The string of bacteria, Vibrio. sp. QD-5 utilizing alginate, was separated from rotten kelp. The results of genome sequencing showed that the strain QD-5 contained four alginate lyase genes.One of the alginate genes Aly-IV was cloned and linked to the plasmid pET-22b (+). The heterologous expressed alginate lyase aly-IVwas characterized，which possessed the theoretical molecular mass of 62 kDa, and theoretical isoelectric point (pI) of 5.12. - The enzyme aly-IV was purified and the activity reached 1256.78 U/mg, with optimal temperature of 35 ^oC and pH value of 8.9. Nurtured in the temperature below 25 ^oC for 30 minutes, the activity was almost stable. The result also suggested that the activity of enzyme was strongly affected by - NaCl whose optimal concentration was 15 mM in a lab environment The TLC and ESI-TOF-MS analysis suggested that the enzyme aly-IV could degrade sodium alginate and polyG in endo-lytic type, producing monomer, dimer and trimmer. So, aly-IV can also be widely applied to make large scale preparation of alginate oligosaccharides with low degree of polymerization (DP).

To overcome the difficulty of separating bastnaesite from fluorite through the flota-tion technique, the present study examined the suitability of sodium alginate (SA) as a depressant in the flotation process. The effect of SA on the flotation separation of bastnaesite and fluorite was evaluated using micro-flotation tests, zeta potential meas-urements, adsorption density measurements, Fourier infrared spectroscopy, and X-ray photoelectron spectroscopy. The micro-flotation results showed that SA exerted a strongly detrimental effect on fluorite flotation, while slightly affecting bastnaesite flotation. The surface chemistry results revealed that the -COO- and HO- functional groups in SA coordinated with Ca2+ on the fluorite surface, which induced hydro-philicity and hindered the adsorption in the subsequent collector. However, the inter-action of SA with the bastnaesite surface was marginal and did not affect the anchor-ing of the collector on the surface of bastnaesite. Based on these results, the present study proposes a possible model for the interaction of SA on the surfaces of the two minerals, laying a foundation for the flotation separation of bastnaesite from fluorite with SA as an environmentally benign depressant.

(1) In searching for herbal alternatives for treating coccidiosis in turkeys, this trial aimed to evaluate whether minced black garlic (Allium sativa) or turmeric powder (Curcuma longa) or their combination, included in dried alginate beads, were capable of controlling clinical coccidiosis in turkey male poults. (2) Four groups of 15 twelve-day-old turkey poults per group were set and rose in this trial until the end of week six. Groups were: CTR = control untreated turkeys; GAR = turkeys fed 4% of their diet with minced garlic included in dried alginate beads; CUR = treated fed 4% powder Curcuma, also prepared as dried alginate beads; and G.C. = turkeys fed 8% of their diet with the mixture of minced black garlic plus powder Curcuma (4% of each one), entrapped in dried alginate beads. Treatments were incorporated as feed-dressing, considering their mean feed intake. (3) Results reveal that turkeys in group G.C. showed a significant decrease in oocysts per gram of feces during the first six weeks of age compared to values found in the CTR group and the other treatments. These results identify that in turkey poults, there is a statistically significant anticoccidial activity of the combination of minced garlic plus powder Curcuma, included in alginate beads and administered as 4% of their feed intake. Additionally, better productive variables were recorded for this combination compared to the other three groups (P <0.05). (4) The use of vehicles specifically designed for the digestive tract of turkeys may improve the effectiveness of plant extracts for the control of coccidiosis.

The effect of chemical degradation of a sodium alginate solution and the possibility of encapsulation of paprika oleoresin were investigated. To produce sodium alginate oligomers, a depolymerization process was performed using hydrogen peroxide as a decomposition factor. The characteristics of the samples were obtained by measuring the contact angle of the surface, the surface tension of solutions, as well as thermal decomposition in thermo - gravimetric analysis. The obtained solution of alginate oligomers served as the carrier material for immobilization of capsaicin. Capsules were prepared by ionic gelation using a calcium chloride solution as a crosslinking agent. In this way, capsules without and with the core (capsaicin) were prepared and their ability to scavenge free radicals (DPPH) and iron-reducing properties (FRAP) were determined. The stability of the capsules was examined under conditions of the gastric and small intestine. It was found that alginate oligomers can be used in the encapsulation of bioactive compounds and the efficiency is above 80%. Capsule production from alginate oligomers affected their thermal stability. The use of alginate derivatives as a carrier increases the antioxidant properties of the finished product, as well as its ability to reduce iron ions. The use of alginate oligomers as a coating material prevents the active substance from being released too early in the conditions of the small intestine, prolongs the stability of the capsules, and supports their durability in gastric conditions.

The present study focused on the development of gel-based capsules from sodium alginate and different berries fresh juice: chokeberry, sea buckthorn, and blueberry. Obtained through extrusion method, the macrocapsules were added into yoghurt, a well-known and consumed dairy product. In order to establish the changes that can occur into the food product, the samples were tested during 7, respectively 15 days storage in refrigeration conditions. According to the results, the antioxidant activity increased during storage and gels can represent a good option for bioactive substances’ encapsulation. Sensorial analysis performed indicated that consumers are open to consuming yoghurt berries capsules and, according to the results observed into scientific literature, they no longer rejected the product due to bitterness and sourness of sea buckthorn or aronia.

Water pollution is regarded as a dangerous problem that needs to be resolved right away. This is largely due to the positive correlation between the increase in global population and waste production, especially food waste. Hydrogel beads based on sodium alginate (Alg) and pomegranate fruit peels (PP) were developed for the adsorption of Safranin O dye (SO) in aqueous solutions. The obtained Alg-PP beads were widely characterized. The effects of the contact time (0-180 min) and initial concentration (10-300 mg/l), the initial pH (2-10), the adsorbent dosage (1-40 g/l) and the temperature (293-333 K) were investigated through batch tests. The data proved that the adsorption kinetics of SO reached equilibrium within 30 min and up to 180 min. The adsorption data of SO onto synthesized beads follow the pseudo second-order model. The experimental data fitted very well to both Freundlich and Langmuir models. The maximum adsorption capacity of Alg-PP could reach 8.99 mg/g at 293 K. Calculation of Gibbs free energy and enthalpy indicated that adsorption of SO onto Alg-PP is spontaneous and endothermic. Finally, analysis of diffusion and mass transport phenomena were presented. The reported results revealed that the Alg-PP beads could be used as a novel natural adsorbent for the removal of cationic dye pollutants from aqueous environments.

In this study, fig leaves, zeolite and alginate were used to prepare a biocomposite for the adsorption of Pb(II) ions from aqueous solutions. Effects of various parameters on the biosorption process such as pH, temperature, initial lead concentration and contact time have been investigated. Maximum uptake of Pb(II) ions (85%) has been achieved at pH 6, with 25 mg/L of initial concentration and at a temperature of 288.15 K. Among the applied models, the data correlated well with Freundlich and D-R models and it was established that the biosorption was physical in nature. The amount of adsorbed lead per gram of sorbent was found to be 150.3 mg/g. Thermodynamic parameters showed the exothermic heat of biosorption and the feasibility of the process. Results have suggested that the prepared biosorbent possesses promising biosorption potential.

Alginate-gelatin (Alg-Gel) hydrogels have been used experimentally but not clinically associated with mesenchymal stromal / stem cells (MSCs) to guide bone tissue formation. One of the main challenges for its clinical application is optimizing Alg-Gel stiffness to guide osteogenesis. In this study, we investigated how Alg-Gel stiffness could modulate the dental pulp stem cell (DPSCs) attachment, morphology, proliferation, and osteogenic differentiation, identifying the optimal condition to uncouple osteogenesis from the other cell behaviors. An array of Alg-Gel hydrogels was prepared by casting different percentages of Alg and Gel being crosslinked with 2 % CaCl2. We selected two hydrogels, one with 11± 1 kPa called “low” stiffness and one with 55 ± 3 kPa called “high” stiffness. Hydrogel analyses showed that the average swelling rates were 20 ± 3% for low and 35 ± 2% for high hydrogels. The degradation percentage was 47 ± 5% and 18 ± 2% for low and high hydrogels, respectively. Both hydrogel types showed homogeneous surface shape and pro-tein (Alg-Gel) interaction with CaCl2 as assessed by FTIR-ATR and XPS. Cell culture showed good adhesion of the DPSCs to the hydrogels and proliferation. Furthermore, better osteogenic activity was obtained with high-stiffness hydrogels. In summary, this study confirms the possibility of characterizing and optimizing the stiffness of alginate-gelatin gel to guide osteogenesis in vitro without altering other cellular properties of DPSCs.

The results of the investigation showed that second-order kinetics govern the adsorption process, and the corresponding rate constants were found. To evaluate the parameters related to the adsorption process, the adsorption equilibrium was examined using a variety of mathematical models, such as the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models. The Langmuir isotherm was found to be the best appropriate among all models for describing the adsorption of Cu2+ and Ni2+ ions using bio-nanocomposite beads. The positive values of ΔH° indicate that the adsorption is physical and endothermic, in agreement with experimental results. The negative value of ∆G° shows that the adsorption process is spontaneous. Positive ΔS° values indicate increased randomness at the solid/liquid interface, during adsorption of Cu2+ and Ni2+ cations onto the engineered bio-nanocomposite. The maximum adsorbed amounts of metal ions by the bio-nanocomposite used were 370.37 mg/g for Ni2+ and 454.54 mg/g for Cu2+ from single system. For the binary system, according to the Langmuir isotherm, the maximum adsorbed amounts of Ni2+ and Cu2+ were 357.14 mg/g and 370,37 mg/g, respectively. There is proof that Alginate-Moroccan clay bio-nanocomposites can serve as a different, less expensive source of sorbents for the removal of metal ions from single and binary systems.

The objective of this study aimed to develop biodegradable calcium alginate microspheres carrying doxorubicin (Dox) at the micrometer-scale for sustained-release and the capacity of pH regulatory for transarterial chemoembolization. Ultrasonic atomization and CaCl2 cross-linking technologies were used to prepare the microspheres. A 4 by 5 experiment was first designed to identify imperative parameters. The concentration of CaCl2 and the flow rate of the pump were found to be critical to generate microspheres with a constant volume median diameter (~ 39 m) across 5 groups with different alginate:NaHCO3 ratios using each corresponding flow rate. In each group, the encapsulation efficiency was positively correlated to the Dox-loaded efficiency. Fourier-transform infrared spectroscopy showed that NaHCO3 and Dox were step-by-step incorporated into the calcium alginate microspheres successfully. Microspheres containing alginate:NaHCO3 = 1 exhibited rough and porous surfaces, high Young’s modulus and hardness. In each group with the same alginate:NaHCO3 ratio, the swelling rates of microspheres were higher in PBS containing 10% FBS compared to those in PBS alone. Microspheres with relative high NaHCO3 concentrations in PBS containing 10% FBS maintained better physiological pH and higher accumulated Dox release ratios. In two distinct hepatocellular carcinoma-derived cell lines, treatments with microspheres carrying Dox demonstrated that the cell viabilities decreased in groups with relative high NaHCO3 ratios in time- and dose-dependent manners. Our results suggested that biodegradable alginate microspheres containing relative high NaHCO3 concentrations improved the cytotoxicity effects in vitro.

The effects of octadecylamide of alginic acid (amidated alginate) and tetrahydrolipstatin on serum and hepatic cholesterol, and the faecal output of fat and sterols were compared in rats. Amidated alginate is a sorbent of lipids, tetrahydrolipstatin is inhibitor of pancreatic lipase. Rats were fed diets containing cholesterol and palm fat at 10 and 70 g/kg, respectively. Palm fat was provided by coconut meal. Amidated alginate at 40 g/kg diet significantly decreased serum total cholesterol, LDL and hepatic cholesterol, hepatic lipids, and increased faecal output of fat and coprostanol. Tetrahydrolipstatin at 300 mg/kg diet significantly decreased LDL cholesterol, hepatic lipids and increased faecal output of fat. The intake of feed was not significantly influenced, however the weight gains in rats fed amidated alginate was lower than in rats of the control group. Both amidated alginate and tetrahydrolipstatin modified fatty acid profile in excreta lipids. Concentrations of saturated fatty acids were decreased and that of unsaturated fatty acids were increased. Despite different mode of action, amidated alginate and tetrahydrolipstatin were equally efficient in the removing dietary fat from the body.

The aim of this work is to develop a method to produce spherical biopolymer-based aerogel particles, which is capable for scale up in the future. Therefore, jet cutting method is suggested. Amidated pectin and sodium alginate were used as precursor (1–3 wt. % solution) for particle production via jet cutting. Gelation was realized via two methods: internal setting method (using calcium carbonate particles as cross-linker and citric and acidic acid for pH adjustment) and diffusion method (in calcium chloride solutions). Gel particles were subjected to solvent exchange to ethanol and consequent supercritical drying with CO₂. Spherical aerogel particles with narrow particle size distribution in the range of 400 to 1500 µm and with specific surface area of around 500 m²/g could be produced. Overall, it can be concluded that jet cutting method is suitable for aerogel particle production, although the shape of the particles is not perfectly spherical in all cases. However, parameter adjustment might lead to even better shaped particles in further work. Moreover, the biopolymer-based aerogel particles synthesized in this study were tested as humidity absorber in drying units for home appliances, particularly for dishwashers. It could be shown that for several cycles of absorption and desorption of humidity aerogel particles are stable with an absorption capacity of around 20 wt. %.

Alginate, a biopolymer promising in food, biomedical, pharmaceutical, and electronic materials industries, is characterized by its biodegradability, biocompatibility, low toxicity, and gel-forming properties. It is most abundantly found in brown algae. However, conventional dilute acid and alkali extraction methods face limitations in commercialization due to their long processing time, low throughput, and high solvent requirements. In this study, a microwave-assisted extraction (MAE) process for sodium alginate was designed to improve extraction efficiency. Solid/liquid ratio, extraction temperature, and extraction solvent concentration were major variables affecting sodium alginate extraction from Undaria pinnatifida(sea mustard). They were then statistically optimized using response surface methodology. Under optimal conditions (13.27 g/L, 91.86 ℃, 2.51 %(w/v), and 15 min), the yield was 38.41 %, which was 93.43 % of the theoretical content of sodium alginate in Undaria pinnatifida. Our work has confirmed the productivity and industrial feasibility of efficient extraction of sodium alginate from marine biomass, and we hope that it will serve as an encouraging case for the application of biopolymers as one of the desirable options for alternative petrochemicals to construct a sustainable society.

Bacteriotherapy is emerging as a strategic and effective approach to treat infections by providing putatively harmless bacteria (i.e., probiotics) as antagonists to pathogens. A proper delivery of probiotics or their metabolites (i.e., post-biotics) can avail itself of biomaterial encapsulation by innovative manufacturing technologies. This review paper aims at providing the most recent biomaterial-assisted strategies proposed to treat infections or disbiosis using bacteriotherapy. We revised the encapsulation processes across multiscale biomaterial approaches, which could be ideal to target different tissues and suit diverse therapeutic opportunities. Hydrogels, and in particular polysaccharides, are the focus of this review, as they have been reported to better sustain vitality of the live cells incorporated. Specifically, the approaches for fabricating hydrogel-based devices with increasing dimensionality (D), namely, 0D (i.e., particles), 1D (i.e., fibers), 2D (i.e., fiber meshes), and 3D (i.e., scaffolds) endowed with probiotics, were detailed by describing their advantages and challenges, along with a future overlook in the field. Electrospinning, electrospray and 3D bioprinting were investigated as new biofabrication methods for probiotic encapsulation within multidimensional matrices. Finally, examples of biomaterial-based systems for cell and post-biotic release were reported.

Hydrogels (gels) are attractive tools for tissue engineering and regenerative medicine due to their potential for drug delivery and ECM-like composition. In this study, we use rheology to characterize GelMA/alginate gels loaded with human platelet lysate (PL). We then characterize these gels from a physicochemical perspective and evaluate their ability to transport PL proteins, their pore size, and their rate of degradation. Finally, their biocompatibility is evaluated. We describe how alginate changes the mechanical behavior of the gels from elastic to viscoelastic after ionic (calcium-mediated) crosslinking. In addition, we positively report the release of PL proteins and relate it to the degradation profile of the gels and the biocompatibility of the gels. Thus, the developed gels represent attractive substrates for both cell studies and bioactive materials.

In this study, we had investigated the use of high-pressure homogenization (HPH) as a novel pretreatment method for the extraction of sodium alginate (SA) from Laminaria japonica. Our results demonstrated that under optimal condition of 100 MPa HPH pressure, 4 cycles, pH 6.0, and 0.5% ethylene diaminetetra acetic acid tetrasodium salt (EDTA) concentration (w/v) for 3.0 hours, the extraction yield of HPH reached 34%, which was higher than that achieved by previous methods such as complex enzyme hydrolysis (CE), ultrasonic-assisted extraction (UAE), and complex enzyme-ultrasonic combined method (CE-UC). To further characterize the extracted SA, we conducted a comprehensive analysis using SEM, FTIR, MRS, NMR, XRD, TGA, and T-AOC assay. Our findings revealed the following: 1) HPH treatment significantly disrupted the structure of L. japonica cells and reduced their crystallinity to 76.27%, the lowest among all pretreatment samples; 2) the extracted SA had a greater tendency to form elastic gels; and 3) the antioxidant activity of HPH-extracted SA reached 0.02942 mgVceq∙mg-1, which was the highest among all tested methods. Based on these results, we concluded that HPH extraction not only increased the yield of SA but also enhanced its antioxidant activity.

Alginate films (2% w·v-1) were prepared with varying concentrations (5-20% w/w) of citric acid and aqueous grape seed extract (GSE) filtrate (11.66 ± 1.32 g GAE/L) by the solvent-evaporation method. Crosslinking alginate via ester bonds (FTIR analysis) with citric acid up to 10% (w/w) led to a 33% increase in tensile strength, a 34% reduction in water vapor transmission rate (WVTR), and had no impact on elongation at break. Crosslinking alginate with citric acid in presence of GSE increased the tensile strength by 17%, decreased WVTR by 21%, and significantly improved DPPH scavenging activity. Moreover, after incubation for 24 h at 37°C, the film-forming solutions exhibited increased antimicrobial activity, resulting in 0.5 and 2.5-log reductions for Escherichia coli and Staphylococcus aureus, respectively, compared to the values obtained without the addition of GSE. The stronger inhibitory effect observed against Gram-positive bacteria can be attributed to the unique composition and structure of their cell walls, which create a barrier that restricts the penetration of polyphenols into the cells. pH adjustment of the GSE film-forming solution from 2.0 to 10.0 shifted the UV/VIS absorption spectra, resulting in a colour change from yellow to red. The findings of this study have showcased the potential of combining GSE and citric acid to enhance the functionality and bioactivity of alginate films for applications in smart food packaging.

Management of chronic inflammation and wounds has always been a key issue in the pharmaceutical and healthcare sector. Curcumin (CCM) is an active ingredient extracted from turmeric rhizomes that has antioxidant, anti-inflammatory, and antibacterial activities, thus showing significant effectiveness toward wound healing. However, its shortcomings such as poor water solubility, poor chemical stability and fast metabolic rate limit its bioavailability and long-term use. In this context, hydrogels appear to be a versatile matrix for carrying and stabilizing drugs due to the biomimetic structure, soft porous microarchitecture, and pleasant biomechanical properties. The drug loading/releasing efficiencies can also be controlled by use of highly crystalline and porous metal organic frameworks (MOFs). Here, a flexible hydrogel composed of sodium alginate (SA) matrix and CCM-loaded MOFs was constructed for long-term drug release and antibacterial activity. The morphology and physicochemical properties of composite hydrogels were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet visible spectroscopy (UV-Vis), Raman spectroscopy and mechanical property tests. The results showed that the composite hydrogel was highly twistable and bendable to mechanically comply with human skin. The as-prepared hydrogel could capture efficient CCM for slow drug release as well as effective killing of bacteria. Therefore, such composite hydrogel is expected to provide a new management system for chronic wound dressings.

Polysaccharides such as alginate and gellan gum are biocompatible and easily accessible biopolymers with excellent properties to produce microparticles as drug delivery systems. However, the production methods often fail in reproducibility, compromising the translational potential of such systems. In this work, microparticles made from gellan gum and alginate were optimized using the coaxial air flow method, and an inexpensive and reproducible production method. A Design of Experiments was used to identify the main parameters that affect the microparticle’s production and optimization, focusing on the diameter and dispersibility. Airflow was the most significant factor for both parameters. Pump flow affected the diameter, whilst the gellan gum/alginate ratio affected dispersibility. After optimization, microparticle swelling, drug entrapment and release profile were analyzed at two pH, 7.4 and 6.5. Using methylene blue as a model drug, higher encapsulation and swelling indexes were obtained at pH 7.4, whilst a more pronounced release occurred at pH 6.5. The microparticle release profiles were studied by resorting to well-known models, showing a Fickian type release. The developed microparticles show promising results as drug-delivery vehicles for biomedical applications.

Hydrogels obtained from the combination of different polymers are an interesting strategy for the development of controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using different concentration of the components. The hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and swelling degree; betamethasone release as well as the in vitro cytocompatibility with chondrocytes and fibroblast cells were also evaluated. Scanning electron microscopy confirmed the porous surface morphology of the hydrogels in all cases. The swelling percent was determined at different pH and was observed to be pH-sensitive. The controlled release behavior of betamethasone from the matrices was investigated in PBS media (pH = 7.4) and the drug was released in a controlled manner up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay shown that almost all hydrogels are cytocompatibles and an increase the proliferation in both cell types after one week of incubation was observed by Live/Dead® assay. These results demonstrate that these hydrogels are attractive materials for pharmaceutical and biomedical applications due to their characteristics, their release kinetics and biocompatibility.

The purpose of this study was to investigate the effect of chitosan (CS) and Alginate (Alg) polymers concentrations and CaCl2 concentration on metronidazole (MET) drug loading (LE), size particles and zeta potential. Nanocomposites were prepared by ionotropic pregelation method. A (21 *31 *21) *3= 36 full factorial design (FFD) was used to predict statistical equation and responses. The MET-CS-AlgNPs nanocomposites were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscope and in vitro drug release studies. All data indicated the presence of drug into MET-CS-AlgNPs nanocomposites. The release profile of MET-CS-AlgNPs nanocomposites was found to be sustained

Hydrogels are three-dimensional crosslinked materials known for their ability to absorb water, exhibit high flexibility, biodegradability, biocompatibility, and mimic properties of different tissues in the body. However, their application is limited by inherent deficiencies in mechanical properties. To address this issue, reduced graphene oxide (rGO) and tannins (TA) were incorporated into alginate hydrogels (Alg) to evaluate the impact of the concentration of these nanomaterials on mechanical and adhesive, as well as cytotoxicity and wound healing properties. Tensile mechanical tests demonstrated improvements in tensile strength, elastic modulus, and toughness upon the incorporation of rGO and TA. Additionally, the inclusion of these materials allowed a greater energy dissipation during continuous charge-discharge cycles. However, the samples did not exhibit self-recovery under environmental conditions. Adhesion was evaluated on pig skin, revealing that higher concentrations of rGO led to enhanced adhesion, while the concentration of TA did not significantly affect this property. Moreover, adhesion remained consistent after 10 adhesion cycles, and contact time before the separation between the material and the surface did not affect this property. The materials were not cytotoxic and promoted healing in human fibroblast model cells. Thus, an Alg/rGO/TA hydrogel with enhanced mechanical, adhesive, and wound healing properties was successfully developed.

Azobenzene photoswitches are fundamental components in contemporary approaches aimed at light-driven control of intelligent materials. Significant endeavors are directed towards enhancing the light-triggered reactivity of azobenzenes for such applications and obtaining water-soluble molecules able to act as crosslinkers in a hydrogel. Here, we report the rational design and the synthesis of azobenzene/alginate photoresponsive hydrogels endowed with fast reversible sol-gel transition. We started with the synthesis of three cationic azobenzenes (AZO A, B, and C) and then incorporated them in sodium alginate (SA) to obtain photoresponsive supramolecular hydrogels (SMHGs). The photoresponsive properties of the azobenzenes were investigated by UV-Vis and ¹H NMR spectroscopy. Upon irradiation with 365 nm UV light, the azobenzenes demonstrated efficient trans-to-cis isomerization, with complete isomerization occurring within seconds. The return to the trans form took several hours, with AZO C exhibiting the fastest return, possibly due to higher trans isomer stability. In the photoresponsive SMHGs, the minimum gelation concentration (MGC) of azobenzenes was determined for different compositions, indicating that small amounts of azobenzenes could induce gel formation, particularly in 5 wt% SA. Upon exposure to 365 nm UV light, the SMHGs exhibited reversible gel-sol transitions, underscoring their photoresponsive nature. This research offers valuable insights into the synthesis and photoresponsive properties of cationic, water-soluble azobenzenes, as well as their potential application in the development of photoresponsive hydrogels.

In this work, a colorimetric indicator based on gold nanoparticles (AuNP) and a biodegradable and eco-friendly polymer (sodium alginate, Alg.), has been developed, for the real-time detection of fish spoilage products. AuNP and colorimetric indicator were characterized by: UV-Vis, FTIR spectroscopies, TGA, DSC, XRD, TEM, and colorimetry. The UV-Vis spectrum and TEM showed the successful synthesis, the spherical shape, and the size of AuNPs. Results indicated color changes of the indicator in packaged fish on day 9 of storage at refrigerated temperature (5ºC). These results showed the successful application of colorimetric indicator in the detection of TVB-N in packaged fish.

Addressing the growing need for effective and environmentally friendly fungicides in agricul-ture, this study explored the potential of alginate microparticles loaded with metal ions as a novel approach to combat fungal pathogens. Novel alginate microparticles (microspheres and microcapsules) loaded with zinc or simultaneously with zinc and silver ions were prepared and physicochemically characterized (microparticle size, morphology, topography, encapsulation efficiency, loading capacity, and swelling behavior). Investigation of molecular interactions in microparticles using FTIR-ATR spectroscopy exhibited complex interactions between all con-stituents. Fitting to the simple Korsmeyer-Peppas empirical model revealed the rate-controlling mechanism of zinc and silver ions release from microparticles is Fickian diffusion. Lower values of the release constant k imply a slower release rate of Zn or Ag ions from microcapsules com-pared to that of microspheres. The antimicrobial potential of the new formulations against the fungus Botrytis cinerea was evaluated. When subjected to tests against the fungus, microspheres and microparticles loaded with both zinc and silver ions effectively reduced its growth and al-tered the fungal hyphal structures well as exhibited superior antifungal activity. The results showed the potential of these novel microparticles as potent fungicides in agriculture.

Translational medicine requires facile experimental systems to replicate the dynamic biological systems of diseases. Drug approval continues to lag, partly due to incongruencies in the research pipeline that traditionally involve 2D models, which could be improved with 3D models. The bone marrow (BM) poses challenges to harvest as an intact organ making it difficult to study disease processes such as breast cancer (BC) survival in BM, and to effective evaluation of drug response in BM. Furthermore, it is a challenge to develop 3D BM structures due to its weak physical properties, and complex hierarchical structure and cellular landscape. To address this, we leveraged 3D bioprinting to create a BM structure with varied methylcellulose (M):alginate (A) ratios. We selected hydrogels containing 4% (w/v) M and 2% (w/v) A, which recapitulates rheological and ultrastructural features of the BM while maintaining stability in culture. This hydrogel sustained the culture of two key primary BM microenvironmental cells found at the perivascular region, mesenchymal stem cells and endothelial cells. More importantly, the scaffold showed evidence of cell autonomous dedifferentiation of BC cells to cancer stem cell properties. This scaffold could be the platform to create BM models for various disease and also for drug screening.

Azo dyes are the most widely used synthetic dyes in the printing and dyeing process. However, the discharge of untreated azo dyes poses potential threat for human health and aqueous ecosystem. Herein, we fabricated a novel heterogenous catalyst - activated carbon fiber-supported ferric alginate (FeAlg-ACF) . Together with peroxymonosulfate (PMS) and visible light, this photocatalytic oxidation system was used to remove an azo dye - azophloxine. The results indicated that the proposed catalytic oxidation system can remove 100% azophloxine within 24 min, while under the same system, the removal rate was only 92 % and 84 % when ferric alginate was replaced with ferric citrate and ferric oxalate respectively, which showed the superiority of activated carbon fiber-supported ferric alginate. The degradation of azophloxine is achieved by the active radicals (SO4•− and •OH) released from PMS and persistent free radicals from activated carbon fiber. After treating for 24 min, the total organic carbon of azophloxine solution (50 μmol/L) decreased from 1.82 mg/L to 79.3 μg/L and the nitrate concentration of ions increased from 0.3 mg/L to 8.6 mg/L. That is, up to 93.5% azophloxine molecules were completely degraded into inorganic compounds. Consequently, potential secondary contamination by intermediate organic products during catalytic degradation was prohibited. The azophloxine removal ratio was kept almost constant after seven cycles, indicating the recyclability and longevity of this system. Furthermore, the azophloxine removal was still promising at high concentrations of Cl-, HCO3-, CO32-. Therefore, our proposed system is potentially effective to remove dye pollutants from seawater. It provides a feasible method for the development of efficient and environmental friendly PMS activation technology combined with FeAlg-ACF, has significant academic and application value.

The potential of sodium alginate (ALG) and gum arabic (GA) as wall polymers for L-ascorbic acid (AA) encapsulation as a tool for their preservation against the thermo-oxidative degradation was investigated. The influence of such polymers used as wall material on the AA-content, size, encapsulation efficiency, encapsulation yield and thermo-oxidative stability were evaluated. The AA-microparticles were obtained using the spray-drying technique. An experimental Taguchi design was employed to assess the influence of the variables in the encapsulation process. The microparticles morphology and size distribution were characterized by scanning electron microscopy and laser diffraction. The thermal stability of AA microparticles was studied by differential scanning calorimetry and thermogravimetry analysis. This work points out the viability to encapsulate AA using GA and ALG through a spray-drying process. In general, a product yield ranging from 35.1% to 83.2% and an encapsulation efficiency above 90% was reached. Spherical microparticles with a smooth surface were obtained with a mean diameter around 6 μm and 9 μm for the those prepared with GA and ALG, respectively. The thermo-oxidative analysis showed that both polymers allow maintaining AA stable up to 188 °C, which is higher than the traditional processing temperature used in the fish feed industry.

Alginate is naturally occurring polymer derived from brown algae biomass, which has found numerous applications in various fields. Chemical modification of alginate is widely used to improve the physicochemical properties of alginate and to provide new potential for various applications. In this article, we modified alginate with L-DOPA, using periodate oxidation and reductive amination, in order to be get more suitable biopolymer for biocatalysts immobilization and hydrogel formation. Obtained modified alginate was used for immobilization of laccase on cell walls. For this purpose, laccase from Streptomyces cyaneus was expressed on the surface of Saccharomyces cerevisiae EBY100 cells. Obtained cell wall laccase was immobilized within L-DOPA-alginate beads, by crosslinking of L-DOPA-alginate with calcium ions and laccase. The effect of additional crosslinking of beads by green light induced photopolymerization with eosin Y was investigated. The immobilized laccase systems were used for dye decolorization and also investigated in multiple treatment processes of dye decolorization. Beads with L-DOPA-alginate with higher degree of modification (5.0 mol%) showed higher enzymatic activity and better de-colorization efficiency compared to those with lower degree of modification (2.5 mol%). Obtained immobilized biocatalysts are suitable for the decolorization of dye Evans Blue due to their high efficiency and reusability.

Innovations in drug delivery systems are crucial for enhancing therapeutic efficiency. Our research presents a novel approach based on Electro-fluid dynamic atomization (EFDA) to fabricate core-shell monophasic particles (CSMp) from sodium alginate blends of varying molecular weights. This study explores the morphological characteristics of these particles in relation to material properties and process conditions, highlighting their potential in drug delivery applications. A key aspect of our work is the development of a mathematical model that simulates the release kinetics of small molecules, specifically sodium diclofenac. By assessing the diffusion properties of different molecules and gel formulations through transport and rheological models, we have created a predictive tool for evaluating the efficiency of these particles in drug delivery. Our findings underscore two critical independent parameters for optimizing drug release: the external shell thickness and the diffusivity ratios within the dual layers. This allows for precise control over the timing and intensity of the release profile. The study advances our understanding of EFDA in the fabrication of CSMp and offers promising avenues for enhancing drug delivery systems by tailoring release profiles through particle characteristic manipulation.

A novel chemically cross-linked hydrogel was prepared through the utilization of the nor-bornene (Nb)-methyl tetrazine (mTz) click reaction, derived from carboxymethyl cellulose (CMC) and alginate (Alg). The hydrogel was designed to generate reactive oxygen species (ROS) from NIR-dye, indocyanine green (ICG) for a combined photothermal and photodynamic ther-apy (PTT/PDT). The cross-linking of Nb and mTz moieties occurred via an inverse elec-tron-demand Diels-Alder reaction under physiological conditions avoiding the need for a cata-lyst. The resulting hydrogels exhibited viscoelastic properties (G′ ~ 492-270 Pa) and high porosi-ty. The hydrogels were found to be injectable with tunable mechanical characteristics. The ICG encapsulated hydrogels demonstrated ROS generation ability under NIR exposure. The ROS production was investigated through DPBF assays to access photodynamic effect (with NIR irra-diation at 1-2W for 5-15 min). The temperature of the ICG-loaded hydrogels was also raised up-on the NIR irradiation to eradicate tumor cells photothermally. In vitro cytocompatibility as-sessments revealed the non-toxic nature of CMC-Nb and Alg-mTz towards HEK-293 cells. Fur-thermore, the ICG-loaded hydrogels effectively inhibited the metabolic activity of Hela cells following NIR exposure. This innovative hydrogel system holds promise for applications in combined PTT and PDT.

Rechargeable aqueous Zn-ion batteries (ZIBs) have attracted considerable attention owing to their high theoretical capacity of 820 mA h g‒1, low cost and intrinsic safety. However, the electrolyte leakage and the instability issues of Zn negative electrodes originating from side reactions between the aqueous electrolyte and Zn negative electrode, not only restricts the battery stability but also results in short-circuit of aqueous ZIBs. Herein we report a flexible and stable N-isopropylacrylamide/sodium alginate (N-SA) gel electrolyte, which possesses high mechanical strength and high ionic conductivity of 2.96×10‒2 S cm‒1, and enables the Zn metal negative electrode and MnO2 positive electrode to reversibly and stably cycle. Compared to the liquid electrolyte, the N-SA hydrogel electrolyte can effectively form a uniform Zn deposition and suppress the generation of irreversible by-products. The assemble symmetric Zn/Zn cells at a current density of 1 mA cm‒2 shows a stable voltage profile, which maintains a low level of about 100 mV over 2600 h without an obvious short circuit or any overpotential increasing. Specially, the assembled Zn/N-SA/MnO2 batteries can deliver a high specific capacity of 182 mAh g‒1 and maintain 98% capacity retention after 650 cycles at 0.5 A g‒1. This work provides a facile method to fabricate high-performance SA-based hydrogel electrolytes that illustrates their potential for flexible batteries for wearable electronics.

The current pandemic is urgently demanding to discover alternative materials capable of inactivate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes the coronavirus 2019 (COVID-19) disease. Calcium alginate is a crosslinked hydrophilic biopolymer with an immense range of biomedical applications due to its excellent chemical, physical and biological properties. In this study, the cytotoxicity and antiviral activity of calcium alginate in the form of films were studied. The results showed that these films are biocompatible in human keratinocytes and are capable of inactivating enveloped viruses such as bacteriophage phi 6 with a 1.43-log reduction (94.92% viral inactivation) and SARS-CoV-2 Delta variant with a 1.64-log reduction (96.94% viral inactivation) in virus titers. The antiviral activity of these calcium alginate films can be attributed to its negative charge density that may bind to viral envelopes inactivating membrane receptors.

Hazardous chemicals like toxic organic dyes are very harmful to the environment and their removal is quite challenging. Therefore there is a necessity to develop techniques, which are environment friendly, cost-effective and easily available in nature for water purification and re-mediation. The present research work is focused on the development` and characterization of the ecofriendly polyvinyl alcohol (PVA) and alginate (Alg) hydrogel beads incorporating natural bentonite (Bent) clay as beneficial adsorbents for removal of toxic methylene blue (MB) from industrial water. PVA−Alg/Bent nanocomposite hydrogel beads with different Bent content (0, 10, 20, and 30 wt%) were synthesized via external ionic gelation method. The designed porous and steady structure beads were characterized by the use of Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). The performance of the beads as MB adsorbents was investigated by treating batch aqueous solutions. The experimental results indicated that the incorporation of Bent (30 w%) in the nanocomposite formulation sustained porous structure, preserved water uptake, and increased MB removal effi-ciency by 230 % compared to empty beads. Designed beads possessed higher affinity to MB at high pH 8, 30 °C, and fitted well to pseudo-second-order kinetic model a high correlation coefficient. Moreover, designed beads had a good stability and reusability as they exhibited excellent removal efficiency (90%) after six consecutive adsorption-desorption cycles. Adsorption process was found be combination of both monolayer adsorption on homogeneous surface and multilayer adsorption on heterogeneous surface. The maximum adsorption capacity of the designed beads system as calculated by Langmuir isotherm was found to be 51.34 mg/g, which is in good agreement with the reported clay-related adsorbents. The designed PVA−Alg/Bent nanocomposite hydrogel beads demonstrated good adsorbent properties and could be potentially used for MB removal from polluted water.

Among the different ways to reduce the secondary effects of antineoplastic drugs in cancer treatment, the use of nanoparticles has demonstrated good results due to the protection of the drug and the possibility of releasing compounds to a specific therapeutic target. The α-isoform of folate receptor (FR) is overexpressed on a significant number of human cancers; therefore, folate-targeted crosslinked nanoparticles based on BSA and alginate mixtures and loaded with paclitaxel (PTX) have been prepared to maximizing the proven antineoplastic activity of the drug against solid tumors. Nanometric-range sized particles (169 ± 28nm - 296 ± 57nm), with negative Z-potential values (between -0.12 ± 0.04 and -94.1± 0.4), were synthesized. The loaded PTX (2.63±0.19 - 3.56 ±0.13 µg PTX/mg Np) was sustainably released along 23 and 27h. Three cell lines (MCF-7, MDA-MB-231 and HeLa) were selected to test the efficacy of the folate-targeted PTX-loaded BSA/ALG nanocarriers. The presence of FR on cell membrane led to a significant larger uptake of BSA/ALG-Fol nanoparticles regarding to the equivalent nanoparticles without folic acid on its surface. The cell viability results demonstrated a cytocompatibility of unloaded nanoparticle-Fol and a gradual decrease in cell viability after treatment with PTX-loaded nanoparticles-Fol due to the sustainable PTX release.

Curcumin is a promising anti-cancer drug but its applications in cancer therapy are limited due to its poor solubility, short half-life and low bioavailability. In this study, curcumin loaded magnetic alginate / chitosan nanoparticles were fabricated to improve the bioavailability, uptake efficiency and cytotoxicity of curcumin to MDA-MB-231 breast cancer cells. Alginate and chitosan were deposited on Fe3O4 magnetic nanoparticles based on their electrostatic properties. The sizes of the nanoparticles (120-200 nm) were within the optimum range for drug delivery. Sustained curcumin release was obtained use the nanoparticles with the ability to control the curcumin release rate by altering the number of chitosan and alginate layers. Confocal fluorescence microscopy results showed that targeted delivery of curcumin with the aid of magnetic field were achieved. The FACS assay indicated that MDA-MB-231 cells treated with curcumin loaded nanoparticles had a 3-6 folds uptake efficiency to those treated with free curcumin. MTT assay indicated that the curcumin loaded nanoparticles exhibited significantly higher cytotoxicity toward MDA-MB-231 cells than toward HDF cells. The sustained release profiles, enhanced uptake efficiency and cytotoxicity to cancer cells as well as the targeting potential make MACPs a promising candidate for cancer therapy.

In this investigation dyeing of alginate fiber was carried out after cationic treatment of EPTAC (2, 3-Epoxypropyl Trimethyl Ammonium Chloride). Optimum dyeing process and parameter show good dyeing performance when alginate fiber dyed with rhubarb dye. In addition to cationic treatment is taken into account for alginate fiber to improve fastness, color strength, breaking strength. Later in dyeing for fixation ferrous sulfate, copper sulphate was considered as mordents. Moreover using pre-mordanting methods conveyed the dyeing of alginate fiber with the stave of metallic mordant and without metallic salt mordents. The evaluation of each color dyed material was done through following two terms for instance CIELAB (L*, a*, and b*) and K/S values. According to AATCC test methods color fastness to washing of the dyed fiber was determined whereas according to the ASTM D3822M standard the breaking strength of alginate fiber was estimated and tested. When dyeing was carried out on alginate fiber through considering optimum parameter like 80◦C for 90 min, M: L 1:40 and at pH 7 which showed optimum results. In addition to mostly very good wash fastness was obtained while there was no fading of the color, whereas the moderate level of color fastness to crocking was achieved. Later after dyeing the evaluations of SEM of the cationized alginate fiber and FTIR of powder from the rhubarb dye were observed. The results suggested that the surface of cationized alginate fiber was smoother than the raw alginate fiber.

The application of chitosan and alginate coatings for Ready-to-Eat (RTE) baked fish product were studied. An experimental design was used to investigate the effect of coating polysaccharide concentration and glycerol addition on the safety (microbial growth), and quality (water loss and lipid oxidation) of RTE seafood product under optimal, and abused storage conditions. The results showed that a chitosan coating with 1% (w/v) chitosan in 1% (v/v) acetic acid, and 15% (w/w chitosan) glycerol, or 1% (w/v) alginate coating with no glycerol, and no crosslinking showed the best performance in controlling the tested safety and quality parameters. Desirability method was used to identify the shelf life of chitosan, alginate and double coated RTE products. Whereby, chitosan coated samples showed the best performance with a third fold shelf life extension compared to uncoated products.

The modification of cellulose woven fabrics and viscose nonwovens was carried out with the aim of preparing sustainable coatings from biodegradable natural polymers. The modification of fabrics with biodegradable natural polymers represents an ecological alternative to other textile modifications such as the sol-gel process. Coatings were prepared from erythritol, gelatin and collagen in various formulations with the addition of propolis and alginate fibers and a natural plasticizer (glycerin). The morphology of the materials was determined before and after modification with Dino-lite, the pH value, the drop test method, the angle recovery angle, the thickness and the mass per unit area. The modifications have no significant effect on the thickness and mass per unit area, in a larger proportion they show hydrophilic properties, which favours the application for medical purposes - for example the absorption of exudates, wound dressings etc. Due to the neutral and slightly alkaline pH value of the modified samples, they are suitable for external application on the skin. The recovery angle of the modified samples proves that the samples do not tend to crease and that they retain their elasticity after modification and have a pleasant textile feel (fabric hand).

Abstract: To reduce the indiscriminate use of pesticides and extend the postharvest shelf life of peach fruit (cv. Baihua) from southeast China, microbial antagonism of indigenous yeasts was mainly studied and applied in construction of composite film. After isolation, purification, cultivation and identification, a total of 14 yeast strains from 9 genera were screened out from the surface of peaches. By experimental analysis of in vitro inhibition zone and in vivo colonizing capacity, Candida oleophila sp-ELPY12B and Cryptococcus laurentii sp-ELPY15A, which have conservative structure of D1/D2 domain sequences and were considered as new species by phylogenetic analysis, were finally chosen as fungicides against the major pathogens. In combination of Na-alginate film (0.4 % glycerin as plasticizer and 0.1 % Tween-80 as emulsifier), the preservative effects of composite-treated groups (1 × 108 CFU mL−1 of Candida oleophila sp-ELPY12B and Cryptococcus laurentii sp-ELPY15A) showed best antifungal effects, which significantly delayed the postharvest preservation period about 6 - 7 d under ambient temperature of 25 ± 3°C and relative humidity of 50 - 70%.

The aim of this study was to determine the microbial stability, challenge to L. monocytogenes, and some physicochemical properties of turkey breast meat by alginate-based coating enriched with postbiotics (8% concentration, CFS) of Bifidobacterium bifidum DSM 20456 and Bifidobacterium bifidum BB12 strains. For this purpose, firstly, some antimicrobial and total phenolic matter, flavonoid, and DPPH activity values of postbiotics were determined. In addition, FTIR analysis was performed to see the intermolecular interactions of the biological coating agent. As a result of the study, alginate solution with postbiotic showed significant differences in pH, a*, b*, yeast-mold values of turkey meat during storage (7 days), while L* value, total aerobic mesophilic bacteria count (TMAP), psychrotrophic bacteria (PAB), lactic acid bacteria (LAB) and Listeria monocytogenes count were not effective (p>0.05).

In this study, sodium alginate (SA) was oxidized with potassium periodate to produce an alginate-based tanning agent. Using OSA as a biodegradable tanning agent and a nano-hydroxyapatite (nano-HAp) low concentration suspension to give flame retardancy to leather, eco-design concepts were applied to establish a chrome-, aldehyde-, and phenol-free tanning process. Micro-DSC, 1H NMR, attenuated total reflection mode Fourier transform infrared spectroscopy (FTIR-ATR), and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) were used to investigate the complex matrix collagen-OSA-nano-HAp. Micro-differential scanning calorimetry (micro-DSC) was used to assess OSA's ability to interact with collagen and stabilize the collagen-OSA matrix, while 1H unilateral nuclear magnetic resonance (NMR) was used to investigate the aqueous environment and limitations around collagen molecules caused by their association with OSA and nano-HAp. Industrial standard tests were used to assess mechanical properties and fire resistance of the new leather prototype. The findings reported here indicate that both OSA and nano-HAp are suitable alternatives for cleaner tanning technologies and more sustainable leather.

Alginate-gelatin hydrogels are extensively used in bioengineering. However, despite different formulations being utilized for growing different cell types in vitro, their pH and its effect, together with the crosslinking ions, of those formulations are still infrequently assessed. In this work we studied how these elements can affect hydrogel stability and printability and influence U2OS and NIH/3T3 cell viability and metabolism on the resulting 3D prints. In this context, 6% alginate + 2% gelatin hydrogels were prepared with 0.1 M MES buffer with pH 5.5, 6.5, 7.0 or 8.0, printed by extrusion-based 3D printing, and crosslinked immediately after printing with either CaCl2 or BaCl2. Our results showed that both the buffer pH and the crosslinking ion (Ca2+ or Ba2+) influence the swelling and degradation rates of the prints. Moreover, the buffer pH influenced the printability of the hydrogel in air, but when printed directly in a fluid-phase CaCl2 or BaCl2 crosslinking bath. In addition, both U2OS and NIH/3T3 cells showed greater cell metabolic activity on one-layer prints crosslinked with Ca2+. Besides, Ba2+ increased cell death of NIH/3T3 cells while had no effect on the U2OS cell viability. The pH of the buffer also caused an important impact on the cell behaviour. U2OS cells showed a 2.25-fold cell metabolism increase on one-layer prints prepared at pH 8.0 in comparison to those prepared at pH 5.5. Whereas, NIH/3T3 cells showed greater metabolism on one-layer prints with pH 7.0. Finally, we observed a difference on cell arrangement of the U2OS cells growing on prints prepared from hydrogels with acidic buffer in comparison to cells growing on those prepared using neutral or basic buffer. These results show that both pH and crosslinking ion influence hydrogel strength and cell behaviour.

Hydrogels, soft materials with 3D polymer networks in aqueous solution, have been developed for engineering and bio-related fields. However, these conventional hydrogels are weak and brittle due to lack of energy dissipation mechanisms. Recently, dual-network hydrogels have been proposed, combining rigid and flexible networks and exhibiting high strength, stretchability, and toughness. This paper explores the rheological properties of dual-network hydrogels based on acrylamide and sodium alginate under large deformations. This dual network is a combination of a covalently crosslinked polyacrylamide network and a supramolecular crosslinked sodium alginate network at the presence of divalent calcium cations. Small and large amplitude oscillatory shear methods with Fourier transform rheology, stress decomposition method, and Chebyshev polynomial analysis of large amplitude oscillatory shear (LAOS) data were employed to evaluate non-linearity limit, toughness, and network rigidity. The concentration of calcium ions affects (concentrations 0-80 mg/ml) the nonlinear transition and limit points, and all gel samples exhibit strain hardening, shear thickening, and shear densification.

In cystic fibrosis (CF), pulmonary infection with Pseudomonas aeruginosa is a cause of increased morbidity and mortality, especially in patients for whom infection becomes chronic and there is reliance on long-term suppressive therapies. Current antimicrobials, though varied mechanistically and by mode of delivery, are inadequate not only due to eradication failure in many cases, but also because they do not halt the progression of lung function decline over time. One of the reasons for this failure is thought to be the biofilm mode of growth of P. aeruginosa, wherein self-secreted exopolysaccharides (EPSs) provide physical protection against antibiotics and an array of niches with resulting metabolic and phenotypic heterogeneity. Targeting the three EPSs secreted by P. aeruginosa (alginate, Psl and Pel) is currently under investigation as a way of disrupting the biofilm extracellular matrix to potentiate the action of antibiotics. In this review, we look at each EPS as a potential therapeutic target for combatting pulmonary infection with P. aeruginosa in CF, with a particular focus on the current evidence for these emerging therapies and barriers to bringing these therapies into clinic.

The objective of this study was to assess the ability of producing laminated edible films manufactured using the following proteins; gelatin (G), whey protein isolate (WPI), and polysaccharide; sodium alginate (SA), and to evaluate their physical properties. Additionally, films’ preparation employing these ingredients was optimized through the addition of corn oil (O), Overall, 8-types of laminated films (G-SA, G-WPI, SA-WPI, SA-G-WPI, GO-SAO, GO-WPIO, SAO-WPIO, SAO-GO-WPIO were developed in this study. The properties of the prepared films were characterized through the measurement of; tensile strength (TS), elongation at break point (EB), puncture resistance (PR), tear strength (TT), water vapour permeability (WVP) and oxygen permeability (OP). The microstructure of cross-sections of laminated films was investigated by scanning electron microscopy (SEM). Mechanical properties of films were dramatically enhanced through the addition of film layers. GO-SAO laminate showed the best barrier properties to water vapour (22.6 ± 4.04 g mm/kPa d m2) and oxygen (18.2 ± 8.70 cm3 mm/kPa d m2). SAO-GO-WPIO laminate film was the strongest of all laminated films tested, having the highest TS of 55.77 MPa, PR of 41.36 N and TT of 27.32 N. SA-G-WPI film possessed the highest elasticity with an EB value of 17.4%.

Mastitis-causing bacteria can establish persistent infections in the mammary gland of commercially important dairy animals despite the presence of strong specific humoral and cellular immune mechanisms. The aim of this study was to encapsulate vitamin D3 by complex coacervation with sulfur-saturated bovine lactoferrin-alginate using microbial transglutaminase-catalyzed crosslinking and investigate the oral administration of encapsulated vitamin D3 in blood serum biomarkers of the immune response in late-lactating dairy goats. Dairy goats (n = 18) in late lactation were randomly assigned to three experimental groups (n = 6), after balancing weight. Dairy goats were orally administered with 0.35 mg vitamin D3/day in the unencapsulated form and 0.35 mg vitamin D3/day in the encapsulated powder form. Another group received the basal diet. The experimental period lasted 6 weeks. The blood serum concentrations of 25-hydroxyvitamin D3 [25-(OH)-D3], lactoferrin, immunoglobulin A (IgA), and interferon-gamma (INF-γ) were measured. The delivery of vitamin D3 to dairy goats resulted in a marked increase of 25-(OH)-D3 concentration in serum while the serum level of lactoferrin also increased. Alternatively, the serum levels of IgA and the immunomodulatory cytokine INF-γ were elevated following supplementation with the encapsulated vitamin D3. Overall, the capsules in the powder form used in this study kept vitamin D3 highly bioavailable.

A heterograft copolymer with an alginate backbone, hetero-grafted by polymer pendant chains displaying different Lower Critical Solution Temperatures (LCSTs), combined with a pH-responsive Poly(2-vinyl pyridine)-b-poly(ethylene oxide) (P2VP-b-PEO) diblock copolymer forming micellar nanoparticles, was investigated in aqueous media at various pH. Due to its thermoresponsive side chains, the copolymer forms hydrogels with thermo–induced sol–gel transition, above a critical temperature, Tgel (thermo–thickening). However, by lowering pH of the medium in acidic regime, a remarkable increase of the elasticity of the formulation was observed. This effect was more pronounced in low temperatures (below Tgel) suggesting secondary physical crosslinking, which induces significant changes in the hydrogel thermoresponsiveness, transforming the sol–gel transition to soft gel–strong gel. Moreover, the onset of thermothickening shifted to lower temperatures followed by broadening of the transition zone, implying intermolecular interactions between the uncharged alginate backbone with the PNIPAM side chains, likely through H–bonding. The shear–thinning behavior of the soft gel in low temperatures provides injectability, which allows 3D–printing potential applications. Furthermore, the heterograft copolymer/nanoparticles composite hydrogel, encapsulating a model hydrophobic drug in the hydrophobic cores of the nanoparticles, was evaluated as pH-responsive drug delivery system. The presented tunable drug delivery system might be useful for biomedical potential applications.

The necessity to reduce the effect of the greenhouse phenomenon imposed the turn of the food packaging technology to the use of biobased raw materials decreasing the carbon dioxide fingerprint. In this direction alginates derived from brown algae species are of the most promising biobased biopolymers, used for development of edible active coatings, capable to protect food from oxidation/bacterial spoilage. In this study sodium alginate, which was plasticized with glycerol and mixed with a biobased thymol/natural halloysite nanohybrid, was used to develop novel edible active coatings. Active nanocomposite coatings developed by mixing of pure halloysite with sodium alginate/glycerol matrix were produced for comparison purposes. X-Ray and Fourier Transform Infrared Spectroscopy indicated higher compatibility of thymol/halloysite nanohybrid with sodium alginate/glycerol matrix compared to the relevant of pure halloysite. This increased compatibility led to higher tensile properties, water/oxygen barrier properties, and total antioxidant activity. All coating samples were applied as edible active coatings for “tsalafouti” spreadable soft cheese, exhibited a reduction of mesophilic microbial population of more than one log10(cfu/g) unit comparing with uncoated cheese. Moreover, the reduction of mesophilic microbial population was increased by increasing halloysite and thymol content which indicates the sodium alginate/glycerol/thymol/halloysite as promising edible active coatings for “tsalafouti”.

The present article describes a one-pot and cascade mode process using biocompatible/biodegradable reagents, for directly and simply obtaining surfactant compositions of mixtures of D-mannuronic acid and L-guluronic acid directly from oligoalginates or semi-refined alginates (mixtures of alginate, cellulose, hemicellulose, laminaran and fucan). Simple treatments of partial purification of the reaction crudes (elimination of the salts and/or the residual fatty alcohols) or isolation of the surfactant compositions result in derived compounds and in compositions having performance levels appropriate to applications in detergency. In addition, the challenging extension of this cascading one-pot synthesis technology to crude milled brown seaweeds was successfully carried out to provide promising surface-active compositions made up of alkyl uronate and alkyl glycoside monosaccharides.