Selective adsorption and separation of methylene blue by facily preparable xanthan gum/amantadine composites

In this work, xanthan gum-based composites were successfully graft-modified by amantadine (XG-Fe³⁺/AM) with higher adsorption capacity and selectivity on recycling cationic dye (methylene blue, MB) from aqueous solution. The adsorption equilibrium of MB could be achieved approximately within 5 min when the initial concentration was 100 mg/L, and the maximum adsorption capacity was up to 565 mg/g. After 5 desorption-regeneration cycles, the removal rate of XG-Fe³⁺/AM for MB could still be as high as 95 % with slight decrement. Additionally, the effects of pH, contact time, temperature and initial dye concentration on the adsorption performance of MB were systematically examined. Furthermore, the adsorbent was characterized by FT-IR, BET and XPS analysis. In mixed anionic and cationic dyes, the adsorption selectivity of XG-Fe³⁺/AM on MB in the mixture of MB and methyl orange (MO) reached up to 99.69 %. Molecular dynamics simulation revealed that the trend of adsorption energy for dyes was in good agreement of the experimental order of adsorption capacities and molecular sizes among seven anionic and cationic dyes based on molecular matching effect and electrostatic interaction. Therefore, XG-Fe³⁺/AM is an eco-friendly, facile-synthesis and high-selectivity adsorbent, which remove cationic dyes in multi-component systems through electrostatic interaction and molecular matching effect.

Preparation and emulsification properties of cationic starch-xanthan gum composite nanoparticles

In this work, nanoparticles were prepared by the composite of cationic starch (CS) and xanthan gum (XG) through gelatinization and alcohol precipitation for the first time. Physicochemical properties, micromorphology, and emulsification properties of CS/XG nanoparticles were measured. SEM showed that after compositing with XG, the diameter size of the CS/XG nanoparticles was increased from about 50 nm to 150-300 nm. FT-IR, XRD and ¹³C CP/MAS NMR confirmed that XG was successfully complexed with CS. Besides, the visual observation indicated emulsions stabilized by CS/XG nanoparticles had excellent storage and thermal properties. Additionally, the rheological and stability results of emulsions show that pH and NaCl had effects on the rheological and stability properties of emulsions, which means that the prepared emulsions had environmental responsiveness. Thus, this work provides an efficient method to prepare CS and GX composite nanoparticles with efficient emulsifying properties.

Graphite nanopowder incorporated xanthan gum scaffold for effective bone tissue regeneration purposes with improved biomineralization

In the current work, biomaterial composed of Xanthan gum and Diethylene glycol dimethacrylate with impregnation of graphite nanopowder filler in their matrices was fabricated successfully for their potential usage in the engineering of bone defects. Various physicochemical properties associated with the biomaterial were characterized using FTIR, XRD, TGA, SEM etc. The biomaterial rheological studies imparted the better notable properties associated with the inclusion of graphite nanopowder. The biomaterial synthesized exhibited a controlled drug release. Adhesion and proliferation of different secondary cell lines do not generate ROS on the current biomaterial and thus show its biocompatibility and non-toxic nature. The synthesized biomaterial's osteogenic potential on SaOS-2 cells was supported by increased ALP activity, enhanced differentiation and biomineralization under osteoinductive circumstances. The current biomaterial demonstrates that in addition to the drug-delivery applications, it can also be a cost-effective substrate for cellular activities and has all the necessary properties to be considered as a promising alternative material suitable for repairing and restoring bone tissues. We propose that this biomaterial may have commercial importance in the biomedical field.

Rheological Issues on Oropharyngeal Dysphagia

There is an increasing proof of the relevance of rheology on the design of fluids for the diagnosis and management of dysphagia. In this sense, different authors have reported clinical evidence that support the conclusion that an increase in bolus viscosity reduces the risks of airway penetration during swallowing. However, this clinical evidence has not been associated yet to the definition of objective viscosity levels that may help to predict a safe swallowing process. In addition, more recent reports highlight the potential contribution of bolus extensional viscosity, as elongational flows also develops during the swallowing process. Based on this background, the aim of this review paper is to introduce the lecturer (experts in Dysphagia) into the relevance of Rheology for the diagnosis and management of oropharyngeal dysphagia (OD). In this sense, this paper starts with the definition of some basic concepts on Rheology, complemented by a more extended vision on the concepts of shear viscosity and elongational viscosity. This is followed by a short overview of shear and elongational rheometrical techniques relevant for the characterization of dysphagia-oriented fluids, and, finally, an in-depth analysis of the current knowledge concerning the role of shear and elongational viscosities in the diagnosis and management of OD (shear and elongational behaviors of different categories of dysphagia-oriented products and contrast fluids for dysphagia assessment, as well as the relevance of saliva influence on bolus rheological behavior during the swallowing process).

Pickering emulsion: A multi-scale stabilization mechanism based on modified lotus root starch/xanthan gum nanoparticles

New Pickering emulsion stabilizer LS/XG-NPs (Lotus root starch/xanthan gum nanoparticles) was prepared via autoclaving-cooling method followed by combination with XG. The LS/XG-NPs showed uniform and stable particles with particle size <500 nm, PDI <30, and zeta potential 30-40. The autoclaving-cooling treatment completely changed the crystalline form (from A-type to B-type) and structure of starch; hydrogen bonding and electrostatic interactions were proved to be existed between starch and XG in LS/XG-NPs. The addition of XG increased the contact angle of LS/XG-NPs from 58.79° to 85.42°. In the prepared Pickering emulsion, the LS/XG-NPs adsorbed well on the oil droplets surface, forming a three-dimensional gel network with evenly distributed oil droplets. The Pickering emulsion prepared with LS/XG-NPs showed excellent storage stability and auto-oxidation resistance; the EPA + DHA content in the emulsion remained at 92.46 % after 5 d of storage. The results of this study suggest that LS/XG-NPs have the potential to be food-grade Pickering emulsifiers that not only stabilize emulsions but also prevent emulsion oils from oxidizing.

Dual-network polyvinyl alcohol/polyacrylamide/xanthan gum ionic conductive hydrogels for flexible electronic devices

Ionic conductive hydrogels (ICHs) have received widespread attention as an ideal candidate for flexible electronic devices. However, conventional ICHs failed in widespread applications due to their inability to simultaneously possess high toughness, high ionic conductivity, and anti-freezing properties. Here, polyvinyl alcohol (PVA) and polyacrylamide (PAAm) were first dissolved in the zinc chloride solution, in which zinc ions (Zn²⁺) act as ionic cross-linkers and conducting ions, followed by the introduction of xanthan gum (XG) with a unique structure of trisaccharide side chains into the PVA/PAAm semi-interpenetrating network to prepare a dual-network ICHs (refers as PPXZ). Enabled by the synergistic effect of intermolecular chemical covalent cross-linking and physical cross-linking, PPXZ hydrogels exhibit significantly improved mechanical properties without sacrificing electrical conductivity. Furthermore, PPXZ hydrogels are successfully applied to flexible electronic devices, such as strain sensors and zinc ion hybrid supercapacitors, exhibiting satisfactory sensing sensitivity and cycling stability at a wide temperature range, respectively. Even at a high current density (10 A g^-1), the capacity of the supercapacitor retains 88.24 % after 10,000 cycles. This strategy provides new insight for ICHs in wide temperature-applied flexible electronic devices.

Dual thermal stabilizing effects of xanthan gums via glycosylation and hydrogen bonding and in vivo human bioavailability of desmopressin in orodispersible film

Desmopressin acetate (DDAVP), a nonapeptide drug, is easily destroyed by heat in the manufacturing process of orodispersible film (ODF). A new challenging study was conducted to improve thermal stability through glycosylation and hydrogen bonding using carbohydrate gums (agar, arabic gum, carrageenan, xanthan gum) using the solvent casting method. Among gum types, xanthan gum strongly showed dual stabilizing effects of DDAVP via covalent glycosylation and hydrogen bonding, minimizing total impurities and optimizing physicochemical properties of ODF under accelerated conditions for six months. The optimized ODF formulation (O-DDAVP ODF) at a DDAVP and xanthan gum ratio of 1:1.5 had a pharmaceutically equivalent dissolution profile as compared with a commercial 0.2 mg commercial Minirin® tablet in four different media: pH 1.2, pH 4.0, and pH 6.8 buffers and deionized water. Furthermore, O-DDAVP ODF showed in vivo bioequivalence to Minirin® tablets in healthy human volunteers. Glycosylation-oriented stabilization of peptide drug using pharmaceutically active excipients against thermal denaturation could be challenged to design patient-friendly ODF.

Design and in vitro effectiveness evaluation of Echium amoenum extract loaded in bioadhesive phospholipid vesicles tailored for mucosal delivery

The Echium amoenum Fisch. and C.A. Mey. (E. amoenum) is an herb native from Iranian shrub, and its blue-violet flowers are traditionally used as medical plants. In the present study, an antioxidant phytocomplex was extracted from the flowers of E. amoenum by ultrasounds-assisted hydroalcoholic maceration. The main components, contained in the extract, have been detected using HPLC-DAD, and rosmarinic acid was found to be the most abundant. The antioxidant power of the extract along with the phenolic content were measured using colorimetric assays. The extract was loaded in liposomes, which were enriched adding different bioadhesive polymers (i.e., mucin, xanthan gum and carboxymethyl cellulose sodium salt) individually or in combination. The main physico-chemical properties (i.e. size, size distribution, surface charge) of the prepared vesicles were measured as well as their stability on storage. The viscosity of dispersion and the ability of vesicles to interact with mucus were evaluated measuring their stability in a mucin dispersion and mobility in a mucin film. The biocompatibility and the ability of the formulations to protect keratinocytes from damages caused by hydrogen peroxide and to promote the cell migration were measured in vitro.

Adsorption of Pb (II) and Cu (II) by magnetic beads loaded with xanthan gum

Green and environmentally friendly and efficient separation adsorbents have attracted much attention in the treatment of heavy metal ions wastewater. In this study, xanthan gum (XG) was supported by fly ash magnetic beads (FAMB) to prepare adsorbent XG@FAMB. The effects of XG@FAMB dosage, pH value of the solution, adsorption time, and initial Pb (II) and Cu (II) concentration on its adsorption performance for Pb (II) and Cu (II) were investigated. The results show that under the conditions of pH 6, dosage of XG@FAMB 4.0 g/L, adsorption time 120 min, and initial concentration 60 mg/L, the maximum adsorption capacity of XG@FAMB for Pb (II) and Cu (II) was 14.93 mg/g and 14.88 mg/g, respectively. The adsorption process of Pb (II) and Cu (II) by XG@FAMB could be better described by the quasi-second-order kinetic model and Langmuir isothermal adsorption model, that is, the adsorption process is monolayer adsorption controlled by chemical action. The adsorption mechanism is that Pb (II) and Cu (II) coordinate with oxygen-containing functional groups hydroxyl and carboxyl on XG@FAMB surface, accompanied by electrostatic adsorption. XG@FAMB has the advantages of environmental protection of XG and easy solid-liquid separation of FAMB, and has a good removal effect on Pb (II) and Cu (II).

Development and systematic characterization of GelMA/alginate/PEGDMA/xanthan gum hydrogel bioink system for extrusion bioprinting

Gelatin methacryloyl (GelMA)/alginate-based hydrogels have shown great promise in bioprinting, but their printability is limited at room temperature. In this paper, we present our development of a room temperature printable hydrogel bioink by introducing polyethylene glycol dimethacrylate (PEGDMA) and xanthan gum into the GelMA/alginate system. The inclusion of PEGDMA facilitates tuning of the hydrogel's mechanical property, while xanthan gum improves the viscosity of the hydrogel system and allows easy extrusion at room temperature. To fine-tune the mechanical and degradation properties, methacrylated xanthan gum was synthesized and chemically crosslinked to the system. We systematically characterized this hydrogel with attention to printability, strut size, mechanical property, degradation and cytocompatibility, and achieved a broad range of compression modulus (∼10-100 kPa) and degradation profile (100% degradation by 24 h-40% by 2 weeks). Moreover, xanthan gum demonstrated solubility in ionic solutions such as cell culture medium, which is essential for biocompatibility. Live/dead staining showed that cell viability in the printed hydrogels was over 90% for 7 days. Metabolic activity analysis demonstrated excellent cell proliferation and survival within 4 weeks of incubation. In summary, the newly developed hydrogel system has demonstrated distinct features including extrusion printability, widely tunable mechanical property and degradation, ionic solubility, and cytocompatibility. It offers great flexibility in bioprinting and tissue engineering.

Biopolymer templated strategized greener protocols for fabrication of ZnO nanostructures and their application in photocatalytic technology for phasing out priority pollutants

Zinc oxide (ZnO) nanostructures have been successfully synthesized via template-assisted and template-free route using three different synthetic methods, i.e., sonochemical, mechanochemical, and hydrothermal. Biopolymer xanthan gum (XG) served as sacrificial template for ZnO synthesis as provided the surface for the growth of nanostructures in a controlled manner. The employment of multifarious synthetic techniques resulted in fabrication of ZnO nanoparticles with diverse morphologies such as needle shaped, hexagonal, and spherical particles. Further, the template-assisted protocols generated thermally stable highly crystalline nanostructures along with high surface area, larger pore size, and low band gap energies in contrast to template-free protocol. The structural and other physicochemical studies were manifested by XRD, N₂ adsorption desorption, FESEM, TGA, and UV-Vis spectral analysis. The template-assisted ZnO nanostructures were explored as a potential photocatalyst for the catalytic degradation of emerging pollutants, i.e., triclosan (TCS) and imidacloprid (IMD) under the exposure of UV light. The products formed during the photocatalytic reaction were monitored by UV-Vis spectroscopy and HPLC. The results obtained revealed the high catalytic efficiency of ZnO synthesized via template-assisted sonochemical method for TCS (99.60%) and IMD (96.09%) which is attributed to the high surface area and lower band gap energy of the catalyst. The high catalytic potential of the sonochemically synthesized ZnO also substantiated from the kinetic data as high-rate constant was obtained. Thus, the template-assisted protocols developed led to preparation of nanostructures having tailored properties for efficient photocatalysis and can rapidly degrade selected emerging contaminants such as personal care products and organophosphate pesticides. Hence, environment-friendly synthesized photocatalyst can be appropriately employed to wastewater treatment contaminated with emerging pollutants.

Physical stability, microstructure and interfacial properties of solid-oil-in-water (S/O/W) emulsions stabilized by sodium caseinate/xanthan gum complexes

Calcium carbonate (CaCO₃) has poor suspension stability, which severely limits its application in food processing and products. In this study, sodium caseinate (NaCas) and sodium caseinate (NaCas)-xanthan gum (XG) mixtures were compared for the stable preparation of solid/oil/water (S/O/W) emulsions for the delivery of calcium carbonate (CaCO₃) to solve the problem of poor suspension stability. The physical stability, particle size distribution, and microstructure of S/O/W emulsions were investigated to prove the successful construction of the system. The dynamic surface pressure and surface swelling properties of 2.0 wt% NaCas with different concentrations of XG were investigated to clarify the effect of interfacial properties of NaCas-XG mixtures on the emulsion stability of S/O/W emulsions. The results showed that the addition of XG resulted in enhanced physical stability, reduced particle size distribution, and enhanced encapsulation effect of the emulsion, forming a more three-dimensional core-shell structure via dendritic links. XG had a significant effect on the dynamic properties of the NaCas adsorption membrane: NaCas interacted with XG and the diffusion (k_diff) of NaCas to the interface decreased in short adsorption time, thus limiting the protein adsorption effectiveness; the presence of XG reduced the penetration (k_P) and rearrangement (k_R) rates at the interface during long adsorption times. Meanwhile, the NaCas-XG mixture has a high swelling elasticity. The results of this study can be used to improve the quality of related emulsion products or to prepare delivery systems for bioactive compounds.

Structure-property relationship in the evaluation of xanthan gum functionality for oral suspensions and tablets

The functional properties of xanthan gum (XG) in pharmaceutical preparations depend on its rheological properties, which inevitably rely on its molecular structure. Hence, this work investigated the relationship between the molecular structure of XG and its rheological properties and functional characteristics, and revealed the structural factors influencing the XG functionalities in oral suspensions and matrix tablets. Primarily, the molecular structures of four commercial XG products were characterized by infrared spectroscopy, differential scanning calorimetry and measuring the monosaccharide composition, average molecular weight, and pyruvate and acetyl contents. Furthermore, the flow behavior and viscoelasticity of XG solutions, the viscoelasticity of XG hydrogels, and XG combinations (XGC, aqueous solution containing XG, liquid glucose, and glycerin) were investigated. Finally, the dissolution time of XGC and the swelling and erosion properties of the XG matrix were studied to evaluate XG functionality in oral suspensions and matrix tablets, respectively. Results showed that the polydispersity of molecular weight and the pyruvate content affected the functionality and performance of XG in suspension and tablet forms. The higher polydispersity and pyruvate content of XG improved the hydrogel strength, which led to a longer dissolution time of XGC and a higher swelling extent of the XG matrix but a slower erosion rate.

Synergistic studies of Cassia tora gum with xanthan and guar gum: Carboxymethyl synthesis of cassia gum-xanthan synergistic blend and characterization

The present study describes the study of synergistic behavior of the Cassia tora (CTG) gum with xanthan gum (XG) and comparison with CTG and guar gum (GG) at varying temperatures. A carboxymethyl derivative of CTG: XG blend, having synergistic activity was synthesized and the reaction conditions were optimized using Taguchi's L'9 statistical design. The effect of solvent medium on the degree of substitution (DS) and the gelling property was also studied. The results reveal that synergistic interaction was found in the CTG: XG mixture whereas CTG: GG blend did not show synergistic behavior. The CTG: XG blend shows a highly viscous solution having 8371.9 cps viscosity at ambient temperature and gel is obtained by heating the blending solution and thereafter lowering the temperature. In continuum, an optimized carboxymethyl derivative (DS 0.16) also exhibits gelling properties. The carboxymethyl derivative was characterized by ¹H NMR, FTIR spectroscopy and FESEM analysis. The synergistic action of gums may be utilized in food, cosmetics and pharmaceutical applications.

Static stability of partially crystalline emulsions: Impacts of carrageenan and its blends with xanthan gum and/or guar gum

In the present study, four different combinations of gums, including carrageenan (CG), its binary blends with xanthan gum (XG) or guar gum (GG) in equal ratios, and its ternary blends with XG and GG in three equal ratios, were involved into making partially crystalline emulsions (PCEs), respectively. The freshly prepared emulsions were systematically characterized by rheological property, particle size distribution, microscopic morphology, interfacial property, and intermolecular interactions, and their emulsion stabilities were further evaluated using multiple light scattering technique and storage test. All PCEs stabilized by gum blends (CG + XG, CG + GG, and CG + XG + GG) obtained decreased apparent viscosities at 0.01 s^-1 (10.12-25.32 Pa·s), particle sizes (3.12-4.06 μm), as well as interfacial protein concentrations (22.60-27.01 mg/m²), which were much lower than those with single CG (35.98 Pa·s, 6.72 μm, and 47.74 mg/m², respectively). The microscopic morphology showed that blending CG with XG and/or GG contributed to formation of firmer three-dimensional matrix, thereby preventing the aggregation of fat droplets. Inclusion of XG and/or GG also significantly reduced contribution of hydrophobic interactions from 0.72 to 0.24-0.44 mg/mL. Both multiple light scattering and storage test revealed that emulsion instabilities were mainly manifested as a clarification at the bottom and an agglomeration at the top. PCE-CG + XG + GG exhibited superior stability with low creaming index (6.20 %) and viscosity (1180.0 mPa·s) after three months of storage. The research aims to evaluate the effects of CG and its blends with XG and GG on stability of PCEs, and the results potentially provide valuable information for manufacture of stable PCE foods.

Children With Celiac Disease Consume Specific Food Additives More Frequently Compared to Children Without Celiac Disease

BACKGROUND

Gluten-free foods often contain food additives to improve palatability, but the long-term effects on the human gastrointestinal tract are not well known.

AIMS

This study aimed to quantify frequency of food additive exposure in children with and without celiac disease (CD).

METHODS

Children with and without CD were enrolled and demographic data and three-day diet records were obtained. Foods were classified as gluten-free products (GFP) and "processed food", and were evaluated for presence of select food additives: polysorbate 80, carboxymethylcellulose, xanthan gum, guar gum, soy lecithin, titanium dioxide, carrageenan, maltodextrin, and aluminosilicates. The frequency of exposure was described.

RESULTS

Twenty-eight participants were included in final analysis. Children with CD had a higher number of daily exposures to xanthan gum (5.3 ± 3.1 vs 2.3 ± 2.4; p = 0.009), but similar exposures to the other additives. GFP contributed 29% of total calories in the GF diet. Both groups had similar intake of processed foods. Comparing GFP and gluten-containing processed foods, 68% vs. 25% contained at least one food additive of interest (p < 0.0001); in the celiac group, those with higher consumption of GFP tended to have a higher frequency of exposure to food additives (p = 0.09).

CONCLUSION

A gluten-free diet and consumption of GFP may contribute to differences in food additive intake; quantifying food additive exposures and their effect on humans requires further study.

Dataset on rheological measurements of xanthan gum aqueous dispersions containing sodium chloride and settling dynamics of spheres and disks in these dispersions

This paper presents a dataset collected in laboratory experiments on the settling of solid spheres and disks in shear-thinning and viscoelastic aqueous solutions of xanthan gum with sodium chloride addition. Two types of spheres with density of 1.41 g/cm³ varying in diameter (3.00 mm and 1.59 mm) and four types of disks with density of 1.43 g/cm³ and thickness of 0.3 mm varying in diameter (1.5 mm, 2.0 mm, 2.5 mm, and 3.0 mm) were considered. A single particle was settling in a column filled with a test solution which varied in salt content (from 0 M to 0.9 M), while xanthan gum content was constant (1 g/L). The total of elven solutions were tested. For each experimental set, a sequence of images with a falling particle was captured using a camera with macro lenses. Dataset includes position of particle in time and enables the evaluation of settling velocity. Rheological measurements were carried out for each test solution to assess flow properties and viscoelasticity. The following measurements were performed: shear dependent viscosity, shear stress amplitude sweeps, frequency sweeps, the dependence of the first normal stresses difference on shear strain at constant frequency (1 Hz). Datasets may be useful in various areas on fluid mechanics and rheology, e.g., in research on the impact of salinity on rheological properties of exopolymer solutions, to develop numerical models on solid particles settling in non-Newtonian fluids, and in studies on the impact of exopolymers and electrolytes dissolved in water on settling dynamics of solid particles.

Encapsulation of amino acids in water-in-oil-in-water emulsions stabilized by gum arabic and xanthan gum

In this study, several kinds of amino acids were successfully encapsulated in a W₁/O/W₂ emulsion produced using a two-step emulsification process. Polyglycerol polyricinoleate (PGPR) was used as a hydrophobic emulsifier in the oil phase, while gum arabic (GA) and xanthan gum (XA) were used as an emulsifier and stabilizer in the outer water (W₂) phase, respectively. The stability and encapsulation efficiency of the W₁/O/W₂ emulsions depended on the ratio of W₁/O emulsion to W₂ phase, as well as the concentration of GA and XA within the outer W₂ phase. A W₁/O/W₂ emulsion prepared using 2 % (w/w) GA and 0.3 % (w/w) XA in the W₂ phase exhibited good stability and a high encapsulation efficiency (>80 %) for several amino acids. As the hydrophobicity of amino acids and storage temperature increased, the leakage from the W₁ to W₂ phases increased, which can be attributed to increasing solubility in the oil phase. The encapsulation efficiency of lysine encapsulated in GA-XA-stabilized W₁/O/W₂ double emulsion was over 84 % after 28 days storage at 4 °C. These results indicate that double emulsions may be useful for the encapsulation of amino acids, which may be useful to protect them from their environment and mask bitter flavors.

Evaluation of chitosan/xanthan gum polyelectrolyte complexes potential for pH-dependent oral delivery of escin

Escin is an amphiphilic and weakly acidic drug that oral administration may lead to the irritation of gastric mucosa. The entrapment of escin into chitosan (CH)/xanthan gum (XG)-based polyelectrolyte complexes (PECs) can facilitate controlled drug release which may be beneficial for the reduction of its side effects. This study aimed to investigate the influence of escin content and drying method on the formation, physicochemical, and controlled, pH-dependent drug release properties of CH/XG-based PECs. Measurements of transmittance, conductivity, and rheological characterization confirmed the formation of CH/XG-based PECs with escin entrapped at escin-to-polymers mass ratios 1:1, 1:2, and 1:4. Ambient-dried PECs had higher yield, entrapment efficiency, and escin content in comparison with spray-dried ones. FT-IR spectra confirmed the interactions between CH, XG, and escin, which were stronger in ambient-dried PECs. PXRD and DSC analyses showed the amorphous escin character in all dry PECs, regardless of the drying method. The most promising controlled and pH-dependent in vitro escin release was from the ambient-dried PEC at the escin-to-polymers mass ratio of 1:1. For that reason and due to the highest yield and entrapment efficiency, this carrier has the potential to prevent the irritation of gastric mucosa after oral administration of escin.

Effects of guar gum or xanthan gum addition in conjunction with pasteurization on liquid egg white

In this study, effects of varying levels of xanthan or guar gum (XG/GG, 0.05%, 0.1%, 0.2%, 0.4% and 0.8%, w/v) on the spatial structure and functional properties of egg white (EW) proteins under different pasteurization conditions of the liquid egg was evaluated. Results showed that XG could bury the aromatic ring residues and reduce the hydrophobicity of protein in EW, whereas GG could only increase the hydrophobicity. With 0.8% GG addition and pasteurization under 60℃/3.5 min, the emulsifying stability of EW was improved by nearly 100%, while with 0.8% XG addition the gel structure of EWwould become porousandloosen under each pasteurization condition. The hardness of EW gels was decreased by 90% when the concentration of XG was 0.4% or 0.8%. According to the results, the concentration of gums and the pasteurization parameters should be considered together when adding gums into the liquid egg products for pasteurization simultaneously.

Multifunctional hydrogels for wound dressings using xanthan gum and polyacrylamide

Developing advanced dressings that integrate multiple functions is one of the major challenges in current clinical wound treatment. In this study, Xanthan gum (XG) and polyacrylamide (PAAm) materials were used to prepare hydrogel dressings by one-pot method. With the combination of the PAAm network and the XG network, the PAAm-XG hydrogels showed the tensile strength of 0.36 MPa and the stretchability as large as 2078 %. The prepared PAAm-XG hydrogels had excellent water uptake efficiency with the swelling ratio of 1200 %. Besides, the developed dressings possessed outstanding biocompatibility, universal adhesion and self-healing ability. More importantly, the PAAm-XG hydrogels can be successfully loaded with Cefixime and human recombinant epidermal growth factor, and these loaded hydrogels released these bioactive molecules in sustained ways. As a result, both E. coli and S. aureus bacteria were inactivated after contacting with the Cefixime-loaded hydrogels for 24 h. Furthermore, in vivo data demonstrated that the PAAm-XG hydrogel dressings significantly accelerated the wound healing in a mouse model. All of these indicate that the multifunctional PAAm-XG hydrogels are promising candidates for wound treatment.

Polyvinyl alcohol/xanthan gum composite film with excellent food packaging, storage and biodegradation capability as potential environmentally-friendly alternative to commercial plastic bag

Polyvinyl alcohol (PVA)-xanthan gum (XG) composite films with good degradation properties were prepared by casting method. The effects of XG amount on thickness, moisture content, water solubility, water vapor transmission (WVP), transmittance and mechanical properties of the composite film were investigated. All composite films produced uniform and transparent films and Fourier transform infrared (FT-IR) spectroscopy, as well as X-ray diffraction (XRD) had proven the formation of hydrogen bonds and subsequently compatibility of the two polymers. In general, addition of XG in PVA was able to decrease moisture content, water solubility and WVP more than the pure PVA films, with sample PX30 demonstrated the best performance. This sample also had the best mechanical properties. It also demonstrated food packaging and capability better than that of commercial plastic bag. More importantly, our sample can be fully decomposed in soil and water within 12 h, which was not only significantly shorter than commercial plastic bag, but also other biodegradable materials. Therefore, PVA/XG-based food packaging material has demonstrated huge potential to be commercialized and replaces commercial plastic bag as an alternative packing material which is renewable, sustainable and environmentally friendly.

Assessment of shear-thinning fluids and strategies for enhanced in situ removal of heavy chlorinated compounds-DNAPLs in an anisotropic aquifer

The removal of chlorinated organic hydrocarbons (COHs) -DNAPLs was studied in permeability-contrasted sandboxes with an egg-box shaped substratum. Aqueous solutions were compared to viscous shear-thinning fluids (xanthan solution and foam). Interfacial and viscous effects were compared by increasing the capillary number of injected fluids. Non-spatially targeted DNAPL recovery (NSTR) where the driving force was the injection pressure, was compared to spatially targeted DNAPL recovery (STR) where a pumping system allowed the controlled flow. A historical contamination made of a complex mixture of COHs and hexachlorobutadiene (HCBD) as a model were used. NSTR results showed that DNAPL recovery with non-viscous liquids did not exceed 40%. The best results were obtained for xanthan solutions with surfactant ~ 1.3 ×CMC for which pure phase recovery amounted to 88% and 93% for HCBD and for the historical DNAPL, respectively. The STR strategy showed similar recovery yields, whereas xanthan concentrations were 10-times lower. Mass balances on DNAPL showed that at most, 0.15% of COHs was dissolved in the aqueous effluents. NZVI (1 g.l^-1) were delivered in xanthan in view of the chemical degradation of residual COHs and showed a 65% transmission through the low permeability soil.

Use of xanthan gum for whole cell immobilization and its impact in bioremediation - a review

Xanthan gum is one of the exo-polysaccharides produced by bacteria and is characterized by unique non-Newtonian properties. Its structure and conformation strongly depend on the fermentation conditions and such factors as temperature and ions concentration. The properties of the xanthan gum were appreciated in the controlled drug delivery but in the crosslinked form. Due to its ability to enhance the survival rate of immobilized bacteria, the potential of a crosslinked form is promising. Unfortunately, xanthan gum crosslinking procedures often require toxic substances or harsh environmental conditions, which cannot be used in the entrapment of living cells. In this study, we summarised a crosslinking method that could potentially be modified to reduce its toxicity to living cells. Moreover, this review also includes using xanthan gum in bioremediation studies and possible utilization methods to avoid carrier accumulation in the environment.

Harnessing the potential of dialdehyde alginate-xanthan gum hydrogels as niche bioscaffolds for tissue engineering

Biomimetic hydrogels composed of natural polysaccharides have invariably blossomed as niche biomaterials in tissue engineering applications. The prospects of creating an extracellular matrix (ECM)-like milieu from such hydrogels has garnered considerable importance. In this study, we have fabricated bioscaffolds comprising dialdehyde alginate and xanthan gum and explored their potential use in tissue regeneration. The fabricated scaffolds displayed an interconnected porous network structure that is highly desirable for the aforesaid application. The scaffolds were endowed with good mechanical properties, thermostability, protein adsorption efficacy and degradability. Curcumin-loaded hydrogels exhibited appreciable antibacterial activity against E. coli. In vitro cytocompatibility studies revealed that the scaffolds promoted adhesion and proliferation of 3T3 fibroblast cells. The Western blot analysis of p53 gene indicated no growth arrest or apoptosis in 3T3 cells thus, signifying the non-toxic nature of the scaffolds. Furthermore, the ECM formation was confirmed via SDS-PAGE analysis. The overall results clearly validated these scaffolds as effectual biomaterials for tissue engineering applications.