tan δ for the extracted alginate was lower than that of commercial alginate gels, confirming a structure more densely packed, which implies a different restructuring of the alginate chain when gelling. These results confirm the suitability of using invasive Rugulopteryx okamurae as a source of calcium alginate gels. In this way, sustainable bio-based materials may be produced from undesired biomass that currently poses a threat to the ecosystem. [ABSTRACT FROM AUTHOR]

Maize starch, polyvinyl alcohol, glucose, and magnesium stearate are used as tablet excipients, acetylsalicylic acid as probe, polyvinyl acetate, and calcium alginate as protective membranes. By changing the proportions of the excipients, the nature and the thickness of the protective membrane, it was possible to optimize the formulation of a controlled release tablet. The mechanism and the kinetics of release of the active ingredient are evaluated using kinetic models: zero order, Higuchi, first order, Hixson–Crowell and Krosmeyer–Peppas. The representation of the released quantities using Krosmeyer–Peppas seems to be the most appropriate to describe the release mechanism (R2 ~ 1). The k and n values, Krosmeyer–Peppas, indicate that drug release is complex. The release rate of the AI is controlled by the erosion of the membrane and the relaxation of the chains of polymers constituting it. The solubility parameters (δ), according to Hansen, of the hydroxylated ingredients, predict compatibility and stability. [ABSTRACT FROM AUTHOR]

Calcium alginate fiber has become an ideal raw material for wound dressing preparation due to its excellent moisture absorption and biological compatibility. There are still some problems such as bacterial contamination of wounds and difficult observation of wound healing in the actual use process. To avoid bacterial contamination of the wound and visually observe the wound healing situation, a calcium alginate fiber with pH‐responsive and antibacterial properties has been developed by the facile and eco‐friendly one‐step method. In order to make the calcium alginate fiber can be used intelligently to continuously monitor wound changeable pH, the fiber is originally solution dyed by alizarin dye. And the antibacterial property of this calcium alginate fiber is mainly from silver nanoparticles (AgNPs) which are in situ reduced by alginate in the spinning solution. This one‐step wet spinning method can avoid the subsequent complicated process required for calcium alginate fiber functionalization while ensuring the material properties. Owing to the existence of AgNPs, the calcium alginate fiber prepared has a significant antibacterial effect on two kinds of gram bacteria. Therefore, this calcium alginate fiber exhibits good pH‐responsive and antibacterial properties performance and is an improvement upon the current flexible pH sensor to indicate wound healing. [ABSTRACT FROM AUTHOR]

A significant part of research in environmentally friendly agroindustrial production is aimed at immobilized bacterial preparations with retained capacity for active growth without loss of metabolic activity both during immobilization and after long-term storage and biotechnological use. In the present work, immobilization of members of the genus Azospirillum on natural and synthetic carriers was investigated. Efficiency of immobilization of the cells of A. brasilense strain SR80 in alginate hydrogel and vermiculite was investigated. Proliferative and metabolic activities of immobilized preparations were investigated. The prospects of using vermiculite and calcium alginate as matrices for Azospirillum immobilization are shown. [ABSTRACT FROM AUTHOR]

In this research, the vorinostat‐loaded alginate microparticles were created and their characterization was performed using scanning electron microscopy (SEM), energy‐dispersive X‐ray mapping (EDX‐mapping), and transmission electron microscopy (TEM). Differential scanning calorimetry (DSC) was used to assess the drug state and thermal behavior of vorinostat within the microparticles. The encapsulation efficiency and loading efficiency were determined, and the solubility of vorinostat in the microparticles was investigated. In vitro drug release studies demonstrated sustained release of vorinostat from the microparticles. The cytotoxicity of vorinostat‐loaded alginate microparticles was evaluated using HepG2, MCF‐7, and SK‐LU‐1 cell lines. The results indicated significant inhibition of cell growth, and the IC50 values were estimated. Overall, this study successfully demonstrated the fabrication of vorinostat‐loaded alginate microparticles using a microfluidic approach, suggesting a simple and effective delivery system for vorinostat with improved physicochemical and pharmacological properties. [ABSTRACT FROM AUTHOR]

In this article, the effectiveness of two different application methods (photocatalytic degradation and adsorption) onto the created solid nanomaterials for the removal of malachite green (MG) was investigated. Copper ferrite nanoparticles (CF) and copper ferrite/calcium alginate composite (CG) were synthesized as two studied solid samples. By using XRD, TGA, FTIR, DRS, nitrogen adsorption/desorption isotherm, pHPZC, SEM, and TEM, the physicochemical and morphological properties of the solid samples were tested. Sample dose, pH, initial MG concentration, shaking time, ionic strength, UV light power, and temperature were the key experimental parameters that were established. The obtained results demonstrated that at 40 °C, CG reached a greater adsorption capacity (297.62 mg/g). The spontaneous, endothermic, and advantageous adsorption process of MG was proved by the best fitting of pseudo-second order, Elovich, intra-particle diffusion, Langmuir, Dubinin-Radushkevich, and Temkin models onto all the produced materials. The maximum percentage of MG degradation by CG (89.9%) was accomplished by utilizing 1.0 g/L of catalyst mass, an initial MG concentration of 10 mg/L, and 33 W. Arrhenius and Eyring–Polanyi models well applied the MG photodegradation onto the catalyst surface. [ABSTRACT FROM AUTHOR]

The widespread use of highly complex synthetic dyes like reactive dyes in the textile industry has some adverse environmental impacts and deserves close attention. Biological treatment of these effluents utilizing various species of bacteria with remarkable efficiency in dye removal is still considered promising. Our current study deals with immobilizing an isolated bacterial strain into calcium alginate (Ca/Alg) gel beads and using it to treat pernicious pollutants like synthetic dyes. A potential Reactive Blue 19 (RB19)‐degrading Enterobacter cloacae strain A1 was isolated from the Kashan textile industry and was characterized by 16S rDNA gene sequencing. The decolorization ability of strain A1 was assessed by time‐based studies using free bacterial cells/immobilized in Ca/Alg. Based on the results of the 16S rDNA gene sequencing, it appears that strain A1 belonged to E. cloacae, with a 99.74% similarity. The findings suggest that immobilized strain A1 accomplished maximum decolorization activity compared with the free cells. The immobilized strain could utterly decompose and decolorize 0.05 mg/mL of RB19 within 48 h, while the free bacterial strain decolorized RB19 within 5 days. Moreover, Ca/Alg gel beads can maintain their efficiency for over three decolorization cycles. Further infrared spectroscopy (FTIR) and gas chromatograph mass spectrometer (GC/MS) investigation declared complete RB19 decomposition on reaction products. Artemia salina was used to investigate the toxicity of dye and its degraded metabolites. The LC50 values signified the pure dye as very toxic with 0.01 mg/mL concentration, while after‐treatment products showed no toxic effect on larvae. This immobilization technique increased the applicability of bacterial strain for dye removal. It was beneficial for the decolorization of RB19 from textile wastewater due to a remarkable reduction in time. Notably, strain A1‐immobilized beads can maintain their activity for three consecutive decolorization cycles without a considerable decrease in efficiency. Practitioner Points: The remarkable capacity of immobilized Enterobacter cloacae strain A1 for Reactive Blue 19 (RB19) removalImmobilized A1 strain showed two‐fold higher removal than free one over 48 hA promising method for enhancing RB19 decolorizationDecolorization was due to degradation based on UV–Vis, FTIR, and GC/MS analysisNon‐toxic posttreatment products for Artemia [ABSTRACT FROM AUTHOR]

Magnetic composite adsorbents using iron oxide nanoparticles have been produced in the past for glyphosate removal; however, the effect of the magnetic iron oxide content in the chitosan/calcium alginate hydrogel matrix on glyphosate removal efficiency has not been investigated. In this study, magnetic chitosan/calcium alginate hydrogel (MCAH) beads were synthesized according to our previous study with the same methodology with a magnetic iron oxide nanoparticle (MIONP) content of 33%, 50%, and 60% (w/w). Iron content was analyzed by characterization study. The increasing iron weight percentage was detected at the magnetic beads with the FESEM-EDX analysis. The magnetism of the MCAH beads increased with the higher MIONP content according to VSM analysis. The surface area and porosity of MCAH beads decreased with MIONP content increase according to the BET analysis. The results showed that the higher MIONP content increases the reaction rate by 13 percent but does not change the resultant removal efficiency significantly. [ABSTRACT FROM AUTHOR]

The acetylcholinesterase (AChE) is involved in termination of synaptic transmission at cholinergic synapses and plays a vital role in the insecticide detection and inhibitor screening. Here, we report the heterologous expression of an AChE from Tetronarce californica (TcA) in Escherichia coli (E. coli) as a soluble active protein. TcA was immobilized in calcium alginate beads; the morphology, biochemical properties, and insecticide detection performance of free and immobilized TcA were characterized. Moreover, we used sequence, structure-based approaches, and molecular docking to investigate structural and functional characterization of TcA. The results showed that TcA exhibited a specific activity of 102 U/mg, with optimal activity at pH 8.0 and 30 °C. Immobilized TcA demonstrated superior thermal stability, pH stability, and storage stability compared to the free enzyme. The highest sensitivity of free TcA was observed with trichlorfon, whereas immobilized TcA showed reduced IC50 values towards tested insecticides by 3 to 180-fold. Molecular docking analysis revealed the interaction of trichlorfon, acephate, isoprocarb, λ-cyhalothrin, and fenpropathrin in the active site gorge of TcA, particularly mediated through the formation of hydrogen bonds and π-π stacking. Therefore, TcA expressed heterologously in E. coli is a promising candidate for applications in food safety and environmental analysis. Key points: • T. californica AChE was expressed solubly in prokaryotic system. • The biochemical properties of free/immobilized enzyme were characterized. • The sensitivity of enzyme to insecticides was evaluated in vitro and in silico. [ABSTRACT FROM AUTHOR]

Nanoparticles of Al2O3, ZrO2, Fe3O4 and their mixed oxides are synthesized adopting new green methods. Aloe-vera gel is identified as a capping agent for controlling the size of particles. The slow generation of precipitating agent, NH3, and increase in viscosity of medium, assist the synthesis. The mixed nanoparticles are found to be very effective in the simultaneous extraction of phosphate (qe:112.14 mg/g) and chromate (qe:122.6 mg/g) from water atpH: 4, equilibration time: 60 min and dosage: 0.12 g/150 mL. These particles when doped in calcium alginate beads to make the filtration easy, the effective pH is increased to 10 for the simultaneous removal of both the pollutants with enhancement in adsorption capacities for phosphate (qe:130.01 mg/g) and chromate(qe:144.12 mg/g) at the equilibration time: 90 min and dosage: 0.10 g/150 mL. The nano mixed oxide as well as beads are characterized by FTIR, XRD, FESEM and EDX techniques. Spontaneous and endothermic nature of sorption is revealed by thermodynamic investigations. The adsorbents are robust and effective up to six regeneration cycles. The experimental data are best fitted with the Langmuir isotherm and pseudo-second-order kinetic models with R2 values > 0.99 for both the adsorbates. The methodology developed is applied to water remediation for phosphate and chromate. The importance of the present investigation is that the adsorbents based on nanomaterials synthesised by new green methods are identified to have high adsorption capacities for the simultaneous extraction of chromate and phosphate from polluted water. [ABSTRACT FROM AUTHOR]

Simple Summary: Artificial diets are one of the most critical components in insect mass-rearing facilities worldwide. Research on artificial diets to rear pestiferous tephritid flies dates back to the 1950s but is still a topic of great relevance, as fruit flies represent one of the ten most important pests of fruit in temperate and tropical regions of the world. In the past 15 years, much research has been performed to develop liquid- or gel-based diets more closely resembling the rearing environment a wild fruit fly larva experiences inside a fruit in nature. To identify new gelling agents that could perform better than already established ones such as agar and carrageenan, we assessed the performance of calcium alginate, a gelling agent widely used in the food industry, that had not been tested in the case of fruit fly mass rearing. We also examined larval density in gel diets as a critical factor that affects insect-rearing systems. Our results show that agar and carrageenan diets outperformed calcium alginate diets broadly and that the effects of larval density depended on the gel type used. We believe that the applications of calcium alginate in tephritid rearing should be analyzed in more depth in future studies. Research on larval rearing and nutrition of tephritid flies on artificial diets is key for the sterile insect technique. Here, we examined the effects of the type of gel (calcium alginate, agar, or carrageenan), at varying percentages in artificial diets for the polyphagous pest Anastrepha ludens, on the physicochemical and nutritional traits of the diets, and the effects of the type of gel, the gel content and the larval density (larvae/g of diet) used in production, quality parameters for mass-reared tephritids, diet removal (an indirect estimation of diet consumption), and nutritional traits of flies. Regardless of the gel content, calcium alginate diets were firmer and more resistant to penetration than the agar and carrageenan diets. The larval recovery, pupation, pupal weight, and flight ability of A. ludens were lower in calcium alginate diets than in agar and carrageenan diets. Diet removal was higher in calcium alginate diets; however, low levels of ammonium and high levels of uric acid in excretions from larvae on these diets suggest an alteration in protein metabolism. The firmness and penetration resistance characteristics of calcium alginate diets may have limited movement and feeding of larvae, but this could be overcome by the collective feeding of large groups of larvae. Our findings provide insights into the mechanism governing gel-diet rearing systems for A. ludens. [ABSTRACT FROM AUTHOR]

In this paper, the photocatalysis material CA+, which uses calcium alginate as carrier and cetyltrimethylammonium bromide as surfactant, was studied. The morphology and structure of the prepared CA+ were characterised by SEM, TEM, FT-IR and Raman spectroscopy. The surface electrical properties and stability of the catalytic materials were evaluated by Zeta potential and cycling performance measurements, and the data were analyzed and processed according to the principle of degradation kinetics. The results show that Ag@AgCl Nanoparticles are distributed on the cross-linked structure of CA in the form of clusters. The prepared CA+ photocatalyst material has good adsorption performance and photocatalytic activity for tetracycline (TC). Temperature has a significant effect on the degradation of TC by photocatalytic materials. The photocatalytic degradation rate is the highest at 40 °C, and the photocatalytic reaction rate was 0.08276 min−1. The photocatalytic degradation process at different temperatures conforms to the quasi first-order reaction kinetics. Adding a certain amount of H2O2 can produce more active species O2−. The photocatalytic material has the advantages of good stability, short photocatalytic degradation time, high catalytic efficiency, and can be used for the degradation of actual tetracycline polluted wastewater. [ABSTRACT FROM AUTHOR]

Intrauterine adhesions (IUA) has become one of the main causes of female infertility. How to effectively prevent postoperative re-adhesion has become a clinical challenge. In this study, a mussel-inspired dual-network hydrogel was proposed for the postoperative anti-adhesion of IUA. First, a calcium alginate/polyacrylamide (CA-PAM) hydrogel was prepared via covalent and Ca2+ cross-linking. Benefiting from abundant phenolic hydroxyl groups, polydopamine (PDA) was introduced to further enhance the adhesion ability and biocompatibility. This CA-PAM hydrogel immersed in 10 mg/mL dopamine solution possessed remarkable mechanical strength (elastic modulus > 5 kPa) and super stretchability (with a breaking elongation of 720%). At the same time, it showed excellent adhesion (more than 6 kPa). Surprisingly, the coagulation index of the hydrogel was 27.27 ± 4.91, demonstrating attractive coagulation performance in vitro and the potential for rapid hemostasis after surgery. [ABSTRACT FROM AUTHOR]

Nowadays, public concern is focused on the degradation of water quality. For this reason, the development of innovative technologies for water treatment in view of (micro)pollutant removal is important. Indeed, organic (micro)pollutants, such as pharmaceuticals, herbicides, pesticides and plasticizers at concentration levels of μg L−1 or even ng L−1 are hardly removed during conventional wastewater treatment. In view of this, thermo-plasma expanded graphite, a light-weight innovative material in the form of a powder, was encapsulated into calcium alginate to obtain a granular form useful as filtration and adsorption material for removal of different pollutants. The produced material was used to remove atrazine, bisphenol-A, 17-α-ethinylestradiol and carbamazepine (at concentration levels of 125, 250 and 500 µg L−1) by top-down filtration. The effect of flow rate, bed depth and adsorbent composition was evaluated based on breakthrough curves. The experimental data was analysed with the Adams-Bohart model in view of scale-up. Under optimal conditions, removal and adsorption capacity of respectively about 21%, 21%, 38%,42%, 43 µg g−1, 44 µg g−1, 37 µg g−1 and 87 µg g−1 were obtained for atrazine, bisphenol, 17-α ethinylestradiol and carbamazepine when using 0.12 g of thermo-plasma expanded graphite to treat 200 mL at 500 µg L−1 (for each compound) of solution obtaining at contact time of 20 min. The granular form of TPEG obtained (GTPEG) by entrapping in calcium alginate results to have a good adsorbent property for the removal of carbamazepine, atrazine, bisphenol A and 17-α ethinylestradiol from water at concentration levels between 250 and 500 μg L−1. Promising results confirm the adsorbent properties of TPEG and push-up us to investigate on its application and improve of its performance by evaluating different entrapping materials. [ABSTRACT FROM AUTHOR]

Solar-driven interfacial evaporation is increasingly used in desalination due to its excellent evaporation performance. The continuous evaporation of water would lead to an increase in the salinity of the evaporator, which has been often neglected and rarely exploited. In this work, a calcium alginate hydrogel and nickel foam composited membrane (CHN) was proposed as a new platform for constructing solar-powered hybrid systems with the function of synchronous desalination and salinity power generation. The calcium alginate hydrogels can reduce the enthalpy of water evaporation and convert the salinity gradient between the evaporator and seawater into electrical energy. The evaporation rate of the mixed system (CHN-CB) with carbon black (CB) as the solar absorber is greater than 2.1 kg m−2 h−1. Additionally, under 1 sun, the system achieved a maximum short-circuit current of 20.3 mA m−2 and generated an extra electrical power of 5.3 mW m−2. As a universal multi-energy conversion platform, the CHN membranes can combine different photothermal materials for synchronous evaporation and salinity gradient power generation. These results open new paths for the combination of desalination and power generation, demonstrating the potential for diversified use of blue energy. [ABSTRACT FROM AUTHOR]

Control of plant virus diseases largely depends on the induced plant defence achieved by the external application of synthetic chemical inducers with the ability to modify defence‐signalling pathways. However, most of the molecular mechanisms underlying these chemical inducers remain unknown. Here, we developed a chitosan‐coated lentinan‐loaded hydrogel and discovered how it protects plants from different virus infections. The hydrogel was synthesized by coating chitosan on the surface of the calcium alginate‐lentinan (LNT) hydrogel (SL‐gel) to form a CSL‐gel. CSL‐gels exhibit the capacity to prolong the stable release of lentinan and promote Ca2+ release. Application of CSL‐gels on the root of plants induces broad‐spectrum resistance against plant viruses (TMV, TRV, PVX and TuMV). RNA‐seq analysis identified that Nicotiana benthamiana calmodulin‐like protein gene 3 (NbCML3) is upregulated by the sustained release of Ca2+ from the CSL‐gel, and silencing and overexpression of NbCML alter the susceptibility and resistance of tobacco to TMV. Our findings provide evidence that this novel and synthetic CSL‐gel strongly inhibits the infection of plant viruses by the sustainable release of LNT and Ca2+. This study uncovers a novel mode of action by which CSL‐gels trigger NbCML3 expression through the stable and sustained release of Ca2+. Summary statement: Synthesis of chemical inducers with the ability to induce plant defence or modify defence‐signalling pathways is a practical way to control plant virus diseases. However, the molecular mechanisms underlying the action of chemical inducers remain largely unknown. This study demonstrates that a chitosan‐coated lentinan‐loaded calcium alginate hydrogel with prolonged and sustained release of lentinan and Ca2+ in plant roots promotes plant growth and enhances broad‐spectrum virus resistance by inducing NbCML3 expression in N. benthamiana. [ABSTRACT FROM AUTHOR]

Two types of alginates, AlgLF and AlgP, were used in this study to produce alginate beads by electro-vibratory extrusion. AlgLF and AlgP exhibited different Mannuronate/Guluronate (M/G) ratios and molecular weights as measured by NMR and SEC-MALS. The calcium chloride concentration was found to have the greatest effect on bead size. Higher concentrations resulted in smaller beads. AlgLF with a higher molecular weight and a lower proportion of G blocks showed smaller beads. For both alginates, the bead size was also influenced by the flow rate and vibration frequency. Alginate solution aging showed a minimal effect. Alginate reticulation was modeled using a mathematical equation. The study provides insights for the optimization of alginate-based materials in different applications by shedding light on the main factors influencing bead size. The importance of the molecular weight, M/G ratio and calcium ion concentration in the gelling process is highlighted, providing opportunities for the tailoring of alginate materials through a phenomenological model. [ABSTRACT FROM AUTHOR]

Implant‐related infections (IRIs), characterized by the formation of bacterial biofilms and immunosuppressive microenvironment, are a common but tricky clinical issue. In this study, a self‐adaptive theranostics nanosystem is designed based on phase change material (PCM) for IRIs therapy, which can monitor the severity of infection in real time and automatically provide the most appropriate treatment on demand. The nanosystem called CaAlg/LOD/POD@MNO/FAs (CLPM) is made of the fatty acids (FAs) core with dissolved minocycline (MNO) and the calcium alginate (CaAlg) shell with an immobilized lactate oxidase/pyruvate oxidase (LOD/POD) enzyme‐linked system. When the level of infection is mild (wound temperature < 39 °C), the CLPMs perform a bacteriostatic function by slowly releasing MNO from the solid‐phase FAs core. When the infection deteriorates (wound temperature > 39 °C), the solid‐to‐liquid phase change of FAs not only enables a rapid release of MNO but also disrupts the mechanical strength of the biofilm skeleton doped with CLPM, performing a bactericidal function. In addition, CLPM can reduce the accumulation of bacteria‐derived lactate to address lactate‐induced immunosuppression and enhance immune memory response, thereby inhibiting infection recurrence. [ABSTRACT FROM AUTHOR]

Summary: Alginate‐based encapsulation is an effective probiotics delivery system in the intestine. However, due to calcium ions and gastric juice damaging cell wall/membrane integrity during freeze‐drying and gastrointestinal ingestion, lots of cell lose their viability. This study, taking Lactiplantibacillus plantarum grx16 as an example, indicated that co‐encapsulation of cryoprotectants and porous starch within calcium alginate capsules (CAC) could combinedly improve the viability of probiotics encapsulated. Compared with calcium alginate‐protectant capsule (CAC‐Pro) (50.67%), the combination of porous starch increased the encapsulation rate of PS0.8‐CAC‐Pro to 82.68%. Meanwhile, the death rate constants of PS0.8‐CAC‐Pro decreased by 31.3% (−20 °C), 13.5% (4 °C) and 7.5% (25 °C), respectively. The survival rate of PS0.8‐CAC‐Pro was 81.94% after continuous simulated gastrointestinal digestion, which was significantly higher than that of CACs (69.46%) and CAC‐Pro (76.92%). This study provided an effective approach for modifying alginate capsule to reduce the loss of probiotics viability. [ABSTRACT FROM AUTHOR]

Effects of different pH values (4–7) and whey protein isolate (WPI) concentrations (0.5–1.5%) were evaluated on physical, mechanical, and rheological properties of cold‐set alginate‐based soybean oil hybrid emulgels. The pH value changes were more effective than WPI concentration changes on emulgel properties. According to syneresis and texture profile analysis results, 1% WPI was selected as the optimum concentration. The XRD analysis showed that calcium alginate (CA) emulgel at pH 6 had a different peak at 2θ of 14.8°, likely indicating the highest amount of ion‐bridging and maximum number of junction zones. The homogeneity of CA and CA + WPI emulgels (determined by image entropy analysis) decreased by pH reduction from 7 to 4, which can be related to acid‐induced intermolecular interactions between alginate chains. The rheological properties of CA and CA + WPI emulgels revealed predominant elastic character (G′ > G′′) at different pH values. Creep test results showed that the relative recovery of emulgel prepared at pH 7 and 5 was 18.10 and 63.83%, respectively, suggesting pH reduction contributed to increase in the elastic component of material. The findings of this study can be applied for developing structured cold‐set emulgels as solid fat replacers in meat and dairy products. [ABSTRACT FROM AUTHOR]

Tannase from Aspergillus ficuum was immobilized by two different techniques for comparison of kinetic and thermodynamic parameters. Tannase was either entrapped in calcium alginate beads or covalently-immobilized onto magnetic diatomaceous earth nanoparticles. When immobilized on nanoparticles, tannase exhibited lower activation energy (15.1 kJ/mol) than when immobilized in alginate beads (31.3 kJ/mol). Surprisingly, the thermal treatment had a positive effect on tannase entrapped in alginate beads since the enzyme became more solvent exposed due to matrix leaching. Accordingly, the proposed mathematical model revealed a two-step inactivation process. In the former step the activity increased leading to activation energies of additional activity of 3.1 and 26.8 kJ/mol at 20–50 °C and 50–70 °C, respectively, while a slight decay occurred in the latter, resulting in the following thermodynamic parameters of denaturation: 14.3 kJ/mol activation energy as well as 5.6–9.7 kJ/mol standard Gibbs free energy, 15.6 kJ/mol standard enthalpy and 18.3–29.0 J/(K·mol) standard entropy variations. Conversely, tannase immobilized on nanoparticles displayed a typical linear decay trend with 43.8 kJ/mol activation energy, 99.2–103.1 kJ/mol Gibbs free energy, 41.1–41.3 kJ/mol enthalpy and −191.6/−191.0 J/(K·mol) entropy of denaturation. A 90-day shelf-life investigation revealed that tannase immobilized on nanoparticles was approximately twice more stable than the one immobilized in calcium alginate beads, which suggests its use and recycling in food industry clarification operations. To the best of our knowledge, this is the first comparative study on kinetic and thermodynamic parameters of a tannase produced by A. ficuum in its free and immobilized forms. [ABSTRACT FROM AUTHOR]

Polyurea-crosslinked calcium alginate (X-Ca-Alg) aerogels were investigated under physiological relevant conditions and showed signs of degradation. Geometric and spectral measurements were made to quantify this degradation in vitro and ex vivo. The time dependence in vitro degradation of these aerogels was accelerated in the presence of shear force. Diagnostic ultrasound techniques have been shown to reliably identify X-Ca-Alg aerogels both in vitro and ex vivo as well as detect degradation of these aerogels in these different environments. Geometric measurements of aerogel implants taken from the US images closely match the measurements taken from optical imaging showing the reliability of US imaging and degradation tracking of implants in clinical settings. Acoustic attenuation was also calculated and was shown to indicate and identify aerogel degradation. [ABSTRACT FROM AUTHOR]

[Display omitted] Transcatheter arterial embolization (TAE) has played a huge role in the interventional treatment of organ bleeding and accidental bleeding. Choosing bio-embolization materials with good biocompatibility is an important part of TAE. In this work, we prepared a calcium alginate embolic microsphere using high-voltage electrostatic droplet technology. The microsphere simultaneously encapsulated silver sulfide quantum dots (Ag 2 S QDs) and barium sulfate (BaSO 4), and fixed thrombin on its surface. Thrombin can achieve an embolic effect while stopping bleeding. The embolic microsphere has good near-infrared two-zone (NIR-II) imaging and X-ray imaging effects, and the luminous effect of NIR-II is better than that of X-rays. This breaks the limitations of traditional embolic microspheres that only have X-ray imaging. And the microspheres have good biocompatibility and blood compatibility. Preliminary application results show that the microspheres can achieve a good embolization effect in the ear arteries of New Zealand white rabbits, and can be used as an effective material for arterial embolization and hemostasis. This work realizes the clinical embolization application of NIR-II combined with X-ray multimodal imaging technology in biomedical imaging, achieving complementary advantages and excellent results, more suitable for studying biological changes and clinical applications. [ABSTRACT FROM AUTHOR]

In the present study, Aspergillus uvarum was subjected to random mutagenesis, by treatment with chemical mutagen i.e., Ethyl methanesulfonate (EMS). Among the various mutant strains of A. uvarum, the strain that was obtained after treatment with EMS at 12% v/v concentration and 60 min of exposure time showed 1.8-fold and 1.4-fold increased cellulase activity using submerged (SmF) and solid state fermentation (SSF), respectively, as compared to the parent wild strain. Partial purification of the cellulase by ammonium sulphate fractionation and dialysis showed 1.46 and 2.02 fold purification, respectively. Among the several concentrations of sodium alginate and calcium chloride used for immobilization, partially purified cellulase demonstrated maximum activity with 2% w/v concentration of sodium alginate and 0.2 M concentration of calcium chloride. The optimal temperature and pH for immobilized cellulase were observed to be 60 °C and 7, respectively. Furthermore, the immobilized enzyme presented increased reusability, having 18.5% relative activity after five consecutive uses, and was more stable, maintaining 64.5 and 48.7% of its initial activity at 4 and 30 °C, respectively, after 30 days of storage. [ABSTRACT FROM AUTHOR]

For much of the Caribbean region, plastic pollution and the persistence of the great Atlantic Sargassum belt lead to significant regional loss in biodiversity, employment and tourism. Yet, seaweeds such as Sargassum possess all the characteristics for bioplastic production. This study presents a new process on the production of biodegradable calcium alginate (Ca(Alg)2) composite bioplastic, and evaluates its economic feasibility and environmental impact in the Caribbean, compared to bio-based polylactic acid (PLA) and synthetic plastics (PET). Our cradle-to-gate life cycle impact assessment (LCIA) shows normalized (kg CO2eq per kg plastic) greenhouse gas (GHG) impacts 3 to 7 times higher for the baseline alginate composite process over those of PLA and PET films – linked mainly to chemical consumption. However, through the integration of abundant bioenergy from the local paper industry and the nascent E-methanol (E-MeOH) supply chains, GHG impact reduces by 79% – illustrating a pathway to a sustainable bioplastic production flowsheet. More attractively, the alginate bioplastic outperforms in providing ultra-low oxygen barrier packaging properties – with a required mass of plastic material producing a total carbon footprint (kg CO2eq) 64–978 times lower than PLA and PET respectively, and overall packaging costs 280 times less than current synthetic plastic. Techno-economics illustrate that a total annualized cost (TAC) for alginate bioplastic of $US 4.56 per kg is possible, ensuring high economic feasibility, comparable to current commercial bio-based alternatives. Moreover, sensitivity analysis highlights that variability in TAC was mainly associated with sodium alginate utilization in the manufacture process – contributing up to 67% to the overall cost. In light of this, the integration of sound policies aligned to improved consumer awareness and reduced plastic waste can help to drive greater economic feasibility of the alginate bioplastic industry. Ultimately, our study illustrates a viable and sustainable alginate bioplastic alternative, promoting and informing on packaging innovation while achieving low carbon operations within the Caribbean plastic sector. [ABSTRACT FROM AUTHOR]

[Display omitted] Underwater superoleophobic coatings exhibit promising prospects in the field of oil contamination resistance. However, their poor durability, stemming from the fragile structures and unstable hydrophilicity, greatly restricted their development. In this report, we proposed a novel strategy of combination water-induced phase separation and biomineralization to prepare the robust underwater superoleophobic epoxy resin-calcium alginate (EP-CA) coating by utilizing a surfactant-free emulsion of epoxy resin/sodium alginate (EP/SA). The EP-CA coating not only exhibited excellent adhesion to various substrates, but also had remarkable resistance to the physical/chemical attacks such as abrasion, acid, alkali and salt. It could also protect the substrate (e.g., PET substrate) from the damage of organic solution and the fouling of crude oil. This report provides a new perspective to fabricate robust superhydrophilic coating with a facile way. [ABSTRACT FROM AUTHOR]

Simple Summary: The immune system plays an important role in the skeletal system during bone repair and regeneration, especially in the oral environment with its constant host–microbe interactions. This study aims to determine the effect of the controlled delivery of immunomodulatory biologicals on alveolar bone regeneration. This study aims to explore the regulatory effect of a hydrogel microbead, coated with multiple immunomodulatory substances (cytosine-phosphate-guanosine oligodeoxynucleotides and glucosylxanthone Mangiferin), on alveolar bone regeneration. The results showed that the complex microbeads could promote the anti-inflammatory response in splenocytes, inhibit RANKL-mediated osteoclastogenesis in a co-culture model of activated splenocytes and osteoclast precursors cells, and promote new bone deposition in mice. This study demonstrated that alveolar bone regeneration could be regulated by cytosine-phosphate-guanosine oligodeoxynucleotides and glucosylxanthone Mangiferin, which provides a potential therapeutic strategy for the treatment of alveolar bone regeneration. The immune system plays an important role in the skeletal system during bone repair and regeneration. The controlled release of biological factors from the immune system could facilitate and optimize the bone remodeling process through the regulation of the activities of bone cells. This study aimed to determine the effect of the controlled delivery of immunomodulatory biologicals on bone regeneration. Immunostimulatory cytosine-phosphate-guanosine oligodeoxynucleotides (CpG ODN) and glucosylxanthone Mangiferin (MAG)-embedded microbeads were incubated with P. gingivalis-challenged splenocytes, or co-cultured with RAW264.7 cells. The effect of CpG ODN/MAG-containing microbeads on bone regeneration was then tested in vivo in a mouse alveolar bone defect model. The results demonstrated that MAG significantly antagonized P. gingivalis proliferation and reduced the live/dead cell ratio. After the addition of CpG ODN + MAG microbeads, anti-inflammatory cytokines IL-10 and IL-4 were upregulated on day 2 but not day 4, whereas pro-inflammatory cytokine IL-1β responses showed no difference at both timepoints. RANKL production by splenocytes and TRAP+ cell formation of RAW264.7 cells were inhibited by the addition of CpG ODN + MAG microbeads. Alveolar bony defects, filled with CpG ODN + MAG microbeads, showed significantly increased new bone after 4 weeks. In summary, this study evaluated a new hydrogel-based regimen for the local delivery and controlled release of biologicals to repair and regenerate alveolar bony defects. The combined CpG ODN + MAG treatment may promote alveolar bone regeneration through the anti-microbial/anti-inflammatory effects and the inhibition of RANKL-mediated osteoclastogenesis. [ABSTRACT FROM AUTHOR]

In this study, a simple spectrophotometric method has been applied to investigate the adsorption of Hg(II) from aqueous solution on glycine functionalised magnetic nanoparticles entrapped calcium alginate beads (GFMNPECABs) from aqueous solution. The adsorbent was characterised by Fourier Transform Infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Brunauer-Emmett-Teller (BET) analysis. The influence of pH, contact time, temperature, adsorbent dose etc. were studied and optimised. The results of batch adsorption experiment showed that maximum adsorption capacity of 3.59 mg g‒1 was obtained at pH 5 and 65 minutes of contact time.The adsorption behaviour of Hg(II) was evaluated using Langmuir, Freundlich and Temkin isotherm and it was found that the data best fitted with the Freundlich model. The kinetic study revealed that the adsorption follows pseudo-second-order kinetics with a high correlation coefficient of R2 = 0.9998. The thermodynamic investigation verified the endothermic and spontaneous nature of the adsorption process with an enthalpy change (∆H) and entropy change (∆S) of 20.25 kJ mol−1 and 79.88 J mol‒1 K, respectively. The adsorption studies were monitored based on the reaction of Hg(II) with iodine and leucocrystal violet. This study shows that GFMNPECABs is a promising adsorbent for removal of Hg(II) from aqueous solution and the above spectrophotometric method could be satisfactorily applied for adsorption studies. [ABSTRACT FROM AUTHOR]

In response to the shortcomings of traditional concrete crack repair materials, a new generation of repair materials was developed – a microbial repair material (MRM) based on sodium alginate modification. A brushing technique is used to fix microorganisms on the cracks to be repaired so that they can deposit calcium carbonate (CaCO3) in situ to repair the cracks. The fundamental properties of the MRM were studied, along with the macroscopic morphology and surface water absorption of specimens before and after the repair of mortar cracks. The material changes and microstructure of the repair products were also analysed. The results showed that the calcium carbonate content, water absorption ratio and heating shrinkage rate of the MRM with modified sodium alginate were better than those of the repair material without microorganisms. It was also found that the microorganisms were fixed in cracks on the surface of the mortar using the brushing technique with sodium alginate as the carrier. They adhered tightly to the cracks after only two repairs and produced repair products (mainly calcium alginate and calcium carbonate) and the surface water absorption ratio was reduced by about 65% compared with that before repair. [ABSTRACT FROM AUTHOR]

Despite an emerging catalogue of collective behaviours in communities of homogeneously distributed cell‐like objects, microscale protocell colonies with spatially segregated populations have received minimal attention. Here, we use microfluidics to fabricate Janus‐like calcium alginate hydrogel microspheres with spatially partitioned populations of enzyme‐containing inorganic colloidosomes and investigate their potential as integrated platforms for domain‐mediated chemical communication and programmable protocell‐matrix dynamics. Diffusive chemical signalling within the segregated communities gives rise to increased initial enzyme kinetics compared with a homogeneous distribution of protocells. We employ competing enzyme‐mediated hydrogel crosslinking and decrosslinking reactions in different domains of the partitioned colonies to undertake selective expulsion of a specific protocell population from the community. Our results offer new possibilities for the design and construction of spatially organized cytomimetic consortia capable of endogenous chemical processing and protocell‐environment interactivity. [ABSTRACT FROM AUTHOR]

Despite an emerging catalogue of collective behaviours in communities of homogeneously distributed cell‐like objects, microscale protocell colonies with spatially segregated populations have received minimal attention. Here, we use microfluidics to fabricate Janus‐like calcium alginate hydrogel microspheres with spatially partitioned populations of enzyme‐containing inorganic colloidosomes and investigate their potential as integrated platforms for domain‐mediated chemical communication and programmable protocell‐matrix dynamics. Diffusive chemical signalling within the segregated communities gives rise to increased initial enzyme kinetics compared with a homogeneous distribution of protocells. We employ competing enzyme‐mediated hydrogel crosslinking and decrosslinking reactions in different domains of the partitioned colonies to undertake selective expulsion of a specific protocell population from the community. Our results offer new possibilities for the design and construction of spatially organized cytomimetic consortia capable of endogenous chemical processing and protocell‐environment interactivity. [ABSTRACT FROM AUTHOR]

Recently calcium alginate has been successfully applied to encapsulate asphalt rejuvenator, which can protect asphalt rejuvenator from early leakage and release asphalt rejuvenator when triggered by specific factors such as cracks. The interfacial adhesion property of asphalt binder with calcium alginate carrier is of great importance to its actual performance. In this paper, the molecular model of the interface region between asphalt binder and calcium alginate was established, and molecular dynamics simulations were performed on it to investigate the molecular interaction at the interface region. By extracting and processing the data during the simulation process, the interfacial adhesion behavior was expounded using the spreading coefficient (S), permeation depth and permeation degree. Furthermore, the interfacial adhesion strength was evaluated by adopting the interfacial adhesion work. Results showed that the value of S was greater than 0, implying that asphalt binder could wet the surface of calcium alginate. Saturate had the highest value of permeation degree, followed by resin, aromatic and asphaltene. However, asphalt binder could not infiltrate into the interior of TiO2, only accumulating and spreading on the surface of TiO2. The interfacial adhesion work of unaged and aged asphalt binder to calcium alginate was −114.18 mJ/m2 and −186.37 mJ/m2, respectively, similar to that of asphalt–aggregate interface. The van der Waals interactions contributed the most to the formation of the interfacial adhesion strength. In addition, a certain degree aging of asphalt binder and addition of titanium dioxide in the calcium alginate carrier were helpful to enhance the interfacial adhesion strength. [ABSTRACT FROM AUTHOR]

The survival of probiotics in food products face various challenges during the production process. One of the emerging processes in the production of food products is 3D printing.The effect of this process on the viability of probiotics has not been studied so far.In this research, the effect of micro - encapsulation on cell viability during the process of 3D printing and cookie baking (based on waste from confectionery products) was investigated. First, the conditions for the production of micro -capsules were optimized by modulating the percentage of sodium alginate and calcium chloride solutions. Then, the effect of micro - encapsulation with different concentrations of micro -capsules (10, 5, 0% w/w) on the firmness of the dough texture was also investigated as an important factor in the printability of the dough. Finally, the cell viability was evaluated during the printing and baking process (150°C and 180°C for 10 minutes).The results of the microscopic images showed that with the increase in the concentration of sodium alginate and calcium chloride solution, the uniformity and sphericity of the micro -capsule increases. The efficiency of alginate -based micro -encapsulation in this method was 89.41%. The optimal concentration of micro -capsules in order to have the desired printability of baked dough, was reported as 5% w/w. Microencapsulation increased the survival rate of probiotics during 3D printing and baking. The survival percentage of microencapsulated probiotics (T2) after 3D printing and baking (150°C temperature) was 96.86% and 62.58%, respectively. Meanwhile, the survival percentage for the sample containing free cells (T1) was reported 60.77% and 43.05%, respectively. However, no viable probiotic cells were observed in both free and encapsulated cells conditions at 180°C. [ABSTRACT FROM AUTHOR]

In this research work the thorium uptake on immobilized protonated orange peel was studied in a batch system. The effects of effective parameters such as biosorbent dosage, initial metal ion concentration, and contact time on the biosorption of thorium were analyzed. The biosorption capacity of the immobilized orange peel for thorium at optimal conditions of initial pH 3.8, biosorbent dosage 8 g/L, and initial thorium concentration 170 mg/L was found to be 18.65 mg/g. According to the results of contact time, the biosorption process reached equilibrium after around 10 h of contact. Investigation of the kinetics showed that the biosorption of thorium onto immobilized orange peel follows the pseudo-second-order model. The Langmuir and Freundlich isotherms were used to model the experimental equilibrium data. The results showed better agreement by the Langmuir isotherm. The maximum absorption capacity of immobilized protonated orange peel for thorium adsorption was predicted by the Langmuir isotherm at 29.58 mg/g. [ABSTRACT FROM AUTHOR]

Background: Aromatic α-hydroxy ketones, such as S-2-hydroxypropiophenone (2-HPP), are highly valuable chiral building blocks useful for the synthesis of various pharmaceuticals and natural products. In the present study, enantioselective synthesis of 2-HPP was investigated by free and immobilized whole cells of Pseudomonas putida ATCC 12633 starting from readily-available aldehyde substrates. Whole resting cells of P. putida, previously grown in a culture medium containing ammonium mandelate, are a source of native benzoylformate decarboxylase (BFD) activity. BFD produced by induced P. putida resting cells is a highly active biocatalyst without any further treatment in comparison with partially purified enzyme preparations. These cells can convert benzaldehyde and acetaldehyde into the acyloin compound 2-HPP by BFD-catalyzed enantioselective cross-coupling reaction. Results: The reaction was carried out in the presence of exogenous benzaldehyde (20 mM) and acetaldehyde (600 mM) as substrates in 6 mL of 200 mM phosphate buffer (pH 7) for 3 h. The optimal biomass concentration was assessed to be 0.006 g dry cell weight (DCW) mL− 1. 2-HPP titer, yield and productivity using the free cells were 1.2 g L− 1, 0.56 g 2-HPP/g benzaldehyde (0.4 mol 2-HPP/mol benzaldehyde), 0.067 g 2-HPP g− 1 DCW h− 1, respectively, under optimized biotransformation conditions (30 °C, 200 rpm). Calcium alginate (CA)–polyvinyl alcohol (PVA)-boric acid (BA)-beads were used for cell entrapment. Encapsulated whole-cells were successfully employed in four consecutive cycles for 2-HPP production under aerobic conditions without any noticeable beads degradation. Moreover, there was no production of benzyl alcohol as an unwanted by-product. Conclusions: Bioconversion by whole P. putida resting cells is an efficient strategy for the production of 2-HPP and other α-hydroxyketones. [ABSTRACT FROM AUTHOR]

The worldwide prevalence of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have become one of the most urgent issues for public health. Thus, it is critical to explore more sustainable methods with less toxicity for the long-term removal of both ARB and ARGs. In this study, we fabricated a novel material by encapsulating zinc oxide (ZnO) nanoflowers and activated carbon (AC) in an alginate biopolymer. When the dosage of ZnO was 1.0 g (≈2 g/L), the composite beads exhibited higher removal efficiency and a slight release of Zn2+ in water treatment. Fixed bed column experiments demonstrated that ZnO/AC alginate beads had excellent removal capacities. When the flow rate was 1 mL/min, and the initial concentration was 107 CFU/mL, the removal efficiency of ARB was 5.69-log, and the absolute abundance of ARGs was decreased by 2.44–2.74-log. Moreover, the mechanism demonstrated that ZnO significantly caused cell lysis, cytoplasmic leakage, and the increase of reactive oxygen species induced subsequent oxidative stress state. These findings suggested that ZnO/AC alginate beads can be a promising material for removing ARB and ARGs from wastewater with eco-friendly and sustainable properties. [ABSTRACT FROM AUTHOR]

The interest in natural sources with high antioxidant powder has recently increased in several sectors. Ionic gelation methods could be used to protect bioactive substances to control the kinetics and release of these ingredients to the food matrix. This study dealt with the evaluation of the antioxidant capacity and scavenging activity of extracts of Hibiscus Sabdariffa L. (HSL) (with 50% ethanol) encapsulated in calcium alginate spheres as a new source for preserving food against oxidative damage. Their antioxidant activity was measured in different o/w emulsions in which HSL spheres reduced the formation of hydroperoxides (~80%) and thiobarbituric-acid-reactive substance products (~20%). The scavenging activity of HSL extracts was measured in different food simulants (water, water acidified with 3% acetic acid, ethanol at 50%, and pure ethanol), and corresponded to 0.20–0.43, 0.31–0.62, and 11.13–23.82 mmol Trolox/mL extract for Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenylpicrylhydrazyl (DPPH), and oxygen radical absorbance capacity (ORAC) assays, respectively. In general, the best antiradical activity was observed in the ethanolic and acidified mediums, in which the highest concentration of released polyphenols ranged from 0.068 to 0.079 mg GAE/mL. This work indicates the potential of alginate spheres for encapsulating antioxidant compounds as an innovative strategy for several industrial applications. [ABSTRACT FROM AUTHOR]

Coculture and whole-cell immobilization have myriad industrial applications for enhancing enzyme production. Using pretreated wheat straw as the sole carbon source, improving glucose isomerase production and cell growth by synthetic bacterial consortia was investigated. Thirteen cocultures were constructed based on the performance and antagonistic activities of monocultures from six cellulolytic soil bacteria. The performance of monocultures immobilized with calcium alginate was also tested. Only five cocultures (A, B, C, G and J) exhibited cell growth and enzyme production synergies. The highest level of synergism (15.17 U/mL) was found in coculture J composed of Mycobacterium sp. MKAL3 (4.06 U/mL) and Stenotrophomonas sp. MKAL4 (3.37 U/mL) with a synergism degree of 2.04. The synergism was unique to growth on wheat straw as it was completely absent in xylose-grown cocultures. The wheat straw degradation synergism could rely on specific compounds released by the MKAL3 strain that promote the activity of the MKAL4 strain and vice versa. However, immobilized strains MKAL1, MKAL2, MKAL3, MKAL4 and MKAL5 improved glucose isomerase production in the wheat straw fermentation process at different sodium alginate concentrations. Immobilization studies of purified glucose isomerases for hydrolysis and saccharification of wheat straw are now being conducted. [ABSTRACT FROM AUTHOR]