Highly swellable, cytocompatible and biodegradeable guar gum-based hydrogel system for controlled release of bioactive components of liquorice (Glycyrrhiza glabra L.): Synthesis and evaluation.

Glycyrrhiza glabra Linn (liquorice) has been widely used for therapeutic purposes to treat digestive disorders, immunomodulatory disorders, inflammatory disorders, diabetes, viral infections, and cancer. Liquorice contains a wide variety of bioactive compounds, including glycyrrhizin, flavonoids, and terpenoids. Several factors compromise their therapeutic efficacy, such as poor pharmacokinetic profiles and physicochemical properties. Therefore, to improve its overall effectiveness, liquorice solid dispersion (LSD) was incorporated into biopolymer-based guar gum-grafted-2-acrylamido-2-methylpropane sulfonic acid (Guar gum-g-AMPS) hydrogels designed for controlled delivery via the oral route and characterized. The qualitative analysis of LSD revealed 51 compounds. Hydrogel structural properties were assessed for their effect on swelling and release. The highest swelling ratio (6413 %) and drug release (84.12 %) occurred at pH 1.2 compared to pH 7.4 (swelling ratio of 2721 % and drug release of 79.36 %) in 48 h. The hydrogels exhibited high porosity (84.23 %) and biodegradation (9.30 % in 7 days). In vitro hemolysis tests have demonstrated the compatibility of the hydrogel with blood. CCK-8 assay confirmed the biocompatibility of the synthesized hydrogel using osteoblasts and RIN-m5f cells. LSD exhibited good anti-inflammatory activity when loaded into hydrogels after being subjected to protein denaturation experiments. Moreover, LSD-loaded hydrogels have good antioxidant and antibacterial properties.

Development and characterization of polyethylene oxide and guar gum-based hydrogel; a detailed in-vitro analysis of degradation and drug release kinetics.

Herein, we synthesized hydrogel films from crosslinked polyethylene oxide (PEO) and guar gum (GG) which can offer hydrophilicity, antibacterial efficacy, and neovascularization. This study focuses on synthesis and material/biological characterization of rosemary (RM) and citric acid (CA) loaded PEO/GG hydrogel films. Scanning Electron Microscopy images confirmed the porous structure of the developed hydrogel film matrix (PEO/GG) and the dispersion of RM and CA within it. This porous structure promotes moisture adsorption, cell attachment, proliferation, and tissue layer formation. Fourier Transform Infrared Spectroscopy (FTIR) further validated the crosslinking of the PEO/GG matrix, as confirmed by the appearance of C-O-C linkage in the FTIR spectrum. PEO/GG and PEO/GG/RM/CA revealed similar degradation and release kinetics in Dulbecco's Modified Eagle Medium, Simulated Body Fluid, and Phosphate Buffer Saline (degradation of ∼55 % and release of ∼60 % RM in 168 h.). The developed hydrogel film exhibited a zone of inhibition against Escherichia. coli (2 mm) and Staphylococcus. aureus (9 mm), which can be attributed to the presence of RM in the hydrogel film. Furthermore, incorporating CA in the hydrogel film promoted neovascularization, as confirmed by the Chorioallantoic Membrane Assay. The developed RM and CA-loaded PEO/GG-based hydrogel films offered suitable in-vitro properties that may aid in potential wound healing applications.

An arabinogalactan isolated from Cynanchum atratum promotes lymphangiogenesis and lymphatic vessel remodeling to alleviate secondary lymphedema.

Secondary lymphedema is a chronic and incurable disease lacking satisfactory therapeutic drugs. It primarily results from lymphatic vessel dysfunction resulting from factors such as tumor-related surgery, injury, or infection. Promoting lymphangiogenesis and lymphatic vessel remodeling is crucial for restoring tissue fluid drainage and treating secondary lymphedema. In this study, we discovered that the oral administration of a type-II arabinogalactan (CAPW-1, molecular weight: 64 kDa) significantly promoted lymphangiogenesis and alleviated edema in mice with secondary lymphedema. Notably, the tail diameter of the CAPW-1200 group considerably decreased in comparison to that of the lymphedema group, with an average diameter difference reaching 0.98 mm on day 14. CAPW-1 treatment also reduced the average thickness of the subcutaneous area in the CAPW-1200 group to 0.37 mm (compared with 0.73 mm in the lymphedema group). It also facilitated the return of injected indocyanine green (ICG) from the tail tip to the sciatic lymph nodes, indicating that CAPW-1 promoted lymphatic vessel remodeling at the injury site. In addition, CAPW-1 enhanced the proliferation and migration of lymphatic endothelial cells. This phenomenon was associated with the activation of the toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway, thereby promoting the expression of vascular endothelial growth factor-C (VEGF-C), which can be abolished using a TLR4 antagonist. Despite these findings, CAPW-1 did not alleviate the symptoms of lymphedema or restore lymphatic drainage in VEGFR3flox/flox/Prox1-CreERT2 mice. In summary, CAPW-1 alleviates secondary lymphedema by promoting lymphangiogenesis and lymphatic vessel remodeling through the activation of the TLR4/NF-κB/VEGF-C signaling pathway, indicating its potential as a therapeutic lymphangiogenesis agent for patients with secondary lymphedema.

Synergistic effect of gellan gum and guar gum on improving the foaming properties of soy protein isolate-based complexes: Interaction mechanism and interfacial behavior.

Interactions among multi-component play a critical role in modulating the foaming properties of aerated foods. This study evaluated the mechanisms of synergistic improvement of gellan gum (GEG) and guar gum (GUG) on the foaming properties of soy protein isolate (SPI)-based complex. The results showed that the GEG/GUG ratio was closely related to the intermolecular interactions of SPI-based ternary complex and the dynamical changing of its foaming properties. The SPI/GEG/GUG ternary complex with a GEG/GUG ratio of 2/3 exhibited the highest foamability (195 %) and comparable foam stability (99.17 %), which were 32.95 % and 2.99 % higher than that of SPI/GEG binary complex. At this ratio, GUG promoted the interactions between SPI and GEG, and bound to complex's surface through hydrogen bonding, resulting in the increase of particle size and surface charge, and the decrease of surface hydrophobicity. Although this reduced the diffusion of complex onto the air/water interface, it increased permeation rate and molecular rearrangement behavior, which were the potential mechanisms to improve the foaming properties. Additionally, the synergistic effect of GEG and GUG also enhanced the elastic strength and solid characteristics of foam systems. This study provided a theoretical guidance for the targeted modulation of foaming properties of multi-component aerated foods.

Influence of 3-chloropropyl) triethoxysilane and pH on the properties of modified guar gum film.

Guar gum (GG) as a polymer biopolymer is widely used in the field of bio-based packaging. However, its poor mechanical properties, barrier properties and high viscosity greatly hinder its use as an effective packaging material. Therefore, this study introduced CPTES to improve the mechanical (16.58-27.39 MPa) and tensile properties (26.80 %-30.67 %). The FTIR and XRD results indicated a strong interaction between the biofilm fractions modified by CPTES, CPTES bound to the hydroxyl groups on GG and formed a dense polysiloxane network through adsorption and grafting. OM and AFM reflect a denser and flatter film structure on the surface of the G30 film, which has the best film formation. Based on this, the pH of the solution was further adjusted to reach an alkaline environment, disrupting the intermolecular binding through electrostatic repulsion. The rheological behavior indicates that the viscosity and viscoelasticity of film solution gradually decrease with the increase in pH. OM and AFM results show that the G30/8 film has the best compact properties, while the nonporous compact film structure further improves the mechanical, barrierand and thermodynamic properties of the film. Accordingly, the findings of this study had a certain value for regulating the low viscoelasticity of GG emulsion and enhancing the stability of film formation.

ß(1,3) ß(1,6) glucogalactan from Rhizopus microsporus var. oligosporus: extraction, characterization, antioxidant and α-amylase inhibitory activities.

In this study, the Box-Behnken experimental planning was used to optimize the extraction of polysaccharides from the cell wall of Rhizopus microspore var. oligosporus, with analysis of the quantitative effects of parameters pH, temperature and extraction time for polysaccharide yield. The optimal conditions for extraction were determined by the regression equation and evaluation of the response surface graphs, which indicated: pH 13, temperature of 120ºC and time of 60 min, with maximum yield around 18.5%. Fourier transform infrared spectroscopy analysis indicated typical polysaccharide signals. Nuclear magnetic resonance spectroscopy and monosaccharide analysis indicated a ß(1,3) ß(1,6) glucogalactan. The polysaccharide exhibited an average molecular weight of 120 kDa and a polymerization degree of 741. Antioxidant assays in vitro revealed the potential of polysaccharide in elimination of ABTS+ radical and hydroxyl radicals. EC50 values for free radical elimination were 7.69 and 17.8 mg/mL, for ABTS+ and hydroxyls, respectively. The polysaccharides showed potential for α-amylase inhibition with an EC50 of 1.66 mg/mL. The results suggest that ß(1,3) ß(1,6) glucogalactan from Rhizopus microsporus var. oligosporus can be used in biotechnological applications.

Optimized production and characterization of endo-ß-mannanase by Aspergillus niger for generation of prebiotic mannooligosaccharides from guar gum.

Optimized production of Aspergillus niger ATCC 26011 endo-ß-mannanase (ManAn) on copra meal resulted in 2.46-fold increase (10,028 U/gds). Purified ManAn (47 kDa) showed high affinity towards guar gum (GG) as compared to konjac gum and locust bean gum with Km 2.67, 3.25 and 4.07 mg/mL, respectively. ManAn efficiently hydrolyzed GG and liberated mannooligosaccharides (MOS). Changes occurring in the rheological and compositional aspects of GG studied using Differential scanning calorimetry (DSC), Thermal gravimetric analysis (TGA) and X-ray diffraction (XRD) revealed increased thermal stability and crystallinity of the partially hydrolyzed guar gum (PHGG). Parametric optimization of the time and temperature dependent hydrolysis of GG (1% w/v) with 100 U/mL of ManAn at 60 °C and pH: 5.0 resulted in 12.126 mg/mL of mannotetraose (M4) in 5 min. Enhanced growth of probiotics Lactobacilli and production of short chain fatty acids (SCFA) that inhibited enteropathogens, confirmed the prebiotic potential of PHGG and M4.

The study of galactomannans with different molecular weights and their ability to form microparticles suitable for pulmonary delivery.

The influence of locust bean gum (LBG) galactomannans (GMs) molecular weight (Mw) to assemble microparticulate systems was evaluated, and carriers for deep lung delivery were developed. A commercial batch of LBG with a mannose/galactose (M/G) ratio of 2.4 (batch 1) was used to study the influence of different microwave partial acid hydrolysis conditions on carbohydrate composition, glycosidic linkages, and aqueous solutions viscosity. The microwave treatment did not affect the composition, presenting 4-Man (36-42 %), 4,6-Man (27-35 %), and T-Gal (24-25 %) as the main glycosidic linkages. Depolymerization led to a viscosity reduction (≤0.005 Pa·s) with no major impact on polysaccharide debranching. The structural composition of the LBG galactomannans were further elucidated with sequence-specific proteins using carbohydrate microarray technologies. A second batch of LBG (M/G 3.3) was used to study the impact of GMs with different Mw on microparticle assembling, characteristics, and insulin release kinetics. The low-Mw GMs microparticles led to a faster release (20 min) than the higher-Mw (40 min) ones, impacting the release kinetics. All microparticles exhibited a safety profile to cells of the respiratory tract. However, only the higher-Mw GMs allowed the assembly of microparticles with sizes suitable for this type of administration.

Fermenter scale production of recombinant beta-mannanase by E. coli BL21 cells under microaerobic environment.

Aim of the study was to optimize and produce beta-mannanase at fermenter scale by using cheaper minimal media. Increased production of beta-mannanase from Microbacterium camelliasinensis CIAB417 was achieved by heterologous expression in E. coli BL21 (DE3). The scale-up production of beta-mannanase was optimized from shake flask to 5-L fermenter. The cost-effective minimal media (M9+e) without any vitamins was found to be most effective and optimized for culturing the cells. The same media displayed no significant fluctuation in the pH while culturing the cells for the production of beta-mannanase both at shake flask and fermenter level. Additionally, E. coli cells were able to produce similar amount of dry cell weight and recombinant beta-mannanase both in the presence of micro and macro-oxygen environment. The optimized media was demonstrated to show no significant drop in pH throughout the recombinant protein production process. In one litre medium, 2.0314 g dry weight of E. coli cells yielded 1.8 g of purified recombinant beta-mannanase. The purified enzyme was lyophilized and demonstrated to hydrolyse locust bean gum to release mannooligosaccharides.

Self-Healing Guar Gum-Based Nanocomposite Hydrogel Promotes Infected Wound Healing through Photothermal Antibacterial Therapy.

Preventing bacterial infections is a crucial aspect of wound healing. There is an urgent need for multifunctional biomaterials without antibiotics to promote wound healing. In this study, we fabricated a guar gum (GG)-based nanocomposite hydrogel, termed GBTF, which exhibited photothermal antibacterial therapy for infected wound healing. The GBTF hydrogel formed a cross-linked network through dynamic borate/diol interactions between GG and borax, thereby exhibiting simultaneously self-healing, adaptable, and injectable properties. Additionally, tannic acid (TA)/Fe3+ nanocomplexes (NCs) were incorporated into the hydrogel to confer photothermal antibacterial properties. Under the irradiation of an 808 nm near-infrared laser, the TA/Fe3+ NCs in the hydrogel could rapidly generate heat, leading to the disruption of bacterial cell membranes and subsequent bacterial eradication. Furthermore, the hydrogels exhibited good cytocompatibility and hemocompatibility, making them a precandidate for preclinical and clinical applications. Finally, they could significantly promote bacteria-infected wound healing by reducing bacterial viability, accelerating collagen deposition, and promoting epithelial remodeling. Therefore, the multifunctional GBTF hydrogel, which was composed entirely of natural substances including guar gum, borax, and polyphenol/ferric ion NCs, showed great potential for regenerating infected skin wounds in clinical applications.

Shellac and locust bean gum coacervated curcumin, epigallocatechin gallate nanoparticle ameliorates diabetic nephropathy in a streptozotocin-induced mouse model.

Curcumin and epigallocatechin gallate have the disadvantage of low aqueous solubility and first-pass metabolism, resulting in limited bioavailability. This work aimed to enhance oral bioavailability by forming gastric pH-stable shellac nanoparticles containing curcumin and epigallocatechin gallate using locust bean gum by anti-solvent precipitation (CESL-NP). The nanoparticles were characterized by their particle size, morphology, zeta potential, gastric pH stability, release profile, drug loading, and entrapment efficiency. The findings showed that a network of hydrolyzed shellac, locust bean gum, curcumin, and epigallocatechin gallate successfully entrapped individual particles inside a complex system. The morphological investigation of the CESL-NP formulation using FESEM, TEM, and AFM revealed the presence of spherical particles. FTIR, DSC, and XRD analysis revealed that curcumin and epigallocatechin gallate were amorphous due to their bond interactions with the matrix. Streptozotocin-treated mice, upon treatment with CESL-NP, showed kidney and pancreatic improvements with normalized kidney hypertrophy index and histopathology, maintained biochemical parameters, increased beta cell count, and a 38.68-fold higher blood glucose level inhibition were observed when compared to free-(CUR + EGCG). This research affirms that the shellac-locust bean gum complex shows potential for the sustained oral delivery of curcumin and epigallocatechin gallate, specifically for treating diabetic nephropathy.

Synthesis and characterization of amino-functionalized guar gum based polyurea: Preparation of iodine complexes, structural investigation and release studies.

Biobased materials are expanding dramatically in various industrial applications due to their unique intrinsic properties. In this study, various chemical functionalization procedures were used to synthesize guar gum, a naturally occurring polysaccharide-based polyurea, and its iodine complexes. Firstly, guar gum was subjected to tosylation reaction using p-toluene sulphonyl chloride to introduce tosyl moieties in the polymer chain with the degree of substitution (DS) ranging between 0.16 and 1.54. Sample having the highest degree of tosyl moiety was further reacted with tris(2-aminoethyl) amine to produce 6-deoxy-6-tris(2-aminoethyl) amine derivative via nucleophilic substitution reaction to impart amino functional groups. The degree of substitution in 6-deoxy-6-tris(2-aminoethyl) amine derivative was found to be 0.59. 6-deoxy-6-tris(2-aminoethyl) amine derivative was reacted with different diisocyanates (Toluene-2,4-diisocyanate (TDI), 1,6-diisocyanatohexane (HMDI)) to produce guar gum based polyurea. Iodine complexes of the resulting polyurea were prepared by reacting with different iodinating agents. Different chemical reactions, formation of polyurea and its iodine complexes were thoroughly analyzed by different analytical techniques such as FT-IR, NMR, elemental analysis, XRD, UV-Vis spectroscopy, and a reaction scheme has been proposed. Morphological and rheological characteristics were analyzed by SEM and viscosity measurement. Thermal analysis was carried out by TGA and DSC studies. Finally, by examining the complex's UV-Vis spectra, the iodine release characteristics from polyurea­iodine complexes were investigated.

Development and evaluation of guar gum-coated nano-nutriosomes for cyanidin-3-O-glucoside encapsulation.

Cyanidin-3-O-glucoside (C3G) is a type of water-soluble flavonoid compound that is abundantly found in fruits and vegetables. C3G possesses numerous biological activities, however, it is prone to breakdown under environmental conditions. To overcome these issues, we developed nano-nutriosome (NS) carriers created by vortex-mixing and probe-sonication techniques for C3G encapsulation in which the phospholipid and Nutriose® FB06 were chosen as carrier material, and guar gum (GG) as a coating material to formulate a unilamellar and multicompartment structure. This study aimed to develop and evaluate C3G-loaded nano-nutriosomes coated by GG (GG-C3G-NS) for improving physicochemical stability, antioxidant activity, cellular uptake, and controlled release properties. The C3G-NS and GG-C3G-NS are nanosized (143.47 to 154.13 nm), with high encapsulation efficiency (>93.31 %). The NS carriers successfully encapsulated C3G which was confirmed by transmission electron microscopy, differential scanning calorimetry, and Fourier transform infrared spectroscopy. C3G showed more stability in storage, thermal, pH, ionic, and oxidative conditions. Furthermore, the NS exhibited a better-controlled release of C3G in different food stimulant conditions and in vitro release study. Additionally, NS systems enhanced cellular uptake and showed no cytotoxicity. Overall, GG-NS could be a promising nanocarrier for improving the stability, controlled release, and antioxidant activity of bioactive compounds.

The α-linkage in funoran and agarose could be hydrolyzed by a GH96 family enzyme: Discovery of the α-funoranase.

Agarans represent a group of galactans extracted from red algae. Funoran and agarose are the two major types and commercially applied polysaccharides of agaran. Although the glycoside hydrolases targeting ß-glycosidic bonds of agaran have been widely investigated, those capable of degrading α-glycosidic bonds of agarose were limited, and the enzyme degrading α-linkages of funoran has not been reported till now. In this study, a GH96 family enzyme BiAF96A_Aq from a marine bacterium Aquimarina sp. AD1 was heterologously expressed in Escherichia coli. BiAF96A_Aq exhibited dual activities towards the characteristic structure of funoran and agarose, underscoring the multifunctionality of GH96 family members. Glycomics and NMR analysis revealed that BiAF96A_Aq hydrolyzed the α-1,3 glycosidic bonds between 3,6-anhydro-α-l-galactopyranose (LA) and ß-d-galactopyranose-6-sulfate (G6S) of funoran, as well as LA and ß-d-galactopyranose (G) of agarose, through an endo-acting manner. The end products of BiAF96A_Aq were majorly composed of disaccharides and tetrasaccharides. The identification of the activity of BiAF96A_Aq on funoran indicated the first discovery of the funoran hydrolase for α-1,3 linkage. Considering the novel catalytic reaction, we proposed to name this activity as "α-funoranase" and recommended the assignment of a dedicated EC number for its classification.

A multifunctional Ag NPs/guar gum hydrogel as versatile platform for catalysts, antibacterial agents, and construction of oil-water separation interfaces.

The frequently encountered wastewater contaminations, including soluble aromatic compound and dye pollutants, pathogenic bacteria, and insoluble oils, have resulted in significant environmental and human health issues. It poses a challenge to utilize identical materials for the treatment of complex wastewater. Herein, in this research, multifunctional Ag NPs/guar gum hybrid hydrogels were fabricated using a facile in situ reduction and self-crosslinking method for efficient remediation of complex wastewater. The Ag NPs/guar gum hybrid hydrogel showed remarkable remodeling, adhesive, and self-healing characteristics, which was favorable for its versatile applications. The combination of Ag NPs with the guar gum skeleton endowed the hybrid hydrogel with exceptional catalytic activity for reducing aromatic compounds and dye pollutants, as well as remarkable antibacterial efficacy against pathogenic bacteria. In addition, the Ag NPs/guar gum hybrid hydrogel could be employed to coat a variety of substrates, including cotton fabrics and stainless steel meshes. The hydrogel coated cotton fabrics and meshes presented superhydrophilicity/underwater superoleophobicity, excellent antifouling capacity, and outstanding recyclability, which could be successfully applied for efficient separation of oil-water mixtures. The findings of this work provide a feasible and cost-effective approach for the remediation of intricate wastewater.

Superabsorbent quaternary ammonium guar gum hydrogel with controlled release of humic acid for soil improvement and plant growth.

Growing plants in karst areas tends to be difficult due to the easy loss of water and soil. To enhance soil agglomeration, water retention, and soil fertility, this study developed a physically and chemically crosslinked hydrogel prepared from quaternary ammonium guar gum and humic acid. The results showed that non-covalent dynamic bonds between the two components delayed humic acid release into the soil, with a release rate of only 35 % after 240 h. The presence of four hydrophilic groups (quaternary ammonium, hydroxyl, carboxyl, and carbonyl) in the hydrogel more than doubled the soil's water retention capacity. The interaction between hydrogel and soil minerals (especially carbonate and silica) promoted hydrogel-soil and soil­carbonate adhesion, and the adhesion strength between soil particles was enhanced by 650 %. Moreover, compared with direct fertilization, this degradable hydrogel not only increased the germination rate (100 %) and growth status of mung beans but also reduced the negative effects of excessive fertilization on plant roots. The study provides an eco-friendly, low-cost, and intelligent system for soil improvement in karst areas. It further proves the considerable application potential of hydrogels in agriculture.

Optimization of guar gum-based anti-browning coating for prolonging the shelf life of cut potatoes.

The impact of guar gum (GG), crude algae ethanolic extract (CAEE), and turmeric essential oil (TEO) incorporated edible coating formulations on the quality of cut potatoes was investigated at room temperature (27 ±â€¯3 °C, 70-85 % RH) storage using a rotatable central composite design. Besides, 30 % glycerol, 5 % calcium chloride, and 3 % ascorbic acid (w/w) were added to the coating solution as additives. The surface color, respiration rate, water vapor transmission rate, visible mold growth, and sensory analysis were assessed after seven days of storage. The inclusion of ascorbic acid and TEO in edible coating demonstrated a more effective delay in browning. The coated potatoes had lower OTR, CTR, and WVTR values for GG concentrations of 0.5 to 1 g/100 mL than the control. Compared to additives, higher concentrations of GG improved response parameters. The WVTR value of coated potatoes was significantly impacted by the interaction between CAEE and TEO with GG. Incorporating CAEE and TEO into the formulations of guar gum led to a reduction in the permeability of the coating to oxygen and water vapor. The seven days of extended shelf life compared to two days of control were observed with the optimized coating formulation. Furthermore, the application of the coating treatment proved effective in preventing enzymatic browning and creating a barrier against moisture and gases, contributing to prolonged freshness during extended storage periods.

In-depth understanding of transport behavior of sulfided nano zerovalent iron/reduced graphene oxide@guar gum slurry: Stability and mobility.

Nanoscale zero-valent iron (NZVI), which has the advantages of small particle size, large specific surface area, and high reactivity, is often injected into contaminated aquifers in the form of slurry. However, the prone to passivation and agglomeration as well as poor stability and mobility of NZVI limit the further application of this technology in fields. Therefore, sulfided NZVI loaded on reduced graphene oxide (S-NZVI/rGO) and guar gum (GG) with shear-thinning properties as stabilizers were used to synthesize S-NZVI/rGO@GG slurries. SEM, TEM, and FT-IR confirmed that the dispersion and anti-passivation of NZVI were optimized in the coupled system. The stability and mobility of the slurry were improved by increasing the GG concentration, enhancing the pH, and decreasing the ionic strength and the presence of Ca2+ ions, respectively. A modified advection-dispersion equation (ADE) was used to simulate the transport experiments considering the strain and physicochemical deposition/release. Meanwhile, colloidal filtration theory (CFT) demonstrated that Brownian motion plays a dominant role in the migration of S-NZVI/rGO@GG slurry, and the maximum migration distance can be increased by appropriately increasing the injection rate. Extended-Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory showed that the excellent stability and migration of S-NZVI/rGO@GG slurry mainly came from the GG spatial forces. This study has important implications for the field injection of S-NZVI/rGO@GG slurry. According to the injection parameters, the injection range of S-NZVI/rGO@GG slurry is effectively controlled, which lays the foundation for the promotion of application in actual fields.

Design of Stretchable and Conductive Self-Adhesive Hydrogels as Flexible Sensors by Guar-Gum-Enabled Dynamic Interactions.

The limited elasticity and inadequate bonding of hydrogels made from guar gum (GG) significantly hinder their widespread implementation in personalized wearable flexible electronics. In this study, we devise GG-based self-adhesive hydrogels by creating an interpenetrating network of GG cross-linked with acrylic, 4-vinylphenylboronic acid, and Ca2+. With the leverage of the dynamic interactions (hydrogen bonds, borate ester bonds, and coordination bonds) between -OH in GG and monomers, the hydrogel exhibits a high stretchability of 700%, superior mechanical stress of 110 kPa, and robust adherence to several substrates. The adhesion strength of 54 kPa on porcine skin is obtained. Furthermore, the self-adhesive hydrogel possesses stable conductivity, an elevated gauge factor (GF), and commendable durability. It can be affixed to the human body as a strain sensor to obtain precise monitoring of human movement behavior. Our research offers possibilities for the development of GG-based hydrogels and applications in wearable electronics and medical monitoring.

Understanding the mechanism of high viscosity food delaying gastric emptying.

Controlling the structure and viscosity of food can influence the development of diet-related diseases. Food viscosity has been linked with health through its impact on human digestion and gastrointestinal transit, however, there is limited understanding of how the viscosity of food regulates gastric emptying. Here, we used model food preparations with different viscosities using guar gum, to explore the mechanism underlying the influence of viscosity on gastric motility, gastric emptying and postprandial blood glucose. Based on experiments in human volunteers and animals, we demonstrated that high viscosity meals increased gastric antrum area and gastric retention rate. Viscosity also affected gut hormone secretion, reduced the gene expression level of interstitial cells of Cajal, resulting in a delay of gastric emptying and limiting the increase in postprandial glucose. This improved mechanistic understanding of food viscosity during gastric digestion is important for designing new foods to benefit human health.