A sterilizable platform based on crosslinked xanthan gum for controlled-release of polymeric micelles: Ocular application for the delivery of neuroprotective compounds to the posterior eye segment

TPGS (D-α-tocopheryl polyethylene glycol 1000 succinate) polymeric micelles show interesting properties for ocular administration thanks to their solubilization capability, nanometric size and tissue penetration ability. However, micelles formulations are generally characterized by low viscosity, poor adhesion and very short retention time at the administration site. Therefore, the idea behind this work is the preparation and characterization of a crosslinked film based on xanthan gum that contains TPGS micelles and is capable of controlling their release. The system was loaded with melatonin and cyclosporin A, neuroprotective compounds to be delivered to the posterior eye segment. Citric acid and heating at different times and temperatures were exploited as crosslinking approach, giving the possibility to tune swelling, micelles release and drug release. The biocompatibility of the platform was confirmed by HET-CAM assay. Ex vivo studies on isolated porcine ocular tissues, conducted using Franz cells and two-photon microscopy, demonstrated the potential of the xanthan gum-based platform and enlightened micelles penetration mechanism. Finally, the sterilization step was approached, and a process to simultaneously crosslink and sterilize the platform was developed.

A self-assembling hydrogel nanocomposite based on xanthan gum modified with SiO2 NPs and HPAM for improved adsorption of crystal violet cationic dye from aqueous solution

This paper presents the rational design and novel synthesis of multifunctional nanocomposite hydrogel derived from xanthan gum (XG) modified with silica nanoparticles and partially hydrolyzed polyacrylamide (HPAM) via H-bonding interactions (self-assembly) through the "green" gelation process in water. Different techniques have been employed to characterize HPAM/SiO2@XG, including FT-IR, FE-SEM, XRD, TEM, BET, and TG/DTG as well as swelling kinetics. Crystal violet (CV)'s adsorption performance was investigated using batch experiments by varying various variables involving adsorbent composition, pH, adsorbent quantity, contact time, CV concentration, ionic strength, and temperature. A well-fitting Langmuir isotherm was found for the adsorption data at 30 °C and pH 7.0, yielding 342.19 mg CV/g as the equilibrium state's maximum adsorption (qm). CV adsorption data agreed better with the pseudo-second-order model than other kinetic models. Furthermore, the HPAM/SiO2@XG nanocomposite hydrogel showed a significant increase in adsorption capacity over the SiO2@XG hydrogel precursor. According to thermodynamic analysis, CV adsorbs to HPAM/XG@SiO2 spontaneously and exothermically. Our results showed that the nanocomposite hydrogel's functional groups interact with CV predominantly through electrostatic interactions, coupled with H-bonding. Nanocomposite hydrogel has been regenerated using a five-cycle adsorption-desorption process, and the efficiency of CV removal has remained a satisfactory level of removal efficiency (94.5 % to 71.5 %).

Molecular modification of low-dissolution soy protein isolates by anionic xanthan gum, neutral guar gum, or neutral konjac glucomannan to improve the protein dissolution and stabilize fish oil emulsion

Herein, the effects of anionic xanthan gum (XG), neutral guar gum (GG), and neutral konjac glucomannan (KGM) on the dissolution, physicochemical properties, and emulsion stabilization ability of soy protein isolate (SPI)-polysaccharide conjugates were studied. The SPI-polysaccharide conjugates had better water dissolution than the insoluble SPI. Compared with SPI, SPI-polysaccharide conjugates had lower β-sheet (39.6 %-56.4 % vs. 47.3 %) and α-helix (13.0 %-13.2 % vs. 22.6 %) percentages, and higher β-turn (23.8 %-26.5 % vs. 11.0 %) percentages. The creaming stability of SPI-polysaccharide conjugate-stabilized fish oil-loaded emulsions mainly depended on polysaccharide type: SPI-XG (Creaming index: 0) > SPI-GG (Creaming index: 8.1 %-21.2 %) > SPI-KGM (18.1 %-40.4 %). In addition, it also depended on the SPI preparation concentrations, glycation times, and glycation pH. The modification by anionic XG induced no obvious emulsion creaming even after 14-day storage, which suggested that anionic polysaccharide might be the best polysaccharide to modify SPI for emulsion stabilization. This work provided useful information to modify insoluble proteins by polysaccharides for potential application.

Biofilm hydrogel derived from physical crosslinking (self-assembly) of xanthan gum and chitosan for removing Cd2+, Ni2+, and Cu2+ from aqueous solution

This study aimed to fabricate a series of biodegradable hydrogel films by gelating/physically crosslinking a blend of xanthan gum (XG) and chitosan (CS) in various combinations using a facile, green, and low cost solution casting technique. The adsorption of Cd2+, Cu2+ and Ni2+ by the XG/CS biofilm in aqueous solution was studied in batch experiments to determine how the pH of the solution, contact time, dosage of adsorbent, initial metal ion concentration and ionic strength affect its adsorption. A highly pH-dependent adsorption process was observed for three metal ions. A maximum amount of Cd2+, Ni2+, and Cu2+ ions was adsorbable with 50 mg of the adsorbent at pH 6.0 for an initial metal concentration of 50 mg.L-1. An empirical pseudo-second-order model seems to fit the kinetic experimental data reasonably well. It was found that the Langmuir model correlated better with equilibrium isotherm when compared with the Freundlich model. For Cd2+, Ni2+, and Cu2+ ions at 25 °C, the maximum monolayer adsorption capacity was 152.33, 144.79, and 139.71 mg.g-1, respectively. Furthermore, the biofilm was capable of regenerating, allowing metal ions to adsorb and desorb for five consecutive cycles. Therefore, the developed biodegradable film offers the potential for remediation of specified metal ions.

Self-adhesive, freeze-tolerant, and strong hydrogel electrolyte containing xanthan gum enables the high-performance of zinc-ion hybrid supercapacitors

Hydrogel electrolyte is an ideal candidate material for flexible energy storage devices due to its excellent softness and conductivity properties. However, challenges such as the inherent mechanical weakness, the susceptibility to be frozen in low-temperature environments, and the insufficiency of hydrogel-electrode contact persist. Herein, a "Multi in One" strategy is employed to effectively conquer these difficulties by endowing hydrogels with high strength, freeze-resistance, and self-adhesive ability. Multiple hydrogen bond networks and ion crosslinking networks are constructed within the hydrogel electrolyte (PVA/PAAc/XG) containing polyvinyl alcohol (PVA), acrylic acid (AAc), and xanthan gum (XG), promoting the enhanced mechanical property, and the adhesion to electrode materials is also improved through abundant active groups. The introduction of zinc ions provides the material with superior frost resistance while also promoting electrical conductivity. Leveraging its multifunction of superior mechanical strength, anti-freeze property, and self-adhesive characteristic, the PVA/PAAc/XG hydrogel electrolyte is employed to fabricate zinc ion hybrid supercapacitors (ZHS). Remarkably, ZHS exhibits outstanding electrochemical performance and cycle stability. A remarkable capacity retention rate of 83.86 % after 10,000 charge-discharge cycles can be achieved at high current densities, even when the operational temperature decreases to -60 °C, showing great potential in the field of flexible energy storage devices.

Effects of alternative sweeteners with or without xanthan gum on the physicochemical properties of scone products

The physicochemical properties of scones made with alternative sweeteners (stevia, sucralose, and allulose) at different ratios (30, 70, and 100%) with or without xanthan gum were investigated. Nineteen samples were evaluated for crust color, moisture content, specific volume, and texture properties. Scones with allulose had lower L values but higher a and b values due to the Maillard and caramelization reactions. The moisture content increased with xanthan gum addition, thereby decreasing the specific volume. The sample with 30% of stevia (ST30), 30% of sucralose (SC30), and 30% of allulose and xanthan gum (AL30G) had similar characteristics to the sample with sucrose (CON). In the consumer acceptance test, CON was the most preferred, but ST30 showed no significant difference. AL30G was less preferred because of its lack of sweetness. Overall, the physicochemical properties and consumer acceptance of ST30 were closest to those of CON, suggesting its potential use in scone products.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01416-9.

Synergistic impact of natural gums and crosslinkers on the properties of oilseed meals based biopolymeric films

The waste material utilization from available agricultural resources can be beneficial in the field of economic, social, and environmental well-being. One of the main industrial crops used to manufacture oil from oilseeds worldwide is agricultural waste, such as the cake made from oilseeds. In this study, de-oiled cakes are used to create biopolymeric films. Three widely accessible oilseed meals viz. flaxseed, soybean, and mustard were gathered, ground, and sieved. A film forming suspension of defatted meals along with natural gums (acacia and xanthan gum) and crosslinkers (citric acid and glutaraldehyde) were formed. The suspension was cast into petri dishes and dried to produce smooth and even films. The physical, functional, color, thermal and morphological properties of the oilseed meals-gums crosslinked biopolymeric film were evaluated and statistical analysis was performed. The solubility was found to be decreased and tensile strength was increased with the addition of citric acid and increase in tensile strength. There was significant difference observed in the values of elongation at break after addition of citric acid as crosslinker. The research shows how oilseed meals enriched with natural gum and crosslinkers may be converted into biopolymeric films, which can then be used in food packaging to lessen reliance on petroleum-based, non-biodegradable plastics.

Review on emerging trends and challenges in the modification of xanthan gum for various applications

This review explores the realm of structural modifications and broad spectrum of their potential applications, with a special focus on the synthesis of xanthan gum derivatives through graft copolymerization methods. It delves into the creation of these derivatives by attaching functional groups (-OH and -COOH) to xanthan gum, utilizing a variety of initiators for grafting, and examining their diverse applications, especially in the areas of food packaging, pharmaceuticals, wastewater treatment, and antimicrobial activities. Xanthan gum is a biocompatible, biodegradable, less toxic, bioactive, and cost-effective natural polymer derived from Xanthomonas species. The native properties of xanthan gum can be improved by cross-linking, grafting, curing, blending, and various modification techniques. Grafted xanthan gum has excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing ability. Owing to its remarkable properties, such as biocompatibility and its ability to form gels resembling the extracellular matrix of tissues, modified xanthan gum finds extensive utility across biomedicine, engineering, and the food industry. Furthermore, the review also covers various modified derivatives of xanthan gum that exhibit excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing abilities. These applications could serve as important resources for a wide range of industries in future product development.

A comparative study on the rheological properties of concentrated xanthan gum in combination with gum arabic or gum arabic-based emulsion

A goal of this study is to explore the difference in rheological properties of xanthan gum (XG)-based mixtures with gum arabic (GA) or GA-based emulsion (GAE). The stability of GAE was improved by thickening with XG. The intrinsic viscosity of all mixtures decreased as GA concentration increased, implying an XG conformational transition from the disordered to the ordered form. All mixtures except for an XG-GA mixture at 6.0 % GA attained a higher consistency index value than XG alone, indicating synergistic interactions between the components. At a high GA concentration (>3.0 %), the XG-GAE mixture showed higher relative apparent viscosity values than the XG-GA mixture. All mixtures except for an XG-GA mixture at 6.0 % GA showed higher elastic modulus and lower viscous modulus values than XG alone. Consequently, all mixtures showed lower tan δ values (0.26-0.30) than XG alone (0.31). Moreover, with a high GA concentration (>1.5 %), the XG-GAE mixtures achieved lower relative tan δ values than XG-GA mixture. These results indicate that XG formed a higher weak gel-like network with GAE than GA. Overall, the findings demonstrate that the interaction between XG and GA is influenced by conformational changes in the latter in both aqueous and emulsion systems.

Research progresses on carboxymethyl xanthan gum: Review of synthesis, physicochemical properties, rheological characterization and applications in drug delivery

Xanthan gum is a nonionic polysaccharide widely explored in biomedical, nutraceutical, and pharmaceutical fields. XG suffers from several drawbacks like poor dissolution, lower bioavailability and an inability to form hydrogels. The carboxymethyl derivative of XG, CMX, has better solubility, dissolution, and bioavailability characteristics. Moreover, due to its anionic character, it forms water insoluble hydrogels upon crosslinking with metal cations. CMX hydrogels are used to prepare matrix tablets, microparticles, beads, and films. CMX hydrogels has been used in drug delivery and tissue engineering fields. CMX hydrogels are used for sustained gastrointestinal, colon targeted, and transdermal delivery of drugs. CMX nanoparticles have been used for targeted delivery of anticancer drugs to tumor cells. CMX hydrogels have already made significant strides in drug delivery and tissue engineering fields. Further understanding of the physicochemical properties and rheological characteristics of CMX would enable researchers to explore newer applications of CMX. This review article thus aims to discuss the synthesis, physicochemical properties, and rheological characteristics of CMX. The article also gives critical insights on the versatility of CMX as a drug delivery carrier and presents prospective trends on applications of CMX.

Chitosan and silica nanoparticles-modified xanthan gum-derived bio-nanocomposite hydrogel film for efficient uptake of methyl orange acidic dye

In this contribution, a bio-nanocomposite hydrogel film (CS/XG.SiO2) of chitosan/silica NPs-modified xanthan gum was prepared via a facile solution casting blending approach and utilized to capture the anionic methyl orange (MO) from aqueous solution. A Taguchi standard method was used to optimize the hydrogel nanocomposite synthesis reaction conditions after comprehensive characterization using various techniques. Under various operating parameters, the hydrogel biofilm was tested for its effectiveness in adsorbing MO dye in a batch process. In agreement with Langmuir isotherm, the CS/XG.SiO2 biofilm was capable of adsorbing MO at a maximum capacity of 294 mg/g at pH 5.30, contact time 45 min, temperature 25 °C, and concentration (C0) 50 mg/L. Pseudo-second-order model and adsorption kinetics data well matched. The thermodynamic data indicate that adsorption occurred spontaneously and exothermically. The main mechanisms driving the adsorption are electrostatic interactions and hydrogen bonding between the CS/XG.SiO2 nanocomposite and the dye. Furthermore, the biofilm is regenerative, allowing for up to five reuses while maintaining a 75 % dye removal efficiency. This study highlights that the CS/XG.SiO2 hydrogel nanocomposite is an inexpensive, reusable, and eco-friendly bio-adsorbent that is capable of anionic dye adsorption.

Development of a novel bionanocomposite of UiO-66/xanthan gum/alginate crosslinked by calcium chloride for azo dye removal: Insight into adsorption kinetics, isotherms, and thermodynamics

In the present work, UiO-66/xanthan gum/alginate bionanocomposite adsorbent was fabricated using the in-situ crosslinking-gelation method, characterized by different techniques, and finally used for the removal of methylene blue dye from aqueous solution. Adsorption studies were performed using batch experiments and the influencing operational parameters such as contact time, initial pH solution, temperature, initial dye concentration, adsorbent dose, pHPZC, swelling, regeneration, and reuse of the adsorbent were investigated. The various kinetic models (pseudo-first-order, pseudo-second-order, Elovich, and intraparticle diffusion) and isotherm models (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich) were used to analysis of the experiment results. The results were best fitted to the pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption capacity of dye on the adsorbent was obtained at 9.96 mg/g at pH = 11. The value of pHPZC for the adsorbent was obtained at about 8. According to thermodynamic parameters, the dye adsorption was found as spontaneous and endothermic due to the negative value of the ΔG° and ΔH°. After 4 times of reusability cycles, the adsorption efficiency remained above 86 %, which represented a certain regeneration ability. As a result, this research indicates that UiO-66/xanthan gum/alginate bionanocomposite can be utilized as a promising bio-adsorbent for azo dye removal from contaminated wastewater.

Production and application of xanthan gum-prospects in the dairy and plant-based milk food industry: a review

Xanthan gum (XG) is an important industrial microbial exopolysaccharide. It has found applications in various industries, such as pharmaceuticals, cosmetics, paints and coatings, and wastewater treatment, but especially in the food industry. The thickening and stabilizing properties of XG make it a valuable ingredient in many food products. This review presents a comprehensive overview of the various potential applications of this versatile ingredient in the food industry. Especially in the plant-based food industries due to current interest of consumers in cheaper protein sources and health purposes. However, challenges and opportunities also exist, and this review aims to identify and explore these issues in greater detail. Overall, this article represents a valuable contribution to the scientific understanding of XG and its potential applications in the food industry.

Impact of Whey Protein Isolate and Xanthan Gum on the Functionality and in vitro Digestibility of Raw and Cooked Chestnut Flours

Due to the limitations of the properties of chestnut flour, its applications have been restricted. The objective of this study is to investigate the impact of whey protein isolate (WPI) and xanthan gum (XG) on the functional and digestive properties of chestnut flour, specifically focusing on gel texture, solubility and swelling power, water absorption capacity, freeze-thaw stability and starch digestibility. The addition of both WPI and XG reduced the gel hardness, gumminess and chewiness of the co-gelatinized and physically mixed samples. Furthermore, the inclusion of physically mixed WPI and XG led to an increase in the solubility (from 58.2 to 75.0%) and water absorption capacity (from 3.11 to 5.45 g/g) of chestnut flour. The swelling power of the chestnut flour was inhibited by both additives. WPI was superior to XG at maintaining freeze-thaw stability, by reducing the syneresis from 71.9 to 68.1%. Additionally, WPI and XG contributed to the inhibition of starch hydrolysis in the early stage of digestion, resulting in a lower starch digestibility of chestnut flours. This research provides insights into the interaction mechanisms between WPI, XG, and chestnut flour, offering valuable information for the development of chestnut flour products with enhanced properties.

Co-delivery of vitamin C and β-carotene in W/O/W emulsions stabilized by modified aggregated insoluble soybean protein hydrolysate-xanthan gum complexes

Environmentally friendly emulsifiers safe for human consumption are urgently needed to stabilize emulsions for applications in the food industry. In this study, we prepared complexes combining modified aggregated insoluble soybean protein hydrolysate (AISPH) mixed with xanthan gum (XG) (0.05-0.3 %, w/v), and further to construct water-in-oil-in-water (W/O/W) emulsions to deliver vitamin C and β-carotene. We observed a decrease in the AISPH α-helix and β-sheet content, surface hydrophobicity, and fluorescence intensity all decreased after binding. In contrast, the particle size and absolute ξ-potential significantly increased, indicating that molecular non-covalent interactions occurred in the solution. The emulsification property of AISPH was also improved by adding XG, and the AISPH-XG-stabilized emulsion showed improved stability, encapsulation efficiency, and rheological properties. Among them, AISPH-XG-0.25-stabilized emulsion exhibited a smaller particle size (8.41 ± 0.49 μm) and the highest encapsulation efficiency for vitamin C (90.03 ± 0.23 %) and β-carotene (70.56 ± 0.06 %). Additionally, simulated gastric digestion indicated that vitamin C and β-carotene bioavailability increased by 3.6 and 5.8 times, respectively. Finally, the emulsion exhibited good pH, ionic, and thermal stability. In general, AISPH-XG-stabilized W/O/W emulsions showed good stability and carrying capacity, providing a theoretical basis for improving their application.

Physicochemical properties and stability of oil-in-water emulsions stabilized by soy protein isolate and xanthan gum

The aim of this work was to determine rheological and disperse characteristics and stability of oil-in-water emulsions stabilized by soy protein isolate (SPI) and xanthan gum (XG), as natural components. The effects of their combination on emulsion stabilization have not been investigated yet. The existence of interactions between the two macromolecules were indicated by the influence of XG on SPI surface hydrophobicity and surface tension values. Increase in SPI concentration from 1 to 3 % shift of distribution curves towards smaller particle size, while the opposite effects of further increase of SPI was obtained. The emulsions stabilized by SPI showed shear-thinning flow behavior, which changed to thixotropic at 5 % of SPI concentration. The presence of XG in emulsions at low concentrations did not affect the size distribution of the droplets, while at 0.1 % of XG Sauter mean diameter value raised and distribution curves were shifted towards a higher particle size. The presence of XG at higher concentration resulted in thixotropic flow behavior of emulsions. Also, increase in XG concentration led to the increase in consistency index and extent of non-Newtonian behavior of emulsions and enhanced the influence of the elastic modulus and creaming stability of the systems.

Data-driven intelligent modeling, optimization, and global sensitivity analysis of a xanthan gum biosynthesis process

In this study, the focus was to produce xanthan gum from pineapple waste using Xanthomonas campestris. Six machine learning models were employed to optimize fermentation time and key metabolic stimulants (KH2PO4 and NH4NO3). The production of xanthan gum was optimized using two evolutionary optimization algorithms, particle swarm optimization, and genetic algorithm while the importance of input features was ranked using global sensitivity analysis. KH2PO4 was the most important input and was found to be beneficial for xanthan gum production, while a limited amount of nitrogen was needed. The extreme learning machine model was the most adequate for modeling xanthan gum production, predicting a maximum xanthan yield of 10.34 g/l (an 11.9 % increase over the control) at a fermentation time of 3 days, KH2PO4 of 15 g/l, and NH4NO3 of 2 g/l. This study has provided important insights into the intelligent modeling of a biostimulated process for valorizing pineapple waste.

Structural, mechanical, barrier and antioxidant properties of pectin and xanthan gum edible films loaded with grapefruit essential oil

This research focused on the development of films based on pectin and xanthan gum composite loaded with different concentrations of grapefruit essential oil (GFO). The fabricated films were characterized to assess the effect of GFO on the structural, mechanical, barrier, chemical, and antioxidant properties. The addition of GFO enhanced the functional properties of the films, as confirmed by FTIR analysis showing molecular interactions within the film matrix. SEM observations revealed that films with higher GFO content had a smoother, more compact structure with uniform oil distribution. Films loaded with oil demonstrated enhanced water resistance, as their decreased permeability ranged from 0.733 ± 0.009 to 0.561 ± 0.020 (g mm)/(m2.h.kPa). Additionally, these films showed a notable increase in tensile strength, ranging from 2.91 ± 0.19 to 8.55 ± 0.62 MPa. However, the addition of oil led to a reduction in the elongation at break of the films, which decreased from 52.84 ± 3.41 % to 12.68 ± 1.52 %, and a decline in transparency from 87.57 ± 0.65 % to 76.18 ± 1.12 %. Fabricated films exhibited enhanced antioxidant properties, as evidenced by increased DPPH• and ABTS•+ radical scavenging activities with the addition of GFO. The findings of the current study suggest that GFO is an effective natural additive for enhancing the physiochemical properties of pectin and xanthan gum-based films, making them more suitable for food packaging applications.

Waste to value: Enhancing xanthan gum hydrogel with wine lees extract for optimal performance

The current study investigated the potential of utilizing wine lees extract (WLE) from red wine to enhance the sustainability and cost-effectiveness of xanthan gum (XG). A novel hydrogel system was successfully generated by cross-linking WLE and XG. Response surface methodology (RSM) was used to thoroughly analyze the characteristics of this novel hydrogel to understand its behavior and possible applications. Consistency index (K), flow behavior index (n), water holding capacity (%), and oil binding capacity (%) of the cross-linked hydrogels were optimized, and the best formulation was determined to be 0.81 % XG + 0.67 % WLE and crosslink temperature of 47 °C. The addition of WLE (0-1 % w/v) to different concentrations of XG (0-1 % w/v) was found to have a notable impact on the rheological properties, but changes in cross-link temperature (45-65 °C) did not have a significant effect. The activation energy was increased by incorporating WLE at XG concentration above 0.5 %, indicating a more robust and stable structure. FTIR and SEM analyses confirmed the chemical bonding structure of the optimum hydrogel. Incorporating WLE could significantly improve the functional properties of XG hydrogels, allowing the development of healthier product formulations.

Investigating the rheological properties and 3D printability of tomato-starch paste with different levels of xanthan gum

Tomato is an inexpensive vegetable with high nutritional value，but it does not have the suitable self-supporting ability for 3D printing. Xanthan gum (XG) is a common thickener that may improve 3D printability of tomatoes paste. This study evaluated the printability of tomato-starch paste (TSP) by examining its rheological and textural properties and microstructure of 3D samples. The rheological results showed that apparent viscosity, recovery rate, storage modulus, loss modulus, initial and average rheological forces, and shear stress increased significantly (P < 0.05) with increase of XG levels in tomato-starch paste. The low-field NMR results showed that T21 and T22 of the TSP decreased with increase of XG levels (P < 0.05). With increase of XG levels, a dense network structure in the TSP was formed as observed in the microstructural images. The TSP with 5 g/kg XG had the highest printing accuracy, and the textural property showed that the addition of 5 g/kg of XG significantly improved the hardness, elasticity, and chewability of TSP (P < 0.05). Overall, with increase of XG levels the fluidity of the pseudoplastic gel formed by the tomato-starch system and increased the density of the structure, resulting in improved extrudability, shape stability, and self-supporting property.

Development of thiolated xanthan gum-stearylamine conjugate based mucoadhesive system for the delivery of biochanin-A to melanoma cells

Recently, instead of creating new active compounds, scientists have been working to increase the bioavailability and residence time of existing drugs by modifying the characteristics of the delivery systems. In the present study, a novel mucoadhesive bioconjugate (SN-XG-SH) was synthesized by functionalizing a polysaccharide xanthan gum (XG) with cysteamine hydrochloride (CYS) and a lipid stearylamine (SN). FTIR, CHNS and 1H NMR studies confirmed the successful synthesis of SN-XG-SH. Mucoadhesion of the thiolated XG was enhanced and evaluated by different methods. Disulfide bond formation between thiolated XG and skin mucus enhances mucoadhesive behavior. The mucoadhesive bioconjugate was used to prepare nanoparticles for the delivery of hydrophobic biochanin-A (Bio-A) for the treatment of melanoma. The thiolated xanthan gum nanoparticles also demonstrated high drug entrapment efficiency, sustained drug release, and high storage stability. The drug loaded nanoparticles (Bio-A@TXNPs) significantly improved the cytotoxicity of Bio-A against human epidermoid cancer cells (A431 cells) by inducing apoptosis and changing mitochondrial membrane potential. In conclusion, thiolation of XG improves its mucoadhesive properties and prolongs the release of Bio-A. Thus, thiolated XG conjugate has a high potential for use as a bioadhesive agent in controlled and localised delivery of drugs in different skin diseases including melanoma.

Effect of in-situ biochemical modification on the synthesis, structure, and function of xanthan gum based bacterial cellulose generated from Tieguanyin oolong tea residue hydrolysate

The effect of in-situ biochemical modification on the synthesis, structure, and function of xanthan gum based bacterial cellulose generated from Tieguanyin oolong tea residue hydrolysate was evaluated for the first time. This modification could overcome the inhibitory effect of the hydrolysate and the bacterial cellulose yield with 0.6% xanthan gum addition increased by 260.8% compared with that without xanthan gum addition. Bacterial cellulose and xanthan gum were combined by the in-situ modification and the alteration of fermentation medium rheological properties by xanthan gum addition might be beneficial for their combination. The average diameter of the bacterial cellulose microfibrils was increased by the modification, and it had a great influence on the crystalline structure of the bacterial cellulose. Additionally, both the water absorption and texture properties of the bacterial cellulose was strengthened by the modification. Overall, this modification showed great potential for efficient and effective xanthan gum based bacterial cellulose production.

Evolutions of synergistic binding between konjac glucomannan and xanthan with high pyruvate group content induced by monovalent and divalent cation concentration

Synergistic interaction gels could be formed by synergistic type-A and type-B bindings between konjac glucomannan (KGM) and xanthan during cooling. Adding salt ions significantly altered those bindings and thus the gel-related properties. The results showed that adding NaCl or CaCl2 eliminated type-B binding due to an electrostatic shielding effect. Adding NaCl or CaCl2 (3 and 6 mM) enhanced type-A binding by neutralizing the negative charge of COOH and reducing the electrostatic repulsion among xanthan chains, as evidenced by an increase in the onset temperature of exotherm peak, the formation of more parallel multiple filaments, and an increase in aggregation structures (>1.0 nm) and gel hardness. When CaCl2 concentration was higher, Ca2+ bridged side-chain clusters into more complex structures, which would hardly participate in the formation of helical structures and weaken type-A binding. The results obtained are beneficial for the rational design and preparation of KGM/xanthan gels with synergistic interaction.

The Effect of Ionic Strength on the Formation and Stability of Ovalbumin-Xanthan Gum Complex Emulsions

Protein-polysaccharide complexes have been widely used to stabilize emulsions, but the effect of NaCl on ovalbumin-xanthan gum (OVA-XG) complex emulsions is unclear. Therefore, OVA-XG complex emulsions with different XG concentrations at pH 5.5 were prepared, and the effects of NaCl on them were explored. The results indicated that the NaCl significantly affected the interaction force between OVA-XG complexes. The NaCl improved the adsorption of proteins at the oil-water interface and significantly enhanced emulsion stability, and the droplet size and zeta potential of the emulsion gradually decreased with increasing NaCl concentrations (0-0.08 M). In particular, 0.08 M NaCl was added to the OVA-0.2% XG emulsion, which had a minimum droplet size of 18.3 μm. Additionally, XG as a stabilizer could improve the stability of the emulsions, and the OVA-0.3% XG emulsion also exhibited good stability, even without NaCl. This study further revealed the effects of NaCl on emulsions, which has positive implications for the application of egg white proteins in food processing.

Evaluation of the impact of tragacanth/xanthan gum interpolymer complexation with chitosan on pharmaceutical performance of gels with secnidazole as potential periodontal treatment

Periodontitis consists a group of dental disorders that affect about 70 % of the world population. The therapy mainly relies on mechanical removing bacterial biofilm, nevertheless, local or systemic antibacterial agents play a key role in treating the acute conditions. Secnidazole is a newer derivative of commonly used metronidazole with high safety profile and broad spectrum of antimicrobial activity. The aim of the study was to evaluate the applicability of polyelectrolyte complex-based hydrogels composed of anionic tragacanth with addition of xanthan gum and cationic chitosan as carriers for buccal/intra pocket delivery of secnidazole. Prepared hydrogels with 5 % and 10 % (w/w) drug content were evaluated pharmaceutically towards inter alia physicomechanical, rheological and thermal properties, drug release kinetics, swelling behavior or antimicrobial activity. Cytotoxicity against human primary umbilical vein endothelial cells was also assessed with two independent method. Stable compositions with secnidazole were obtained, however, various miscibility of the drug with the polymers was noted. By adding chitosan, antibacterial activity and swelling performance of the gels were improved, nevertheless, drop of the mucoadhesiveness was also recorded. Hydrogels with 5 % secnidazole were selected as effective antimicrobial compositions with the highest cytocompatibility. They might be considered as promising for oromucosal application with special attention given to SEC as an alternative locally administered antimicrobial agent.

Fabrication and characterization of dihydromyricetin-loaded microcapsules stabilized by glyceryl monostearate and whey protein-xanthan gum

Dihydromyricetin (DMY) is a lipophilic nutrient with various potential health benefits; however, its poor storage stability and low solubility and bioavailability limit its applications. This study aims to encapsulate DMY in microcapsules by membrane emulsification and freeze-drying methods to overcome these issues. Glyceryl monostearate (GMS, solid lipid) and octyl and decyl glycerate (ODO, liquid lipid) were applied as the inner cores. Whey protein and xanthan gum (XG) were used as wall materials. The prepared microcapsules had an irregular blocky aggregated structure with rough surfaces. All the microcapsules had a DMY loading of 0.85 %-1.1 % and encapsulation efficiency (EE) >85 %. GMS and XG increased the DMY loading and EE. The addition of GMS and an increased XG concentration led to a decrease in the rehydration rate. The in vitro release and digestion studies revealed that GMS and XG controlled the release and digestion of DMY. The chemical stability results indicated that GMS and XG protected DMY against oxidation. An antioxidant capacity study showed that GMS and XG helped DMY in the microcapsules exert antioxidant effects. This research study provides a platform for designing microcapsules with good stability and high bioavailability to deliver lipophilic bioactive compounds.

Foam-templated oleogels constructed by whey protein isolate and xanthan gum: Multiple-effect delivery vehicle for Antarctic krill oil

To address the limitations of Antarctic krill oil (AKO) such as easy oxidation, unacceptable fishy flavor and low bioaccessibility of astaxanthin in it, a multiple-effect delivery vehicle for AKO is needed. In this study, whey protein isolate (WPI) and xanthan gum (XG) were utilized to construct AKO into oleogels by generating foam-templates. The effects of the concentration of XG on the properties of foam, cryogel and the corresponding oleogels were investigated, and the formation mechanism of oleogel was discussed from the perspective of the correlation between foam-cryogel-oleogel. The results demonstrated that with the increase of the concentration of XG, the foam stability was improved, the cryogel after freeze drying had a more uniform network structure and superior oil absorption ability, and the corresponding oleogel had excellent oil holding ability after oil absorption. The AKO oleogels showed superior oxidative stability compared with AKO. The in vitro digestion experiments demonstrated that the bioaccessibility of the astaxanthin in this oleogel was also considerably higher than that in AKO. In addition, this oleogel had masking effect on the odor-presenting substances in AKO, while retaining other flavors of AKO. The foam-templated oleogel can be considered as a multiple-effect vehicle for AKO to facilitate its application in food products. This study provides theoretical basis and data support for the development and utilization of novel vehicle for AKO, broadening the application of AKO in the field of food science.

Xanthan and gum acacia modified olive oil based nanoemulsion as a controlled delivery vehicle for topical formulations

In this study, olive oil nanoemulsion modified with xanthan gum and gum acacia was explored as a potential controlled topical delivery vehicle. Oil-in-water nanoemulsion formulated with optimized composition of olive oil, tween 80, and water was used as the drug carrier and further modified with gum. Effect of gum on nanoemulsion different physiochemical characteristics, stability, rheology, drug release and encapsulation efficiency were investigated. Results showed that developed nanoemulsion behaved as low viscosity Newtonian fluid and released 100 % drug within 6 h. Modification with xanthan and gum acacia had significantly improved formulation viscosity, drug encapsulation efficiency (>85 %) and controlled drug release up to 40 % with release pattern following Korsmeyer-Peppas model. Additionally, xanthan gum modified formulation exhibited shear thinning rheology by forming an extended network in the continuous phase, whereas gum acacia modified formulation behaved as Newtonian fluid at high shear rate (>200 s-1). Furthermore, xanthan gum modified formulations had improved zeta potential, stability, monodispersity, and hemocompatibility and showed high antibacterial activity against S. aureus than gum acacia modified formulations. These results indicate the higher potential of xanthan gum modified formulation as a topical delivery vehicle. Moreover, skin irritation test demonstrated the safety of developed formulations for topical application.

Instantaneous and reversible flocculation of Scenedesmus via Chitosan and Xanthan Gum complexation

An instantaneous and reversible flocculation method for Scenedesmus harvesting was developed, based on the complexation of Chitosan (CTS) and Xanthan Gum (XG). Under rapid stirring, Scenedesmus cells formed centimeter-sized flocs within 20 s using binary flocculants of 4 mg/L CTS and 16 mg/L XG. These flocs exhibited a remarkable harvest efficiency exceeding 95 % when filtered through 500-μm-pore-sized sieves. Furthermore, the flocs could be completely disintegrated by using alkaline or NaCl solutions (pH > 11 or NaCl concentration > 1.5 mol/L). Adjusting pH allowed recovery of 50 % CTS and 75 % XG, resulting in microalgae biomass with lower flocculant content and reducing reagent costs. Electrostatic interaction of -COO- of XG and -NH3+ of CTS deduced the formation of polyelectrolyte complexes (PECs), which shrink and wrap the coexisting algal cells to form the flocs under stirring. CTS and XG complexation was instantaneous and reversible, explaining quick flocculation and disintegration.

Conductive, water-retaining and knittable hydrogel fiber from xanthan gum and aniline tetramer modified-polysaccharide for strain and pressure sensors

Herein, we explored strategies for defoaming and controllable adjustment of spinnable and mechanical properties of polyanion polysaccharide-based hydrogels to fabricate conductive, water-retaining, and knittable hydrogel fibers for next-generation flexible electronics. Xanthan gum (XG) and aniline tetramer modified-polysaccharide (TMAT38) were crosslinked with sodium trimetaphosphate (STMP) and subsequently by Fe3+/Fe2+ ions coordination to prepare conductive and spinnable hydrogels. Polypropylene glycol was introduced as chemical antifoam, and solvent displacement method was adopted to improve mechanical and water-retaining properties. The glycerol-immersed XG5-TMAT38-STMP-Fe3+/CA-PPG hydrogel exhibited conductivity of 3.55×10-3-27.30×10-3 S/cm, storage modulus at linear viscoelastic region of 573 Pa-1717 Pa and self-healing percentage of 100 %-108 %. The 2 h glycerol-immersed hydrogel fibers with good flexibility, moisture retention and freezing tolerance were ready to bend and knit into fabrics. The hydrogel fiber braid possessed better conductivity, reliability and durability than the single hydrogel fiber as strain sensors. The hydrogel fiber fabric perceived tiny vibration triggered by swallowing, speaking and writing with good sensitivity and reproducibility. Furthermore, a three-component model was developed to evaluate response sensitivity and recoverability of the hydrogel fiber fabric-based pressure sensors, which facilitated understanding transient response of polymer-based hydrogel strain and pressure sensors.

Improvement of textural and sensory characteristics of aged rice using hydrothermal treatment with xanthan gum

Aged rice (AR) was mildly heated in aqueous dispersions containing different amounts of xanthan gum (Xan) at 60 °C for 1 h, and then dried in a humidity chamber (50 °C, 80% RH) for 12 h. The AR kernels treated without Xan showed a coarse surface with many pores after cooking, whereas the same rice treated with Xan showed a smooth and uniform surface. Prior to the treatment, the cooked AR was harder and less sticky than the cooked fresh rice (FR). The hydrothermal treatment softened the cooked AR although did not change its adhesiveness. The same treatment in the presence of Xan could increase the adhesiveness of AR, making the textural characteristics of AR similar to those of FR. Sensory evaluation revealed that the mild heat treatment in the presence of Xan restored the eating quality and acceptability of cooked AR which had been lost by aging.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-023-01306-0.

High-Fidelity Extrusion Bioprinting of Low-Printability Polymers Using Carbopol as a Rheology Modifier

Extrusion three-dimensional (3D) bioprinting is a promising technology with many applications in the biomedical and tissue engineering fields. One of the key limitations for the widespread use of this technology is the narrow window of printability that results from the need to have bioinks with rheological properties that allow the extrusion of continuous filaments while maintaining high cell viability within the materials during and after printing. In this work, we use Carbopol (CBP) as rheology modifier for extrusion printing of biomaterials that are typically nonextrudable or present low printability. We show that low concentrations of CBP can introduce the desired rheological properties for a wide range of formulations, allowing the use of polymers with different cross-linking mechanisms and the introduction of additives and cells. To explore the opportunities and limitations of CBP as a rheology modifier, we used ink formulations based on poly(ethylene glycol)diacrylate with extrusion 3D printing to produce soft, yet stable, hydrogels with tunable mechanical properties. Cell-laden constructs made with such inks presented high viability for cells seeded on top of cross-linked materials and cells incorporated within the bioink during printing, showing that the materials are noncytotoxic and the printed structures do not degrade for up to 14 days. To our knowledge, this is the first report of the use of CBP-containing bioinks to 3D-print complex cell-laden structures that are stable for days and present high cell viability. The use of CBP to obtain highly printable inks can accelerate the evolution of extrusion 3D bioprinting by guaranteeing the required rheological properties and expanding the number of materials that can be successfully printed. This will allow researchers to develop and optimize new bioinks focusing on the biochemical, cellular, and mechanical requirements of the targeted applications rather than the rheology needed to achieve good printability.

Synergistic enhancing effect of xanthan gum, carboxymethyl cellulose and citric acid on the stability of betacyanins in fermented red dragon fruit (Hylocereus polyrhizus) drink during storage

Nowadays, the demand for using healthy natural pigments (betacyanins) in the food industry is increasing. The present study aimed to overcome the circumstances that render the betacyanins instability in the red dragon fruit drink using mild approaches. These included optimised fermentation, incorporation of anionic polysaccharide mixture solution [xanthan gum (XG, 0.30-0.40 %, w/v) and carboxymethyl cellulose (CMC, 0.50-0.90 %, w/v)] and also addition of citric acid (CA, 0.05-0.20 %, w/v). The results of this study showed that the hydrocolloid mixture solution of XG and CMC significantly increased the samples' viscosity, pH and °Brix but reduced the aw, while betacyanins concentration had no significant change. The incorporation of CA at increasing concentration only reduced the samples' pH significantly without affecting the viscosity, aw and °Brix. Among all fermented samples, Formulation 3E (0.40 % XG + 0.50 % CMC + 0.20 % CA) had achieved the desired commercial reference viscosity while also successfully minimised betacyanins degradation from 60.18 % to 14.72 %, had the best pH stability and no significant change in viscosity, aw and °Brix values after 4-week storage at 25 °C. The fermented red dragon fruit drink with betacyanins stabilised by Formulation 3E can be produced and served as an independent functional drink product and as a stable, functional ingredient (natural colourant) for the food industry.

Effects of edible coatings and ultrasonic pretreatment on the phenolic content, antioxidant potential, drying rate, and rehydration ratio of sweet cherry

The target of this study was to examine the influence of ultrasound pretreatment and edible coatings (xanthan, guar, and wild sage seed gums) on the total phenols content, antioxidant potential, mass transfer rate, effective moisture diffusivity (Deff), and rehydration rate of sweet cherries (SC). For the edible coating of SC, a 0.2% gum solution (xanthan, guar, and wild sage seed) was prepared and the SC were dipped into the aqueous solution. Also, the ultrasound process (40 kHz and 150 W) was performed in an ultrasonic bath for 3 min. The gums coating increased the total phenols content, antioxidant properties, and drying time and decreased the Deff values. The highest value of DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging activity (61.04 ± 2.09%) was observed on coated SC by guar gum. The mean drying times for uncoated, xanthan gum-coated, guar gum-coated, and wild sage seed gum-coated SC were 130, 160, 175, and 140 min, respectively. In this study, the SC Deff as determined by the second Fick law varied from 1.39 × 10-9 m2/s to 2.46 × 10-9 m2/s. The Midilli model gave the best results for describing single-layer drying of SC. The mean rehydration ratio for uncoated, xanthan gum-coated, guar gum-coated, and wild sage seed gum-coated SC were 141.81, 167.26, 176.21, and 156.87 %, respectively. Considering the total phenols content, antioxidant activity, and rehydration ratio, edible coating and ultrasonic pretreatment will be more promising for SC pretreatment before drying and other processes.

Gum-based nanocomposites for the removal of metals and dyes from waste water

The importance of water for all living organisms is unquestionable and protecting its sources is crucial. In order to reduce water contaminants, like toxic metals and organic dyes, researchers are exploring different techniques, such as adsorption, photocatalytic degradation, and electrolysis. Novel materials are also being sought. In particular, biopolymers like guar gum and xanthan gum, that are eco-friendly, non-toxic, reusable, abundant and cost-effective, have enormous potential. Gum-based nanocomposites can be prepared and used for removing heavy metals and colored dyes by adsorption and degradation, respectively. This review explains the significance of gum-based nanomaterials in waste water treatment, including preparative steps, characterization techniques, kinetics models, and the degradation and adsorption mechanisms involved.

Fabrication of carboxymethyl starch/xanthan gum combinations Pickering emulsion for protection and sustained release of pterostilbene

Carboxymethyl starch (CMS)/xanthan gum (XG) combinations with different ratios (CMS/XG: 1/1, 3/1, 5/1, 7/1, 9/1, w/w) were used as Pickering emulsion delivery systems to encapsulate pterostilbene (PTS) to improve its stability. The results showed that the Pickering emulsion prepared using CMS/XG combinations could effectively encapsulate PTS. When the mass ratio of CMS to XG was 1:1, the encapsulation efficiency reached 91.20 %. The spherical particles in the PTS emulsion were dissociated and homogenous. The results of backscattered light experiments and storage stability studies showed that the PTS emulsion system prepared using CMS/XG was uniform and stable, with no obvious phase separation or emulsion droplet coalescence. With an increase in the mass ratio of XG, the water distribution in the emulsion became more evenly distributed, and the aggregation of droplets was reduced. The PTS emulsion prepared using CMS/XG improved the storage retention percentage of PTS. The cumulative release of PTS in the simulated gastric fluid was significantly lower than that in simulated intestinal fluid. The Pickering emulsion prepared using CMS/XG combinations can be used as a delivery system for functional foods and help to develop an efficient and reliable release system for hydrophobic bioactive substances.

Structural, rheological and functional properties of ultrasonic treated xanthan gums

Xanthan gum can improve the freeze-thaw stability of frozen foods. However, the high viscosity and long hydration time of xanthan gum limits its application. In this study, ultrasound was employed to reduce the viscosity of xanthan gum, and the effect of ultrasound on its physicochemical, structural, and rheological properties was investigated using High-performance size-exclusion chromatography (HPSEC), ion chromatograph, methylation analysis, 1H NMR, rheometer, etc.. The application of ultrasonic-treated xanthan gum was evaluated in frozen dough bread. Results showed that the molecular weight of xanthan gum was reduced significantly by ultrasonication (from 3.0 × 107 Da to 1.4 × 106 Da), and the monosaccharide compositions and linkage patterns of sugar residues were altered. Results revealed that ultrasonication treatment mainly broke the molecular backbone at a lower intensity, then mainly broke the side chains with increasing intensity, which significantly reduced the apparent viscosity and viscoelastic properties of xanthan gum. The results of specific volume and hardness showed that the bread containing low molecular weight xanthan gum was of better quality. Overall, this work offers a theoretical foundation for broadening the application of xanthan gum and improving its performance in frozen dough.

Effects of ultrasound time, xanthan gum, and sucrose levels on the osmosis dehydration and appearance characteristics of grapefruit slices: Process optimization using response surface methodology

In this work, the novel use of ultrasonic pre-treatment and edible coating treatment during osmosis dehydration to optimize the weight reduction, moisture loss, sucrose gain, rehydration, and surface shrinkage using a response surface methodology (RSM) based on a central composite design (CCD) technique was successfully conducted on grapefruit slices. The process parameters include sonication pre-treatment time (5-10 min), xanthan-gum-based edible coating (0.1%-0.3%, w/w), and sucrose concentration (20-50 Brix), were examined and optimized for osmosis dehydration of grapefruit slices. At each step, three grapefruit slices were immersed in an ultrasonic water bath at 40 kHz, 150 W, and 20 C. Then, the sonicated slices were placed in a container contain sucrose and xanthan, and the container was put in a 50 C water-bath for 1 h. The optimum concentration of xanthan gum, sucrose, and time of treatment were predicted to be 0.15%, 20.0 Brix, and 10.0  min, respectively. Under this optimum condition, estimated values of response variables are as follows: weight reduction 14.14%, moisture loss 25.92%, solids gain 11.78%, rehydration ratio 203.40%, and shrinkage 2.90%. The weight reduction and moisture loss increased when the sonication time and sucrose concentration increased. Results demonstrated that the experimental data could be adequately fitted into a linear model with p-value ranging from 0.0001 to 0.0309 for all the variables examined. The rehydration of dried samples increased when xanthan concentration increased. Also, the weight reduction, moisture loss, sucrose absorption, and shrinkage declined with increasing in the xanthan levels.

Novel electrospun nanofibers based on gelatin/oxidized xanthan gum containing propolis reinforced by Schiff base cross-linking for food packaging

Gelatin-based electrospun fibers are promising materials for food packaging but suffer from high hydrophilicity and weak mechanical properties. To overcome these limitations, in the current study, gelatin-based nanofibers were reinforced by using oxidized xanthan gum (OXG) as a crosslinking agent. The nanofibers' morphology was investigated through SEM, and the observations showed that the fibers' diameter was decreased by enhancing OXG content. The resultant fibers with more OXG content exhibited high tensile stress so the optimal sample obtained showed a tensile stress of 13.24 ± 0.76 MPa, which is up to 10 times more than neat gelatin fiber. Adding OXG to gelatin fibers reduced water vapor permeability, water solubility, and moisture content properties while increasing thermal stability and porosity. Additionally, the nanofibers containing propolis displayed a homogenous morphology with high antioxidant and antibacterial activities. In general, the findings suggested that the designed fibers could be used as a matrix for active food packaging.

Structure and drug delivery relationship of acidic polysaccharides: A review

Scientists from across the world are being inspired by recent development in polysaccharides and their use in medical administration. Due to their extraordinary physical, chemical, and biological characteristics, polysaccharides are excellent materials for use in medicine. Acidic polysaccharides, which include Pectin, Xanthan gum, Carrageenan, Alginate, and Glycosaminoglycan, are natural polymers with carboxyl groups that are being researched for their potential as drug delivery systems. Most publications do not discuss how the different polysaccharides interact structurally in terms of drug delivery, which limits the scope of their use. The purpose of this review is to inform readers about the structural activity correlations between acidic polysaccharides, their different modification process and effects of combination of various acidic polysaccharides which have been used in drug delivery systems and expanding their potential applications, and bringing new perspectives to the fore.

Bimetallic (Ag and MgO) nanoparticles, Aloe vera extracts loaded xanthan gum nanocomposite for enhanced antibacterial and in-vitro wound healing activity

We prepared nanocomposite (XG-AVE-Ag/MgO NCs) using the bimetallic Ag/MgO NPs, Aloe vera extract (AVE), and biopolymer (Xanthan gum (XG)) to archive a synergetic antibacterial and wound healing activity. The changes in XRD peaks at 20° of XG-AVE-Ag/MgO NCs indicated the XG encapsulation. The XG-AVE-Ag/MgO NCs showed the zeta potential and zeta size of 151.3 ± 3.14 d·nm and -15.2 ± 1.08 mV with a PDI of 0.265 while TEM showed an average size of 61.19 ± 3.89. The EDS confirmed the co-existence of Ag, Mg, carbon, oxygen, and nitrogen in NCs. XG-AVE-Ag/MgO NCs displayed higher antibacterial activity in terms of zone of inhibition, at 15.00 ± 0.12 mm for B. cereus and 14.50 ± 0.85 mm for E. coli. Moreover, NCs exhibited MICs of 2.5 μg/mL for E. coli, and 0.62 μg/mL for B. cereus. The in vitro cytotoxicity and hemolysis assays indicated the non-toxic properties of XG-AVE-Ag/MgO NCs. The higher wound closure activity was observed with the treatment of XG-AVE-Ag/MgO NCs (91.19 ± 1.87 %) compared to the control, untreated group (68.68 ± 3.54 %) at 48 h of incubation. These findings revealed that XG-AVE-Ag/MgO NCs was promising non-toxic, antibacterial, and wound-healing agent that deserved further in-vivo studies.

Resorbable membrane design: In vitro characterization of silver doped-hydroxyapatite-reinforced XG/PEI semi-IPN composite

In this study, the production and characterization of silver-doped hydroxyapatite (AgHA) reinforced Xanthan gum (XG) and Polyethyleneimine (PEI) reinforced semi-interpenetrating polymer network (IPN) biocomposite, known to be used as bone cover material for therapeutic purposes in bone tissue, were performed. XG/PEI IPN films containing 2AgHA nanoparticles were produced by simultaneous condensation and ionic gelation. Characteristics of 2AgHA-XG/PEI nanocomposite film were evaluated by structural, morphological (SEM, XRD, FT-IR, TGA, TM, and Raman) and biological activity analysis (degradation, MTT, genotoxicity, and antimicrobial activity) techniques. In the physicochemical characterization, it was determined that 2AgHA nanoparticles were homogeneously dispersed in the XG/PEI-IPN membrane at high concentration and the thermal and mechanical stability of the formed film were high. The nanocomposites showed high antibacterial activity against Acinetobacter Baumannii (A.Baumannii), Staphylococcus aureus (S.aureus), and Streptococcus mutans (S.mutans). L929 exhibited good biocompatibility for fibroblast cells and was determined to support the formation of MCC cells. It was shown that a resorbable 2AgHA-XG/PEI composite material was obtained with a high degradation rate and 64% loss of mass at the end of the 7th day. Physico-chemically developed biocompatible and biodegradable XG-2AgHA/PEI nanocomposite semi-IPN films possessed an important potential for the treatment of defects in bone tissue as an easily applicable bone cover. Besides, it was noted that 2AgHA-XG/PEI biocomposite could increase cell viability, especially in dental-bone treatments for coating, filling, and occlusion.

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.

Study on the improvement of clay properties by xanthan gum and its application on ecological slope protection engineering

Traditional substrate binder releases greenhouse gases during the production and application processes, and is detrimental to the vegetation restoration on slopes. To develop a new environmentally friendly soil substrate, this paper conducted a serial of experimental studies on the ecological function and mechanical properties of the xanthan gum (XG)-amended clay by plant growth tests and direct shear tests. The improvement mechanism of the xanthan gum (XG)-amended clay has also explored through microscopic examinations. Experimental results of plant growth tests show that the germination of ryegrass seeds and growth of seedlings can be effectively promoted by adding a proper content (≤2%) of XG into clay. Plants in substrates with 2% of XG grew best, while a high content (3-4%) of XG has an inhibitory effect on the plant growth. The results of direct shear tests illustrate that the shear strength and cohesion both increase with the increase of XG contents, while the internal friction has an opposite trend. The improve mechanism of the xanthan gum (XG)-amended clay were also explored by XRD tests and micro-scopic examinations. It is found that shows that XG does not react chemically to form new mineral components after mixing with clay. The mechanism of XG improving clay is mainly because the XG gel can fill the pores between clay particles, and enhance the cementation between clay particles. XG can enhance the mechanical properties of clay and offset the deficiencies of traditional binder. It can play an active role in the ecological slope protection project.