Guar gum and its composites as potential materials for diverse applications: A review

Construction of a double-responsive modified guar gum nanoparticles and its application in oral insulin administration

The use of intelligent insulin delivery systems has become more important for treating diabetes. In this study, a dual-responsive oral insulin delivery nanocarrier that responds to glucose and pH has been developed. First, the oleic acid hydrophobic modified guar gum (GG) was synthesized by the esterification reaction, and the γ-polyglutamic acid (γ-PGA) was coupled with GG by the amidation reaction. The obtained pH-responsive copolymer (γ-PGA-GG) was cross-linked by concanavalin A to obtain pH/glucose dual-responsive nanocarriers, and insulin was effectively loaded into the dual-responsive nanocarriers. The insulin-loaded nanoparticles can achieve effective pH and glucose responses, releasing insulin on demand. In vitro and in vivo studies demonstrated the dual-responsive nanoparticles can protect insulin against the pH changes in the digestive tract and deliver insulin into the body to exert a hypoglycemic effect. Moreover, the dual-responsive nanoparticles have significant potential to be employed for oral insulin delivery.

Efficient liquid phase confiscation of nile blue using a novel hybrid nanocomposite synthesized from guar gum-polyacrylamide and erbium oxide

In recent times, biopolymer-metal oxide nanocomposites have gained prominent importance in the attenuation of environmental toxicants from aqueous phase. But lanthanide oxide-based biopolymer nanocomposites have scantly been evaluated for their adsorption potential. A novel guar gum-polyacrylamide/erbium oxide nanocomposite (GG-PAAm/Er₂O₃ NC) adsorbent was synthesized by copolymerization of guar gum (GG) and acrylamide (AAm) utilizing N-N′-methylenebisacrylamide as a crosslinker and Er₂O₃ as a reinforcing agent. The adsorptive efficacy of GG-PAAm/Er₂O₃ nanocomposite was evaluated using nile blue (NB) as a model pollutant dye from aquatic system. The prepared adsorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, Brunauer–Emmett–Teller (BET) analysis, thermogravimetric analysis, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM–EDX), and high-resolution transmission electron microscopy (HRTEM). The optimal process parameters, which include dosage (0.8 g/L), agitation time (40 min), initial solution pH (6), and initial NB concentration (80 mg/L) were determined by batch methodology. The equilibrium data for NB confiscation was better expressed by Langmuir isotherm model, with maximal adsorption effectiveness (Q_m) of 225.88 mg NB/g demonstrating the actively monolayer adsorption onto homogeneous surface of GG-PAAm/Er₂O₃ NC. The kinetics of NB sorption process onto GG-PAAm/Er₂O₃ NC was reliable with pseudo-second order model. Thermodynamic parameters such as ΔH^° (15–17 kJ/mol) and ΔS^° (0.079–0.087 kJ/mol/K), and − ΔG^° (8.81–10.55 kJ/mol) for NB validated the endothermic, an increased randomness at the GG-PAAm/Er₂O₃–NB interface, and spontaneity and feasibility of the process, respectively. The spent nanocomposite was effectively regenerated with NaOH, and could be reused proficiently for five runs demonstrating the high reusability potential of the nanocomposite. The commendable removal efficiency and high reusability of GG-PAAm/Er₂O₃ NC recommended it to be a highly competent adsorbent for cationic dyes particularly NB diminution from aqueous waste.

Plant Polysaccharides in Engineered Pharmaceutical Gels

Hydrogels are a great ally in the pharmaceutical and biomedical areas. They have a three-dimensional polymeric structure that allows the swelling of aqueous fluids, acting as an absorbent, or encapsulating bioactive agents for controlled drug release. Interestingly, plants are a source of biogels, specifically polysaccharides, composed of sugar monomers. The crosslinking of these polymeric chains forms an architecture similar to the extracellular matrix, enhancing the biocompatibility of such materials. Moreover, the rich hydroxyl monomers promote a hydrophilic behavior for these plant-derived polysaccharide gels, enabling their biodegradability and antimicrobial effects. From an economic point of view, such biogels help the circular economy, as a green material can be obtained with a low cost of production. As regards the bio aspect, it is astonishingly attractive since the raw materials (polysaccharides from plants-cellulose, hemicelluloses, lignin, inulin, pectin, starch, guar, and cashew gums, etc.) might be produced sustainably. Such properties make viable the applications of these biogels in contact with the human body, especially incorporating drugs for controlled release. In this context, this review describes some sources of plant-derived polysaccharide gels, their biological function, main methods for extraction, remarkable applications, and properties in the health field.

Optimization of dyes and toxic metals removal from environmental water samples by clinoptilolite zeolite using response surface methodology approach

The present study aimed to remove crystal violet (CV), malachite green (MG), Cd(II), and Pb(II) from an aqueous solution using clinoptilolite zeolite (CZ) as an adsorbent. Response surface methodology (RSM) based on central composite design (CCD) was used to analyze and optimize the process parameters, such as pH, analyte concentration, adsorbent amount, and sonication time. Quadratic models with the coefficient of determination (R2) of 0.99 (p < 0.0001) were compared statistically. The results revealed that the selected models have good precision and a good agreement between the predicted and experimental data. The maximum removal of contaminants was achieved under optimum conditions of pH = 6, sonication time of 22 min, the adsorbent amount of 0.19 g, and analyte concentration of 10 mg L-1. The reusability test of the adsorbent showed that the CZ adsorbent could be used 5 times in water and wastewater treatment processes. According to the results of interference studies, the presence of different ions, even at high concentrations, does not interfere with the removal of contaminants. Applying the CZ adsorbent on environmental water samples revealed that CZ adsorbent could remove CV, MG, Cd(II), and Pb(II) in the range of 84.54% to 99.38% and contaminants present in industrial effluents. As a result, the optimized method in this study can be widely used with high efficiency for removing CV, MG, Cd(II), and Pb(II) from water and wastewater samples.

Synthesis and Rheological Characterization of a Novel Salecan Hydrogel

Salecan (Sal) is a novel microbial polysaccharide. In the present research, thermal treatment was performed to fabricate Sal hydrogel. The effect of Sal concentration on water holding capacity, swelling properties, texture properties, and microstructure of the hydrogels was discussed. It was found that the equilibrium degree of swelling (EDS) of Sal hydrogels was above 1500%, inferred Sal was a highly hydrophilic polysaccharide. As Sal concentration increased from 3.5 to 8.0 wt%, the hardness increased from 0.88 to 2.07 N and the water hold capability (WHC) increased from 91.3% to 98.2%. Furthermore, the internal network structure of Sal hydrogel also became denser and more uniform. Rheological studies suggested that elastic hydrogel formed under the gelation process. All these results demonstrated that Sal hydrogel prepared by thermal treatment had good gelling properties, which opened up a new safe way for the preparation of Sal hydrogel and broadened the application range of Sal.

In silico Identification of miRNAs and Their Targets in Cluster Bean for Their Role in Development and Physiological Responses

Cluster bean popularly known as “guar” is a drought-tolerant, annual legume that has recently emerged as an economically important crop, owing to its high protein and gum content. The guar gum has wide range of applications in food, pharma, and mining industries. India is the leading exporter of various cluster bean-based products all across the globe. Non-coding RNAs (miRNAs) are involved in regulating the expression of the target genes leading to variations in the associated pathways or final protein concentrations. The understanding of miRNAs and their associated targets in cluster bean is yet to be used to its full potential. In the present study, cluster bean EST (Expressed Sequence Tags) database was exploited to identify the miRNA and their predicted targets associated with metabolic and biological processes especially response to diverse biotic and abiotic stimuli using in silico approach. Computational analysis based on cluster bean ESTs led to the identification of 57 miRNAs along with their targets. To the best of our knowledge, this is the first report on identification of miRNAs and their targets using ESTs in cluster bean. The miRNA related to gum metabolism was also identified. Most abundant miRNA families predicted in our study were miR156, miR172, and miR2606. The length of most of the mature miRNAs was found to be 21nt long and the range of minimal folding energy (MFE) was 5.8–177.3 (−kcal/mol) with an average value of 25.4 (−kcal/mol). The identification of cluster bean miRNAs and their targets is predicted to hasten the miRNA discovery, resulting in better knowledge of the role of miRNAs in cluster bean development, physiology, and stress responses.

Hemocompatibility of Galactomannan and Galactoglucomannan Sulfates in In Vitro Experiments

We identified compounds that do not independently provoke aggregation of human platelets and do not affect hemolysis of human erythrocytes in vitro: lacking anticoagulant activity sulfated galactoglucomannan (polydispersity 1.43; degree of sulfation 0.66) in concentrations ≤0.2 mg/ml; exhibiting anticoagulant activity (in concentrations up to 0.002 mg/ml) sulfated galactoglucomannan (polydispersity 1.5; degree of sulfation 1.81) and galactomannan obtained by sulfation with the sulfamic acid-urea complex (polydispersity 2.75; degree of sulfation 1.25) and galactomannans obtained by sulfation with chlorosulfonic acid in 1,4-dioxane (polydispersity 1.61/22.27; degree of sulfation 1.00/0.74).

Development of Bigels Based on Date Palm-Derived Cellulose Nanocrystal-Reinforced Guar Gum Hydrogel and Sesame Oil/Candelilla Wax Oleogel as Delivery Vehicles for Moxifloxacin

Bigels are biphasic semisolid systems that have been explored as delivery vehicles in the food and pharmaceutical industries. These formulations are highly stable and have a longer shelf-life than emulsions. Similarly, cellulose-based hydrogels are considered to be ideal for these formulations due to their biocompatibility and flexibility to mold into various shapes. Accordingly, in the present study, the properties of an optimized guar gum hydrogel and sesame oil/candelilla wax oleogel-based bigel were tailored using date palm-derived cellulose nanocrystals (dp-CNC). These bigels were then explored as carriers for the bioactive molecule moxifloxacin hydrochloride (MH). The preparation of the bigels was achieved by mixing guar gum hydrogel and sesame oil/candelilla wax oleogel. Polarizing microscopy suggested the formation of the hydrogel-in-oleogel type of bigels. An alteration in the dp-CNC content affected the size distribution of the hydrogel phase within the oleogel phase. The colorimetry studies revealed the yellowish-white color of the samples. There were no significant changes in the FTIR functional group positions even after the addition of dp-CNC. In general, the incorporation of dp-CNC resulted in a decrease in the impedance values, except BG3 that had 15 mg dp-CNC in 20 g bigel. The BG3 formulation showed the highest firmness and fluidity. The release of MH from the bigels was quasi-Fickian diffusion mediated. BG3 showed the highest release of the drug. In summary, dp-CNC can be used as a novel reinforcing agent for bigels.

An efficient biosynthesis of palladium nanoparticles using Bael gum and evaluation of their catalytic and antibacterial activity

We report a facile microwave-assisted synthesis of palladium nanoparticles (PdNPs) using Bael gum (BG) and it's carboxymethylated (CMBG) derivative. The prepared nanoparticles (BG@PdNPs and CMBG@PdNPs) were evaluated for antibacterial and catalytic activity in the reduction of organic dye pollutants. The developed synthetic method is simple, low cost and eco-friendly, wherein the process requires no additional reducing or capping agents. The CMBG was prepared via etherification reaction between BG and monochloroacetic acid using Williamson synthesis method. The PdNPs were synthesized using BG and CMBG as stabilizers and reducing agents. The PdNPs were found to be well dispersed spherical, with the crystalline size of the order of 7-21 nm. The results showed that the CMBG@PdNPs were smaller in size (7 ± 2 nm) than those capped with BG@PdNPs (10 ± 2 nm). The catalytic ability of CMBG@PdNPs was examined for the reduction of Methyl Orange (MO), Methyl Red(MR), and Rhodamine-B (RhB) in the presence of NaBH₄. The results showed that CMBG@PdNPs exhibited a higher catalytic ability than BG@PdNPs. Moreover, it was found that CMBG@PdNPs served several times as a retrievable and reusable catalyst which is stable even after six cycles of reaction. The CMBG@PdNPs and BG@PdNPs showed excellent antibacterial activity. The results indicate that CMBG@PdNPs have greater potential application as a catalyst in the reduction of organic pollutants and antibacterial activity.

Biomineralisation to Increase Earth Infrastructure Resilience

The vulnerability of buildings and structures to rain and flooding due to a lack of adaptive capacity is an issue all over the world. Exploring the bio-resources availability and engineering performance is crucial to increase infrastructure’s resilience. The current study analyses earth-based mortars using mineral precipitation as a biostabiliser (bio) and compares their performance with cement-based mortars. Cultures of S. oneidensis with a concentration of 2.3 × 10⁸ cfu/mL were used to prepare earth-based and cement-based mortars with a ratio of 6% of binder. Microstructure analyses through SEM/EDS, water absorption, moisture buffering, mechanical strength, and porosity are discussed. The biostabiliser decreases water absorption in tidal-splash and saturated environments for earth and cement mortars due to calcium carbonate precipitation. The biostabiliser can prevent water migration more effectively for the cement-based (60% reduction) than for the earth-based mortars (up to 10% reduction) in the first 1 h of contact with water. In an adsorption/desorption environment, the conditions favour desorption in cem+bio, and it seems that the biostabiliser precipitation facilitates the release of the chemicals into the mobile phase. The precipitation in the earth+bio mortar porous media conditions favours the adsorption of water molecules, making the molecule adhere to the stationary phase and be separated from the other sample chemicals. The SEM/EDS performed for the mortars confirms the calcium carbonate precipitation and shows that there is a decrease in the quantity of Si and K if the biostabiliser is used in cement and earth-mortars. This decrease, associated with the ability of S. oneidensis to leach silica, is more impressive for earth+bio, which might be associated with a dissolution of silicate structures due to the presence of more water. For the tested earth-based mortars, there was an increase of 10% for compressive and flexural strength if the biostabiliser was added. For the cement-based mortars, the strength increase was almost double that of the plain one due to the clay surface negative charge in the earth-based compositions.

Development and evaluation of Moringa extract incorporated Chitosan/Guar gum/Poly (vinyl alcohol) active films for food packaging applications

The present study contributes the synthesis of active films with the incorporation of moringa extract (ME) into chitosan (CS)/guar gum (GG)/poly(vinyl alcohol) (PVA) matrix (CGPM) by simple solvent casting technique. The effect of ME on the mechanical, thermal, structural and morphological properties of CGPM active films were investigated. ME has shown a marked influence on the optical, thermal properties and swelling behaviour of CGPM active films. The improvement in the tensile strength of CGPM-1 active film (53.7 MPa) was observed compared to control CS/GG/PVA (CGP) film. DSC study revealed that glass transition temperature (Tg) and melting temperature (Tm) decreased with the addition of ME in the CGP matrix, which confirmed the miscibility among the components of active films. There was an improvement in the thermal stability of the CGPM active films. The FTIR study confirmed the molecular interaction between ME and CS/GG/PVA matrix. The XRD analysis showed a decrease in crystallinity with an increase in the ratio of CS for CGPM active films. The CGPM active films were an excellent barrier to UV- light and have exhibited a decrease in moisture adsorption and water solubility compared to CGP control film. The inclusion of ME in the CGP matrix leads to the formation of a dense compact surface, which in turn enhanced hydrophobicity of active films. The CGPM active films showed minimum WVP, OP values and overall migration values were within the limits of 10 mg/dm2. It was also observed that CGPM active films effectively inhibited the growth of E. coli and S. aureus bacteria. These findings suggest CGPM active films are biodegradable, biocompatible, non-toxic and hence can find application as food packaging materials.

Recent advances on nanocellulose biomaterials for environmental health photoremediation: An overview

As one of the potential bionanomaterials, nanocellulose has appeared as a favorable candidate for photoremediation of the environment because of its abundance in nature, inexpensive, eco-friendly, decomposable, high surface area, and outstanding mechanical properties. The current review carefully summarized the diverse type of nanocellulose, their preparation approaches, and several previous works on the use of nanocellulose for photoremediation. These include the role of nanocellulose for the increased surface active site of the hybrid photocatalysts by providing a large surface area for enhanced adsorption of photons and pollutant molecules, as a dispersing agent to increase distribution of metal/non-metal dopants photocatalysts, as well as for controlled size and morphology of the dopants photocatalysts. Furthermore, the recommendations for upcoming research provided in this review are anticipated to ignite an idea for the development of other nanocellulose-based photocatalysts. Other than delivering beneficial information on the present growth of the nanocellulose biomaterials photocatalysts, this review is expected will attract more interest to the utilization of nanocellulose photocatalyst and distribute additional knowledge in this exciting area of environmental photoremediation. This could be attained by considering that a review on nanocellulose biomaterials for environmental health photoremediation has not been described elsewhere, notwithstanding intensive research works have been dedicated to this topic.

Recent development in fabrication and evaluation of phenolic-dietary fiber composites for potential treatment of colonic diseases

Phenolics have been shown by in vitro and animal studies to have multiple pharmacological effects against various colonic diseases. However, their efficacy against colonic diseases, such as inflammatory bowel diseases, Crohn's disease, and colorectal cancer, is significantly compromised due to their chemical instability and susceptibility to modification along the gastrointestinal tract (GIT) before reaching the colonic site. Dietary fibers are promising candidates that can form phenolic-dietary fiber composites (PDC) to carry phenolics to the colon, as they are natural polysaccharides that are non-digestible in the upper intestinal tract but can be partially or fully degradable by gut microbiota in the colon, triggering the release at this targeted site. In addition, soluble and fermentable dietary fibers confer additional health benefits as prebiotics when used in the PDC fabrication, and the possibility of synergistic relationship between phenolics and fibers in alleviating the disease conditions. The functionalities of PDC need to be characterized in terms of their particle characteristics, molecular interactions, release profiles in simulated digestion and colonic fermentation to fully understand the metabolic fate and health benefits. This review examines recent advancements regarding the approaches for fabrication, characterization, and evaluation of PDC in in vitro conditions.

Synthesis, characterization, and humidity-responsiveness of guar gum xanthate and its nanocomposite with copper sulfide covellite

A novel conjugation of guar gum with xanthate groups via facile aqueous xanthation reaction has been reported. Density of grafted xanthate on guar gum product (GG-X) is as high as 4.4%, thus GG-X is conceivably characterized and confirmed by various spectrometric, electrochemical, thermogravimetric, and microscopic methods. Complexation of GG-X with numerous borderline and soft metal ions (e.g. Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Pb²⁺, Pt²⁺ and Cd²⁺) yields hydrophilic gel-like materials and shows good agreement with hard and soft acid and base (HSAB) theory. This indicates tremendous potential of GG-X in metal ion extraction, removal and hydrogel cross-linking. GG-X is also employed to formulate an aqueous colloidal dispersion of copper sulfide covellite (GG-X/CuS) nanocomposites. GG-X therefore behaves as a surfactant, allowing formation of electronically conductive nanocomposites. XRD indicates apparent beneficial effects of GG-X in the synthesis of CuS with a crystallite size of 15.6 nm. This novel nanocomposite is a promising material for humidity sensing, showing reversible linear responses to relative humidity changes within 10 to 80% range. The interaction between GG-X and water might cause changes in electrical permittivity of GG-X/CuS nanocomposite and/or electrical hopping conductivity between CuS nanoparticles.

Performance of novel GO-Gly/HNTs and GO-GG/HNTs nanocomposites for removal of Pb(II) from water: optimization based on the RSM-CCD model

For the first time, in this study, two novel glycogen-graphene oxide/halloysite nanotubes (GO-Gly/HNTs) and guar gum-graphene oxide/halloysite nanotubes (GO-GG/HNTs) nanocomposites were synthesized as the adsorbents for removal of Pb(II) from water, and the ionic liquid was used in the synthesis as a green solvent. According to the SEM, TEM, EDS, BET, zeta potential, FTIR, and XRD results, GO-Gly/HNTs and GO-GG/HNTs were synthesized successfully. Response surface methodology (RSM) was applied to optimize the experimental conditions. Nanocomposites followed the Langmuir equilibrium model and were best fitted to the pseudo-second-order model. According to the thermodynamic model, the adsorption process was endothermic. Due to several features, these two novel nanocomposites can be considered the proper candidate for Pb(II) removal from water and wastewater. First, these nanocomposites have good adsorption capacity for Pb(II) removal, which is 219 mg/g for GO-Gly/HNTs and 315 mg/g for GO-GG/HNTs. Moreover, nanocomposites can be recycled with proper adsorption capacity after four repeated cycles. These materials can be used to remove Pb(II) from water in the presence of other contaminants because nanocomposites have selective tendency toward Pb(II) in the presence of other pollutants such as Cd²⁺, Cu²⁺, Cr²⁺, and Co²⁺. In addition, the presence of Ca²⁺, Mg²⁺, Na⁺, and K⁺ improve Pb(II) removal. Finally, possible mechanisms for each nanocomposite were represented.

A comprehensive review on the removal of noxious pollutants using carrageenan based advanced adsorbents

Rapid industrial development is associated with high discharge of toxic pollutants into the environment. The industries discharge their wastewater containing organic pollutants directly into the water system without treating them that has posed many serious threats to environmental protection. The use of bioadsorbents for the removal of such toxic pollutants from the waste water due to its simple synthesis, easy operation, effectiveness, and economic viability have emerged a new dimension in the wastewater treatment approaches. Various adsorbents have been prepared to examine their adsorption capacity against different adsorbates, but, to attain sustainability, biocompatibility, and biodegradation, bio-adsorbents have been found to won the battle. Seaweed derived polysaccharide; Carrageenan (CR) has been proven to be an excellent adsorbent for the wastewater treatment. It has been successfully modified with various components to form CR based-magnetic composites, hydrogels, nanoparticle modified CR composites and many others to enrich and diversify its properties. In this review, we have explained the adsorption behaviour of various carrageenan based adsorbents for the removal of different dyes. The influence of various parameters such as the effect of initial concentration, adsorbent dosage, contact time, pH, temperature, and ion concentration on dye adsorption is well explained. This paper also summarizes the structure, morphology, swelling ability, and thermal stability of carrageenan. The data also expounds on the adsorption capacity, kinetic model, isotherm model, and nature of the adsorption process. Different types of solvents are used for the regeneration and reusability of carrageenan adsorbents and their regeneration studies and desorption efficiency is well-explained. The adsorption mechanism of dyes onto carrageenan based adsorbents has been well described in this review. This review provides a deep insight about the use of carrageenan based adsorbents for the wastewater treatment.

Deciphering Molecular Mechanisms Involved in Salinity Tolerance in Guar (Cyamopsis tetragonoloba (L.) Taub.) Using Transcriptome Analyses

Guar is a commercially important legume crop known for guar gum. Guar is tolerant to various abiotic stresses, but the mechanisms involved in its salinity tolerance are not well established. This study aimed to understand molecular mechanisms of salinity tolerance in guar. RNA sequencing (RNA-Seq) was employed to study the leaf and root transcriptomes of salt-tolerant (Matador) and salt-sensitive (PI 340261) guar genotypes under control and salinity. Our analyses identified a total of 296,114 unigenes assembled from 527 million clean reads. Transcriptome analysis revealed that the gene expression differences were more pronounced between salinity treatments than between genotypes. Differentially expressed genes associated with stress-signaling pathways, transporters, chromatin remodeling, microRNA biogenesis, and translational machinery play critical roles in guar salinity tolerance. Genes associated with several transporter families that were differentially expressed during salinity included ABC, MFS, GPH, and P-ATPase. Furthermore, genes encoding transcription factors/regulators belonging to several families, including SNF2, C₂H₂, bHLH, C3H, and MYB were differentially expressed in response to salinity. This study revealed the importance of various biological pathways during salinity stress and identified several candidate genes that may be used to develop salt-tolerant guar genotypes that might be suitable for cultivation in marginal soils with moderate to high salinity or using degraded water.

Polysaccharides to combat viruses (Covid-19) and microbes: New updates

COVID-19, which is speedily distributed across the world and presents a significant challenge to public health, is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Following MERS coronavirus (MERS-CoV) and SARS, this is the third severe coronavirus outbreak in less than 20 years. To date, there are no exact agents and vaccines available for the treatment of COVID-19 that are clinically successful. Antimicrobial medications are effective in controlling infectious diseases. However, the extensive use of antibiotics makes microbes more resistant to drugs and demands novel bioactive agents' development. Polysaccharides are currently commonly used in the biomedical and pharmaceutical industries for their remarkable applications. Polysaccharides appear to have a wide range of anti-virus (anti-coronavirus) and antimicrobial applications. Polysaccharides are able to induce bacterial cell membrane disruption as they demonstrate potency in binding onto the surfaces of microbial cells. Here, the antiviral mechanisms of such polysaccharides and their success in the application of antiviral infections are reviewed. Additionally, this report provides a summary of current advancements of well-recognized polysaccharides as antimicrobial and anti-biofilm agents.

Synthesis, characterization and biocompatibility of guar gum-benzoic acid

A novel chemical functionalization of guar gum (GG) by benzoic acid (BA) via nucleophilic substitution reaction in aqueous solution has been reported. BA moieties are chosen due to coordination chemistry of carboxylic acid moieties, hydrophobicity and intermolecular interaction of aromatic rings. The presence of conjugated BA on guar gum-benzoic acid (GG-BA) with grafting density of 5.5% is confirmed by ¹H NMR. Amorphous GG-BA with irregular morphology has been studied by UV-Vis, FTIR, XRD, SEM, TEM, TGA, computational chemistry and contact angle measurement. GG-BA in a concentration range from 0 to 4000 μg mL^-1 has good biocompatibility to mouse embryonic fibroblasts (MEF), human mammary epithelial cells (MCF-10A) after 48 and 72 h of treatment using WST-1 assay. GG-BA shows great potential for the development of biomaterials such as bioadhesives, hydrogels, and coacervates.

Changes in Structural and Rheological Properties of Guar Gum Particles in Fluidized-Bed Agglomeration: Effect of Sucrose Binder Concentration

Fluidized-bed agglomeration (FBA) is known to modify the structure and rheology of food powders. In this study, guar gum (GG) powders with various concentrations of sucrose binder (0%, 10%, 20%, or 30%) were subjected to fluidized-bed agglomeration. Subsequently, changes in the characteristics of the GG powders were evaluated by using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), particle size distribution (PSD) analysis, and rheological and dispersibility measurements. SEM images and FTIR spectra revealed surface morphology changes and structural modification, respectively, in the original GG powder after FBA, although the changes observed in FTIR spectra were only slightly dependent on sucrose concentration at low concentrations (0–20%). XRD patterns confirmed that the crystallinity of the GG powder was affected by FBA, but not greatly so by binder concentration. The PSD results showed that the GG particle size was increased by FBA and there was a clear relationship between sucrose concentration (10–30%) and mean particle size. The rheological behavior and dispersibility of GG (properties that are known to be affected by the structure of a powder) were also influenced by sucrose concentration. To sum up, FBA and the concentration of sucrose binder used can serve as factors for modifying GG powder.

Understanding the microstructure, mineralogical and adsorption characteristics of guar gum blended soil as a liner material

Guar gum blended soil (GGBS) offers potentially advantageous engineering characteristics of hydraulic conductivity and strength for a soil to be used as a liner material. Characterization techniques such as X-ray diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy and scanning electron microscope were used to examine the mineral composition, functional groups and morphological changes in the unblended soil (UBS) and GGBS. These characterization approaches are used to understand adsorption-associated mechanisms of Pb(II) removal. Batch adsorption tests were performed to evaluate the adsorption capacity of UBS and the GGBS with various proportions (0.5%, 1.0%, 1.5% and 2.0%) of guar gum (GG) towards the removal of Pb(II) ions. Batch adsorption experiments were conducted by varying the pH, dosage of adsorbent, concentration of metal ions and contact time. The experimental results showed that the optimum removal of Pb(II) ions was high at a pH of 3.0 for all blends, and adsorption tests beyond 3.0 pH demonstrated a decline in adsorption performance. The maximum Pb(II) removal efficiency of 95% was obtained using the 2.0% GGBS. The isotherm model assessment for adsorption experimental data of Pb(II) showed the best fit for the Langmuir model on using GG. The present research demonstrated that the guar gum-treated blends exhibited potential Pb(II) ion adsorption properties and therefore can be used as sustainable liner material in sanitary landfills.

Progresses in chitin, chitosan, starch, cellulose, pectin, alginate, gelatin and gum based (nano)catalysts for the Heck coupling reactions: A review

Heck cross-coupling reaction (HCR) is one of the few transition metal catalyzed CC bond-forming reactions, which has been considered as the most effective, direct, and atom economical synthetic method using various catalytic systems. Heck reaction is widely employed in numerous syntheses including preparation of pharmaceutical and biologically active compounds, agrochemicals, natural products, fine chemicals, etc. Commonly, Pd-based catalysts have been used in HCR. In recent decades, the application of biopolymers as natural and effective supports has received attention due to their being cost effective, abundance, and non-toxicity. In fact, recent studies demonstrated that biopolymer-based catalysts had high sorption capacities, chelating activities, versatility, and stability, which make them potentially applicable as green materials (supports) in HCR. These catalytic systems present high stability and recyclability after several cycles of reaction. This review aims at providing an overview of the current progresses made towards the application of various polysaccharide and gelatin-supported metal catalysts in HCR in recent years. Natural polymers such as starch, gum, pectin, chitin, chitosan, cellulose, alginate and gelatin have been used as natural supports for metal-based catalysts in HCR. Diverse aspects of the reactions, different methods of preparation and application of polysaccharide and gelatin-based catalysts and their reusability have been reviewed.

Effects of guar gum supplementation on the lipid profile: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

Guar gum can be used as an adjuvant in the treatment of dyslipidemia. However, based on data from different studies, the effectiveness of this product is not uniform. Therefore, we conducted a dose-response meta-analysis between guar gum supplementation and lipid profile.

METHODS AND RESULTS

Five databases (Scopus, Web of Science, PubMed/Medline, Embase, and Google Scholar) were searched to identify relevant articles published up to July 2020. The weighted mean difference (WMD) was derived based on the random-effects model. Overall findings were generated from 25 eligible trials. Patients' conditions included hyperlipidemia, diabetes, metabolic syndrome, hypertension, overweight, carotid endarterectomy, and menopausal women. Prescribed gum dose varied between 100 mg/d and 30 g/d for 1-24 months. Compared with control groups, guar gum supplementation decreased total cholesterol (TC) by -20.41 mg/dL (95% CI: -26.76 to -14.07; P < 0.001) and low-density lipoprotein-cholesterol (LDL-C) by -17.37 mg/dL (95% CI: -23.60 to -11.13; P < 0.001), but did not change triglycerides (TG) (WMD: -6.53 mg/dL, 95% CI: -16.03 to 2.97; P = 0.178) and high-density lipoprotein-cholesterol (HDL-C) (WMD: -0.62 mg/dL, 95% CI: -1.68 to 0.44, P = 0.252).

CONCLUSIONS

Guar gum supplementation significantly reduced serum LDL-C and TC levels in patients with cardiometabolic problems, but had neutral effects on TG and HDL-C levels.

Guar (Cyamopsis tetragonoloba L.) plant gum: From biological applications to advanced nanomedicine

Natural polymers are an efficient class of eco-friendly and biodegradable polymers, because they are readily available, come from natural sources, inexpensive and can be chemically modified with the correct reagents. Guar gum (GG) is a natural polymer with great potential to be used in pharmaceutical formulations due to its unique composition and lack of toxicity. GG can be designed to suit the needs of the biological and medical engineering sectors. In the development of innovative drug delivery systems, GG is commonly utilized as a rate-controlling excipient. In this review, different properties of GG including chemical composition, extraction methods and its usefulness in diabetes, cholesterol lowering, weight control, tablet formulations as well as its food application were discussed. The other purpose of this study is to evaluate potential use of GG and its derivatives for advanced nanomedicine such as drug delivery, tissue engineering and nanosensing. It should be noted that some applicable patents in medical area have also been included in the rest of this survey to extend knowledge about guar gum and its polymeric nature.

Toxicological studies and some functional properties of carboxymethylated cellulose nanofibrils as potential food ingredient

Carboxymethylated cellulose nanofibrils (CNF) with different carboxyl contents (0, 0.36, 0.72 and 1.24 mmol/g) were prepared and characterized via morphology, diameter distribution, zeta potential, structural features, rheological properties, suspension stability, and thermal properties. The results of toxicological studies of ingested CNF via in vitro and in vivo models were present. In vitro studies used an epithelial-like cell line (Caco-2) to assess the effects of a 24 h incubation with CNF, in which no significant cytotoxicity was observed. In vivo studies were evaluated in mice gavage once per day for 8 weeks with 1% or 3.5% w/w suspension of CNF in water. Blood and serum were collected for analysis. No significant differences in hematology, and serum markers were observed between controls and mice given CNF suspensions. Weight, food intake and feces were recorded for growing development and nutrient retention in feces was measured for investigation of functional properties of CNFs. Mice given CNF suspensions gained a significant increment in fecal fat but a reduction in food intake and weight compared to controls. These findings suggested that CNFs are non-toxic and have potentials in behaving as food additives or supplements to reduce caloric intake.

Recent Advances in Biotechnological Itaconic Acid Production, and Application for a Sustainable Approach

Intense research has been conducted to produce environmentally friendly biopolymers obtained from renewable feedstock to substitute fossil-based materials. This is an essential aspect for implementing the circular bioeconomy strategy, expressly declared by the European Commission in 2018 in terms of "repair, reuse, and recycling". Competent carbon-neutral alternatives are renewable biomass waste for chemical element production, with proficient recyclability properties. Itaconic acid (IA) is a valuable platform chemical integrated into the first 12 building block compounds the achievement of which is feasible from renewable biomass or bio-wastes (agricultural, food by-products, or municipal organic waste) in conformity with the US Department of Energy. IA is primarily obtained through fermentation with Aspergillus terreus, but nowadays several microorganisms are genetically engineered to produce this organic acid in high quantities and on different substrates. Given its trifunctional structure, IA allows the synthesis of various novel biopolymers, such as drug carriers, intelligent food packaging, antimicrobial biopolymers, hydrogels in water treatment and analysis, and superabsorbent polymers binding agents. In addition, IA shows antimicrobial, anti-inflammatory, and antitumor activity. Moreover, this biopolymer retains qualities like environmental effectiveness, biocompatibility, and sustainability. This manuscript aims to address the production of IA from renewable sources to create a sustainable circular economy in the future. Moreover, being an essential monomer in polymer synthesis it possesses a continuous provocation in the biopolymer chemistry domain and technologies, as defined in the present review.

Emerging novel polymeric adsorbents for removing dyes from wastewater: A comprehensive review and comparison with other adsorbents

Dye molecules are one of the most hazardous compounds for human and animal health and the excess intake of these materials can create toxic impacts. Several studies show the practicality of the adsorption process for dye uptake from wastewaters. In recent years, various adsorbents were used to be efficient in this process. Among all, polymeric adsorbents demonstrate great applicability in different environmental conditions and attract many researchers to work on them, although there is not enough reliable and precise information regarding these adsorbents. This study aims to investigate some influential parameters such as their type, physical properties, experimental conditions, their capacity, and further modeling along with a comparison with non-polymeric adsorbents. The influence of the main factors of adsorption capacity was studied and the dominant mechanism is explained extensively.

Characterization of hydrophobic interaction of galactomannan in aqueous solutions using fluorescence-based technique

Fluorescence probing was used to study hydrophobic interactions of galactomannan (GM) obtained from fenugreek gum (FG), guar gum (GG), and locust bean gum (LBG) at different M/G ratios. The I₁/I₃ ratio of pyrene changed from 1.73 to 1.29, 1.22, and 1.29 for FG, GG and LBG, respectively, as the concentration of GM increased from 0.01 to 8.0 g/L at 30 °C. The critical aggregation concentration of FG, GG, and LBG increased from 1.04 to 3.84 g/L, 1.15 to 3.73 g/L, and 0.94 to 3.63 g/L, respectively, as temperature increased from 10 to 70 °C. Addition of Na₂SO₄ and NaSCN increased the I₁/I₃ ratio in dilute solution, but reduced it in semi-dilute solution, whereas adding urea reduced I₁/I₃ in dilute solution but increased it in semi-dilute solution. These results indicated that the CAC of GM, polarity and number of hydrophobic microdomains were highly dependent on the M/G ratio and galactose distribution.