Alginate Fractions Research Articles

Preparation, process optimization, and performance study of tea polyphenol-sodium alginate/ethyl cellulose composite microcapsules for green slow-release formaldehyde capture agent

Aiming 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.

Performance of spray-dried Ziziphus jujuba extract using insoluble fraction of Persian gum-sodium alginate and whey protein: Microstructural and physicochemical attributes of micro- and nano-capsules.

The study focused on the impact of the insoluble fraction of Persian gum-sodium alginate and a blend of the insoluble fraction of Persian gum-sodium alginate (IFPG-Al) with whey protein isolate (WPI) on sprayed Ziziphus jujuba extract (JE) powder. The addition of whey protein led to powders with higher moisture (10%), higher solubility (99.19%), and lower powder yield (27.82%). The powders fabricated with WPI depicted the best protection of polyphenolic compounds (3933.4 mg/L) and the highest encapsulation efficiency activity (74.84%). Additionally, they had a higher T g (62.63°C), which indicates more stability of the powders during shelf life. The sphericity of the majority of the particles was noticeable in powders, but multi-sided concavities were visible in the protein-containing particles. Based on the particle size's results, IFPG-Al/WPI capsules fabricated relatively smaller particles (2.54 μm). It can be acknowledged that the presence of protein in particles can bring fruitful results by preserving valuable bioactive compounds.

Adsorption of Sb(III) from Solution by Immobilized Microcystis aeruginosa Microspheres Loaded with Magnetic Nano-Fe3O4

In this study, a renewable and reusable immobilized Microcystis aeruginosa microsphere loaded with magnetic Nano-Fe3O4 composite adsorbent material is designed to study the treatment of wastewater containing heavy metal Sb(III). Through static absorption experiments combined with various characterization methods, this article studies the absorption process and mechanism of Sb(III), and investigates the optimal preparation conditions and environmental influencing factors. The results show that the optimal preparation conditions for immobilized Microcystis aeruginosa microspheres loaded with magnetic Nano-Fe3O4 adsorbent materials are 50.0% mass fraction of Microcystis suspension, 1.5% mass fraction of Nano-Fe3O4, and 2.5% mass fraction of sodium alginate. When the pH of the solution is 4, the reaction temperature is 25 °C, and the adsorbent dosage is 8.5 g/L, the removal rate of Sb(III) is the highest, reaching 83.62% within 120 min. The adsorption process conforms to the pseudo-second order kinetic model and Langmuir adsorption isotherm model, mainly characterized by chemical adsorption and surface complexation. Therefore, the composite material has been proven to be an efficient Sb (III) adsorption material.

Characterization of the Antiproliferative Activity of Sargassum muticum Low and High Molecular Weight Polysaccharide Fractions.

The extract obtained by pressurized hot water extraction from Sargassum muticum, to recover the bioactive compound known as fucoidan, was fractionated using membranes of 100, 50, 30, 10, and 5 kDa, obtaining five retentates and the final permeate. These fractions were characterized for phloroglucinol content, protein content, sulfate content, and trolox equivalent antioxidant capacity (TEAC); apart from oligosaccharides, FTIR and molar mass distribution were also evaluated. Retentates of 100 and 50 kDa showed higher values for phloroglucinol, TEAC, and sulfate content. The rheology of the alginate fraction was also evaluated. Regarding the potential antitumoral activity, all fractions were assessed in MCF-7 cells using a metabolic activity assay based on the reduction of a tetrazolium compound, the most efficient being R100 and R50. Based on the results, these fractions were compared with commercial fucoidans at the same concentrations, and similar results were found. In addition, synergistic cytotoxic effects using two drugs commonly used in breast cancer, cis-Platinum (cis-Pt) and 5-fluorouracil (5-FU), were tested in combination with R100 and R50. Promising results were obtained when the retentate and the drugs were mixed, showing an improvement in the cytotoxicity induced by the chemotherapy.

Sequential and enzyme-assisted extraction of algal bioproducts from Ecklonia maxima

Brown algae are gaining recognition as sources of bio-compounds with diverse properties and potential applications in the food, nutraceutical, and pharmaceutical industries. Compounds such as polyphenols, alginates and fucoidan possess multiple bioactivities, including antidiabetic, antioxidant, anticancer, anti-inflammatory, and antibacterial properties. Conventional extraction methods provide low yields, posing challenges for the industrial applications of biocompounds. However, innovations are rapidly emerging to address these challenges, and one such approach is enzyme-assisted extraction. Furthermore, extracting single compounds undervalues algal biomass as valuable compounds may remain in the waste. Therefore, the aim of our study was to develop a framework for the sequential and enzyme-assisted extraction of various bio-compounds using the same biomass in a biorefinery process. The Ecklonia maxima algal biomass was defatted, and polyphenols were extracted using solid-liquid extraction with aqueous ethanol. The remaining residue was treated with an enzyme combination (Cellic® Ctec 2 and Viscozyme L) to liberate carbohydrates into solution, where an alginate and fucoidan fraction were isolated. A second alginate fraction was harvested from the residue. The phenolic fraction yielded about 11% (dry weight of extract/dry weight of seaweed biomass), the alginate fraction 35% and the fucoidan fraction 18%. These were analysed using a variety of biochemical methods. Structural analyses, including FTIR, NMR and TGA, were performed to confirm the integrity of these compounds. This study demonstrated that a sequential extraction method for various algal bioproducts is possible, which can pave the way for a biorefinery approach. Furthermore, our study primarily employed environmentally and eco-friendly extraction technologies promoting an environmentally sustainable industrial approach. This approach enhances the feasibility and flexibility of biorefinery operations, contributing to the development of a circular bio-economy.

Production and characterization of Ziziphus jujuba extract-loaded composite whey protein and pea protein beads based on sodium alginate-IFPG (insoluble fraction of Persian gum).

This research was aimed at the fabrication of jujube extract (JE)-loaded beads by extrusion, using whey protein isolate (WPI), chickpea protein concentrate (PPC) and a combination of two types of hydrocolloid insoluble fraction of Persian gum (IFPG) and sodium alginate (Al). JE-loaded beads with the highest encapsulation efficiency (10.87%) and polyphenol content (120.8 mg L-1 gallic acid) were obtained using Al-IFPG/PPC at 4 °C. The Al-IFPG, Al-IFPG/WPI and Al-IFPG/PPC beads revealed 5.66, 6.85 and 5.76 mm bead size, respectively, and almost all of them demonstrated a homogeneous and spherical structure. Fourier transform infrared spectroscopy data proved that the stable structure of the Al-IFPG beads was due to hydrogen bonding and electrostatic interactions. The thermostability of beads loaded with JE based on Al-IFPG/WPI was significantly enhanced compared to pure Al-IFPG. Texture evaluation of JE-loaded beads based on Al-IFPG incorporation with WPI revealed an increment in the hardness of beads. This study confirmed the potential of Al-IFPG complex beads for the effective delivery of jujube extract via incorporation into pea and whey proteins and for the expansion of its use in products. © 2023 Society of Chemical Industry.

Orthogonally crosslinked alginate conjugate thermogels with potential for cell encapsulation

Hydrogels with more than one mode of crosslinking have gained interest due to improved control over hydrogel properties such as mechanical strength using multiple stimuli. In this work, sodium alginate was covalently conjugated onto thermoresponsive polyurethanes to prepare hybrid polymers (EPC-Alg) that are responsive to both temperature and Ca2+, forming orthogonally crosslinked hydrogels which are non-toxic to cells. Notably, the crosslinks are fully reversible, allowing for gel strength to be modulated via selective removal of either stimulus, or complete deconstruction of the hydrogel network by removing both stimuli. Higher alginate fractions increased the hydrophilicity and Ca2+ response of the EPC-Alg hydrogel, enabling tunable modulation of the thermal stability, stiffness and gelation temperatures. The EPC-Alg hydrogel could sustain protein release for a month and encapsulate neural spheroids with high cell viability after 7-day culture, demonstrating feasibility towards 3D cell encapsulation in cell-based biomedical applications such as cell encapsulation and cell therapy.

The multilayered emulsion-filled gel microparticles: Regulated the release behavior of β-carotene

This present work underlined the influence of oil/water ratio on the delivery efficiency of multilayered emulsion-filled gel microparticles for β-carotene (BC). Based on electrostatic interactions and ion gelation techniques, the secondary emulsion and the multilayered emulsion-filled gel microparticles were utilized to improve the encapsulation efficiency (EE) and release ability of BC. The results revealed that the secondary emulsion significantly improved the EE of BC, and the degree of droplet aggregation decreased as the oil/water ratio increased. When the mass fraction of sodium alginate exceeded 0.08% (w/v), the particle size and ζ-potential of microparticles tended to be stable, the wrapping capacity of protein was more than 90%. Release studies indicated that these microparticles were regulated by different release kinetics at different pHs, which greatly improved the stability of BC with excellent sustained release. Thus, the multilayered emulsion-filled gel microparticles have a favorable controlled release for BC. • The degree of aggregation of secondary emulsion droplets was impacted by oil/water ratio. • The secondary emulsions significantly improved the encapsulation efficiency of BC. • The multilayer emulsion-filled gel microparticle showed different release kinetics at different pHs. • The multilayered emulsion-filled gel microparticles could sustained release BC.

3D-bioprinted vascular scaffold with tunable mechanical properties for simulating and promoting neo-vascularization

Alternative artificial vessels with tissue-matching mechanical and biological performance have been continuously taking great attention in bioengineering. However, it is challenging to take into account both mechanical and biological properties in formulating a hydrogel material. In the current study, a composite hydrogel ink based on geltain-methacryloyl (GelMA) and sodium alginate (SA) was prepared by a two-step polymerization process, and its fast shaping was realized by stabilizing the alginate fraction in calcium ion bath as well as the photo-crosslinking of GelMA. Mechanical properties of the transparent 3D printing GelMA/Gelatin/SA blood vessels were determined by testing their stretching and resilience performance. Based on Von Mise stress simulation using Ansys, strain of the artificial blood vessels reached 147% and the elastic Young’s modulus reached approximately 224 ​kPa in the optimal hydrogel formulation, matching well with capability of enduring certain blood pressure encountered in real tissue. A selective and uniform permeability of hydrogel tubes was presented by using small molecules and human red blood cells, meanwhile excellent hemolysis, cell viability, and proliferation ability were also verified. Based on the results of in vitro assessment and the in vivo transplantation in SD rats, our proposed GelMA/Gelatin/SA vessels, with tissue-matching mechanical properties and their ideal biodegradation behavior, promoted neo-vascularization capacity and showed promising potential in producing an artificial blood vessel.

Optimization of Preparation Process of Lichi Polyphenols Microcapsules and Its Characteristic Analysis

Microcapsules of lichi polyphenols were prepared by complex coacervation method with sodium alginate and chitosan as wall materials, improving the stability of lichi polyphenols. With embedding rate as index, the preparation conditions were optimized by orthogonal experiment, and its in vitro release properties, thermal stability, antioxidant activity were investigated. The results showed that the optimum preparation process of lichi polyphenols was as follows: the mass fraction of sodium alginate, calcium chloride, chitosan and lichi polyphenols were 3.5%, 3%, 2%, 0.8%, embedding time was 1 h. The obtained microcapsules exhibited a uniform particle size and high embedding rate of 95.74%. The microcapsules had great target-releasing behavior in simulated intestinal fluid (pH6.86), the release rate of polyphenols was 19.66% and the ABTS+ free radicals scavenging rate was 20.30% at 3 h. Compared with the unembedded lichi polyphenols, the microcapsules had higher polyphenols retention rate at the same condition of temperature (increased by 2.09%～3.34%), which showed that the microcapsulation of lichi polyphenols could effectively improve the thermal stability of lichi polyphenols.

Synthesis, process optimization and characterization of gold nanoparticles using crude fucoidan from the invasive brown seaweed Sargassum muticum

Crude fucoidans from Sargassum muticum obtained by hot water extraction at 40–80 °C were used for the synthesis of gold nanoparticles (AuNPs). The effect of operation temperature on the yield and properties of the extract was determined. The alginate fraction partially coextracted precipitated as calcium alginate and showed rheological properties slightly lower than those of commercial alginates reported elsewhere. The fraction of fucoidan with a larger amount of sulfate, obtained at 60 °C (45% saccharide, 22% fucose, 24% sulfate), also contained 8.5% phlorotannins and 3% protein, as well as showing 37% the 2,2-azinobis(3-ethyl-benzothiazoline-6-sulfonate) (ABTS) radical scavenging capacity of Trolox. This soluble product was used for optimization during the synthesis of AuNPs. Several reaction conditions were tested until the obtainment of homogeneous nanoparticles. The characterization of the synthesized nanoparticles was performed employing ultraviolet-visible spectroscopy, Z potential, transmission electron microscopy and Fourier transformed infrared spectroscopy.

Preparation and evaluation of bacillus thuringiensis microcapsules based on biochar

The walnut shell biochar was prepared at high temperature in this experiment. The effect of different biochar on the growth of Bacillus thuringiensis (Bt) were investigated, and biochar with good biocompatibility to Bt was selected and used as an adsorbent to prepare Bt/ sodium alginate/ biochar composite microspheres. The effects of sodium alginate, calcium chloride mass fraction, and biochar addition on the encapsulation rate and the spheroidization rate of microspheres were investigated. The results showed that the optimum preparation conditions were as follows: the mass fractions (w/v) of sodium alginate, biochar, and calcium chloride were 3%, 0.4%, and 2%, respectively. The encapsulation rate and sphericity rate of prepared composite microspheres were 93.50% and 90%, and the diameter was about 1200 μm after drying. Release behavior in water showed that Bt-sodium alginate-biochar microspheres had better sustained release performance than those without biochar.

Alginate–gelatin–Matrigel hydrogels enable the development and multigenerational passaging of patient-derived 3D bioprinted cancer spheroid models

Hydrogels consisting of controlled fractions of alginate, gelatin, and Matrigel enable the development of patient-derived bioprinted tissue models that support cancer spheroid growth and expansion. These engineered models can be dissociated to be then reintroduced to new hydrogel solutions and subsequently reprinted to generate multigenerational models. The process of harvesting cells from 3D bioprinted models is possible by chelating the ions that crosslink alginate, causing the gel to weaken. Inclusion of the gelatin and Matrigel fractions to the hydrogel increases the bioactivity by providing cell-matrix binding sites and promoting cross-talk between cancer cells and their microenvironment. Here we show that immortalized triple-negative breast cancer cells (MDA-MB-231) and patient-derived gastric adenocarcinoma cells can be reprinted for at least three 21 d culture cycles following bioprinting in the alginate/gelatin/Matrigel hydrogels. Our drug testing results suggest that our 3D bioprinted model can also be used to recapitulate in vivo patient drug response. Furthermore, our results show that iterative bioprinting techniques coupled with alginate biomaterials can be used to maintain and expand patient-derived cancer spheroid cultures for extended periods without compromising cell viability, altering division rates, or disrupting cancer spheroid formation.

Study the effect of purified alginate from Pseudomonas aeruginosa on Hep G2 and A549 cell lines.

Alginate was extracted from highest alginate producer of P. aeruginosa 29 isolate, it was determined bybiochemical method (Carbazole-borate assay) and molecular method (PCR), where the amplified algD genesamples showed that clear bands at one level for all the produced isolates and molecular weight were 313 onthe leader scale. partially purified of alginate using gel filtration chromatography (Sephadex G-200) showedthe present of single peak and initial alginate fraction at 17 to last fraction 28 of alginate concentration ,where the highest alginate concentration was at fraction 23 . The cytotoxic effect of different concentrationsof purified alginate on cancer cells (HePG2 , A549 ) and normal cells WRL68 was tested. The result ofhalf-maximal inhibition concentration (IC 50) values of purified alginate treated WRL68 and HepG2 cellsafter 24,48,72 hours of incubation at 37o C were ( 187.8 , 62.0, 83.07) ?g /ml , (102.3, 42.5, 61.03) ?g/mlas respectively. While, the IC50 of purified alginate treated WRL68 and A549 cells after 24,48,72 hours ofincubation at 37oC were ( 126.2, 63.57, 90.31 ) ?g /ml , (117.8, 57.06, 65.7) ?g /ml as respectively.

The brown seaweed Cystoseira schiffneri as a source of sodium alginate: Chemical and structural characterization, and antioxidant activities

Sodium alginates were extracted from brown seaweeds (Cystoseira schiffneri) collected from a Tunisian island (Kerkennah, Sfax) in different seasons (December, April, July and September). The structural features and antioxidant properties of C. schiffneri sodium alginates (CSSA) were characterized. Micro-elementary analysis showed the absence of nitrogen and sulfur in alginate fractions. All alginate isolates were high in uronic acids (47.4–66.4%) and ash (24.3–39.4%). ATR-FTIR, NMR and circular dichroism data showed that all CSSA were of the polyguluronate-type. Weight-average molecular weight determined using high performance size exclusion chromatography showed variations ranging from 4.49 to 1230 kDa. Thermogravimetric analysis suggested that CSSA were stable until 400 °C except for that collected in September, which was observed to only be stable until 200 °C. Antioxidant activity of CSSA from different seasons was measured using DPPH• radical-scavenging, reducing power and Fe2+chelating ability assays. Antioxidant potential of CSSA varied significantly with respect to the season and the main factor controlling antioxidant properties was the molecular mass.

Commodity chemical production from third‐generation biomass: a techno‐economic assessment of lactic acid production

AbstractThe unique characteristics and composition of macroalgae offer new possibilities for the production of bio‐based products such as biofuels and commodity chemicals. The technologies required for processing macroalgae are not currently mature enough, and those that exist are primarily oriented towards the production of biofuels. This study explores a production process to produce lactic acid (LA) from brown algae, designed with a capacity of 11 t h−1 of product. Four scenarios are simulated in Aspen Plus, for the production of polymer‐grade LA, utilizing Laminaria macroalgae as a feedstock. Techno‐economic models are established to investigate the feasibility of these new technologies. Configurations for heat recovery are suggested to maximize productivity, and a minimum viable selling price (MVSP) is calculated for LA to predict an optimal design configuration. The process does not recover investment, when using a composition represented by an avarage value for all the Laminaria sp. Moreover, the percentage difference between the MVSP and the current selling price (SP) is 34%. Nonetheless, when using Laminaria digitata, which comprises of higher carbohydrates, compared to other Laminaria sp, the percentage difference between the MVSP and the SP is estimated to be 28%. If the hypothetical fermentation of alginate is considered, the invested capital is recovered by the 11th year. These results also highlight the need for research into the valorization of the alginate fraction, improving the microorganisms’ ability to metabolize alginate to LA or other relevant products. The development of the respective processes would be a step that the scientific community would be justified in examining. © 2020 Society of Industrial Chemistry and John Wiley & Sons Ltd

Insight into the influence of humic acid and sodium alginate fractions on membrane fouling in coagulation-ultrafiltration combined system

Membrane fouling has become the one of main obstacles for the widespread application of membrane technology in water treatment processes. Coagulation as pretreatment is proven to be effective for the alleviation of membrane fouling. In this study, the influence of humic acid (HA)/sodium alginate (SA) fractions in the structure and resistance of cake layer on the membrane surface was investigated. The presence of SA at an appropriate fraction could facilitate the formation of large and loosely branched flocs and thereby form a more permeable cake layer on the membrane surface due to good bridging and charge neutralization abilities of SA molecules. The particle image velocimetry (PIV) technique was employed for monitoring the dynamic formation process of cake layer under different HA/SA fractions. The cake layer with a higher thickness was observed to be rapidly formed on the membrane surface at the presence of SA in water. According to the theoretical analysis, the membrane fouling in coagulation-ultrafiltration (UF) combined system demonstrated to be highly dependent on the size and intra-porosity of flocs. The fractal dimension of flocs might have an impact on the resistance of cake layer through affecting the porosity of aggregated flocs. The SA molecules could be used as the coagulant aid for effective alleviation of membrane fouling and the improvement of filtration performance in a coagulation-UF combined system.

Composition of polysaccharides and radiosensitizing activity of native and sulfated laminarans from the Tаuуа basicrassa Kloczc. et Krupn

Polysaccharide fractions of alginate, laminarans and fucoidans were obtained from the brown alga Tauya basicrassa. Yields of alginate and laminarans were large (19.7 % and 5.62 %, respectively), whereas the content of fucoidans (0.52 %) was not significant. Alginate and laminarans had typical structures for those substances. Fucoidans were low- and medium-sulfated heterogeneous polysaccharides. The fucoidan fraction 1TbF1 was sulfated fucogalactan containing a backbone from 1,6-linked residues of β-d-galactopyranose with branches at C3 and C4, terminal fucose and galactose residues and fragments from 1,3-; 1,4-; and 1,2-fucose residues. Sulfate groups were found at positions 2 and 4 of fucose, and positions 2, 3 and 4 of galactose residues. Laminaran 2TbL was subjected to a sulfation to obtain the derivative 2TbLS with partial sulfation (46 %) at C2, C4 and C6. It was shown that 2TbL and 2TbLS inhibited colony formation of sensitize-tested colon cancer cells HT-29 and HCT-116 to X-ray radiation.

Synergistic interactions in dilute aqueous solutions between alginate and tropical vegetal hydrocolloids

Encapsulation in alginate beads has always been limited by the leakage due to the too wide distribution of pore sizes. Mixing alginate with other polymers have sometimes reduced the problem. Hydrocolloids from seven tropical vegetal species (barks of Triumfetta cordifolia and Bridelia thermifolia, seeds of Irvingia gabonensis and Beilschmiedia obscura, and leaves of Ceratotheca sesamoides, Adansonia digitata and Corchorus olitorius) were screened for synergistic interactions with alginate in dilute aqueous solution. Mixtures with alginate were made at different volume proportions and deviations from the initial viscosity set at 1 were evaluated. In distilled water, the gums from T. cordifolia, B. obscura, C. sesamoides and C. olitorius presented synergies with alginate. In 2 mM calcium chloride, the seven gums showed positive synergy. Interactions are favored by gum flexibility and the presence of charges, although high charges reduced the interactions. Alginate fraction of maximum viscosity enhancement depends on the ability to conformational order of the gum. The measure by laser diffraction of alginate-gum particles sizes at different fractions showed that the cooperative interactions did not always involve the largest complexes formed in gums associations. The occurrence of these interactions predicts the formation of homogeneous mixed gels at higher polymer and calcium concentrations.

Radical Depolymerization of Alginate Extracted from Moroccan Brown Seaweed Bifurcaria bifurcata

The degradation of alginate extracted from Moroccan Bifurcaria bifurcata has not been fully established to date. In this work, we report the extraction and the characterization of alginate (ASBB) from the brown algae B. bifurcata, as well as the production of oligo-alginates (OGABs) by using a green chemistry process. The depolymerization of ASBB was carried out by controlled radical hydrolysis through our green chemistry process using a hydrogen peroxide (H2O2) catalyst. The molecular weight (Mw) and degree of polymerization (DP) distribution of oligo-alginates (OGABs) obtained were then characterized by HPLC size exclusion chromatography (SEC) and high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Structural characterization revealed that after 6 h of depolymerization of ASBB, we obtained OGABs with Mw ≤ 5.5 kDa and 2 ≤ DP ≤ 24. These results highlight the effectiveness of the controlled radical hydrolysis of alginate to produce good yields of alginate fractions with controlled Mw with a known polymerization degree (DP) and without altering properties of oligo-alginates. Bifurcaria bifurcata can be a potential source of alginate and oligo-alginates given its abundance on the northwest Atlantic coast. The production and characterization of oligo-alginates promote their exploitation in the cosmetic, pharmaceutic, and agriculture fields.