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

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.

Rheological and water binding properties of xanthan, guar and ultra-finely milled oatmeal in white birch sap: Influence of sap minor constituents

White Birch Sap (WBS) contains appreciable amounts of mineral ions and phenolic compounds and can be used as alternate solvent for food applications. In this study, the effect of the mineral and phenolic composition of WBS was evaluated on the physical properties of xanthan gum, guar gum, ultra-finely milled oatmeal and their combinations in solution. Solutions were formulated with WBS and with solvents mimicking WBS without phenolic compounds and WBS without phenolics nor mineral ions. The influence of solvent composition was evaluated on flow properties and water mobility of the solutions. From WBS without mineral ions nor phenolics, the addition of mineral ions led to increased pseudo-plasticity and decreased flow consistency, and decreased water mobility. Addition of phenolic compounds through WBS led to opposite effects possibly due to phenolic-driven aggregation of the hydrocolloids which also seemed to inhibit guar/xanthan interactions.

Guar gum-derived galactomannan induces inflammatory responses and increased energy expenditure in the intestine

Guar gum-derived galactomannan (GGGM) has been widely used in the food industry for a long time and its adverse impacts have been scarcely reported. Galactomannan is considered to have a structure similar to the surface components of certain pathogens, and the present study was thus conducted to investigate if oral administration of GGGM could cause physiological effects that were hypothesized to be related to intestinal inflammatory responses. The results showed that oral administration of GGGM resulted in compromises on growth performance, an increase of the relative weight of spleen and epididymal fat, and an elevation of the α1-acid glycoprotein content in both serum and livers of mice. With regard to energy metabolism-related indices, the activities of intestinal lactic dehydrogenase and succinic dehydrogenase were all increased by the GGGM treatment in both in vivo and in vitro experiments, the latter of which also showed an elevation in the consumption of reducing sugar by intestinal epithelial cells along with a reduced viability of these cells in response to the GGGM treatment. Notably, the GGGM treatment triggered intestinal inflammatory responses that were evidenced by the increased expression of intestinal inflammatory cytokines such as TNF-α and IL-6 both in vivo and in vitro, which were at least partially responsible for the increased energy expenditure in the intestine and the retardation of growth. The results of this study could expand our knowledge of GGGM administration and provide integrated insights into the consumption of GGGM-containing foods.

Guar gum based nanocomposites: Role in water purification through efficient removal of dyes and metal ions

Researchers nowadays are relentlessly on a race exploring sustainable materials and techniques for the sequestration of toxic dyes and metal ions from water bodies. Biopolymers such as guar gum, owing to its high abundance, low cost and non-toxicity, are potential candidates in this field. Plenty of hydroxyl groups in the polymer backbone enable guar gum to be functionalised or grafted in a versatile manner proving itself as an excellent starting substance for fabricating upgraded materials meant for diverse applications. This review offers a comprehensive coverage of the role of guar gum-based nanocomposites in removal of dyes and heavy metal ions from waste water through adsorption and photo-catalytic degradation. Isotherm and kinetics models, fabrication routes, characterisation techniques, swelling properties and reusability as well as adsorption and degradation mechanisms are outlined. A detailed analysis with convincing results suggests a good future perspective of implementation of these materials in real-time wastewater treatment technology.

Synthesis of pH-sensitive crosslinked guar gum-g-poly(acrylic acid-co-acrylonitrile) for the delivery of thymoquinone against inflammation

The present work aims to synthesize the pH-sensitive crosslinked guar gum-g-poly(acrylic acid-co-acrylonitrile) [guar-g-(AA-co-ACN)] via microwave-assisted technique for the sustained release of thymoquinone. The synthesized material [guar-g-(AA-co-ACN)] was optimized by varying synthetic parameters viz. monomer concentration, reaction time, and microwave power to obtain the maximum yield of the crosslinked guar gum grafted product as well as maximum encapsulation of thymoquinone. The synthesized material [guar-g-poly(AA-co-ACN)] was characterized by FT-IR, SEM, XRD, NMR, zeta potential, and thermal techniques. This synthesized material was used to encapsulate thymoquinone (TQ) for effective nanotherapeutic delivery. In-vitro thymoquinone release behavior of guar-g-poly(AA-co-ACN) based nanoparticles (NpTGG) was investigated. The maximum thymoquinone release (78%) was achieved at pH 7.4 and time (6 h). The NpTGG also exhibited better antioxidant activity and hemocompatibility as compared to thymoquinone. Cytotoxicity of uar-g-(AA-co-ACN) and NpTGG was also evaluated against the human kidney VERO cell line and found to be nontoxic. Current research provides a cost-effective and green approach for the synthesis of guar-g-(AA-co-ACN) and NpTGG for sustained release of thymoquinone.

Biopolymer-derived (nano)catalysts for hydrogen evolution via hydrolysis of hydrides and electrochemical and photocatalytic techniques: A review

Over the course of a few decades, the concern of environmental damages of fossil fuels, an increase in CO₂ emission and a decrease of hydrogen have been growing more and more. Accordingly, hydrogen production is a crucial issue nowadays. Different polymers are applied to attain the purpose. Among all polymers, biodegradables polymers are the best choices to develop the main aim. Polysaccharides and proteins are biodegradable polymers with unique places and advantages with regards to their ecofriendly properties. There are different techniques to apply and achieve the foremost purpose. It is worthwhile to mention that green and facile methods are always attracting attention in different aspects and fields. The three non-polluting and economical techniques, that is, electrochemical hydrogen evolution reaction (HER), photocatalytic technique, and hydrolysis of hydrides, are reviewed in this paper. This review helps researchers, who are environment supporters, to evaluate and choose the most ecological biopolymers and processes in their work.

Adsorption-photocatalysis performance of polyaniline/dicarboxyl acid cellulose@graphene oxide for dye removal

A novel 3-D biopolymer-based adsorption-photocatalytic composite, polyaniline/dicarboxyl acid cellulose@graphene oxide was synthesized and was employed to remove the reactive brilliant red K-2G from aqueous solution. The addition of dicarboxyl acid cellulose could improve the morphology, structure, stability and dispersity of the nanocomposite, thus providing excellent adsorption and photocatalysis performance to the product. Batch of experiments were conducted in two scenarios: adsorption followed by photocatalysis process and simultaneous adsorption-photocatalysis process. For the first scenario, adsorption equilibrium can be reached within 25 min, the expected adsorption capacity was 447.0 mg·g^-1; the subsequent photocatalysis process was carried out under light irradiation and the removal capacity could further improve to 729.0 mg·g^-1 under equilibrium state (about 180 min). For the simultaneous adsorption-photocatalytic process, the removal capacity was about 558.1 mg·g^-1 at about 25 min and the total removal capacity could reach to 733.3 mg·g^-1 under equilibrium state. PANI-DCC@GO exhibited excellent reusability and had potential in the treatment of dyes polluted wastewater.

An injectable double-crosslinking iodinated composite hydrogel as a potential radioprotective spacer with durable imaging function

Prostate cancer is one of the leading causes of cancer incidence among males worldwide. Radiotherapy can achieve similar oncological outcomes to those of radical prostatectomy. One concern is, however, radiation damage to the rectum because of the extreme proximity between the two organs. Inserting a biomaterial to separate the prostate and rectum is a promising strategy, and an injectable hydrogel is regarded to be the preferred spacer after screening of various materials. Nevertheless, there exist shortcomings for the currently available injectable hydrogel that cannot fully meet the unique requirements in clinical practice. In this work, a novel injectable hydrogel spacer based on carboxymethyl chitosan (CMC), aldehyde guar gum (AG), and aldehyde iohexol (DHQ) with an imaging function is fabricated. Contrast agent DHQ is chemically attached to CMC-AG network to form a double-crosslinking network to obtain a controlled degradation rate and high strength as well as durable CT imaging function. The hydrogel is injected subcutaneously into rats, where rapid gelation occurs and it serves as a hydrogel spacer. During the month-long in vivo studies, the spacer exhibits remarkable radiation dose attenuation and sustainable imaging function, as well as excellent toxicity profiles. This novel hydrogel shows excellent potential in the protection of critical organs during prostate cancer radiotherapy.

Recent advances in guar gum based drug delivery systems and their administrative routes

Guar gum-based drug carrier systems have gained attention for the delivery of various therapeutic agents via different administration routes for attaining controlled and sustained release. Guar gum offers a safe and effective system for drug delivery due to its natural occurrence, easy availability, biocompatibility, and biodegradability, besides simple and mild preparation techniques. Furthermore, the possibility of using various routes such as oral, buccal, transdermal, intravenous, and gene delivery further diversify guar gum applications in the biomedical field. This review delineates the recent investigation on guar gum-based drug carrier systems like hydrogels, nanoparticles, nanocomposites, and scaffolds along with their related delivery routes. Also, the inclusion of data of the loading and subsequent release of the drugs enables to explore the noble and improved drug targeting therapies.

Plant Prebiotics and Their Role in the Amelioration of Diseases

Prebiotics are either natural or synthetic non-digestible (non-)carbohydrate substances that boost the proliferation of gut microbes. Undigested fructooligosaccharides in the large intestine are utilised by the beneficial microorganisms for the synthesis of short-chain fatty acids for their own growth. Although various food products are now recognized as having prebiotic properties, several others, such as almonds, artichoke, barley, chia seeds, chicory, dandelion greens, flaxseeds, garlic, and oats, are being explored and used as functional foods. Considering the benefits of these prebiotics in mineral absorption, metabolite production, gut microbiota modulation, and in various diseases such as diabetes, allergy, metabolic disorders, and necrotising enterocolitis, increasing attention has been focused on their applications in both food and pharmaceutical industries, although some of these food products are actually used as food supplements. This review aims to highlight the potential and need of these prebiotics in the diet and also discusses data related to the distinct types, sources, modes of action, and health benefits.

Poly(β-cyclodextrin)-Activated Carbon Gel Composites for Removal of Pesticides from Water

Pesticides are widely used in agriculture to increase and protect crop production. A substantial percentage of the active substances applied is retained in the soil or flows into water courses, constituting a very relevant environmental problem. There are several methods for the removal of pesticides from soils and water; however, their efficiency is still a challenge. An alternative to current methods relies on the use of effective adsorbents in removing pesticides which are, simultaneously, capable of releasing pesticides into the soil when needed. This reduces costs related to their application and waste treatments and, thus, overall environmental costs. In this paper, we describe the synthesis and preparation of activated carbon-containing poly(β-cyclodextrin) composites. The composites were characterized by different techniques and their ability to absorb pesticides was assessed by using two active substances: cymoxanil and imidacloprid. Composites with 5 and 10 wt% of activated carbon showed very good stability, high removal efficiencies (>75%) and pesticide sorption capacity up to ca. 50 mg g-1. The effect of additives (NaCl and urea) was also evaluated. The composites were able to release around 30% of the initial sorbed amount of pesticide without losing the capacity to keep the maximum removal efficiency in sorption/desorption cycles.

Hydroxy citric acid cross-linked chitosan/guar gum/poly(vinyl alcohol) active films for food packaging applications

The present work aims to prepare Chitosan (CS)/Guar gum (GG)/Poly(vinyl alcohol) (PVA) cross-linked with Hydroxy citric acid (HCA) (CGPH active film) by solvent casting technique. The influence of HCA on different CS/PVA ratio (1:3, 1:1, 3:1) in presence of the fixed amount of GG (0.2%) was investigated. The analysis of the results showed that the addition of HCA to the different ratio of CS/PVA increased the degradation temperature and improved the mechanical properties of CGPH active films. FTIR spectra and XRD analysis revealed strong interactions among the components of CGPH active films. The analysis of SEM images and water contact angle suggested a compact, dense film surface with hydrophobic nature. Further, all the active films have shown a decrease in water vapour permeability (WVP) and acted as a barrier to UV-light. CGPH active films effectively inhibited the growth of S. aureus and E. coli bacteria. With all these features the CGPH active films can find application in food packaging.

Processing Guar Gum into polyester fabric based promising mixed matrix membrane for water treatment

A reactive and mechano-chemically stable support was prepared from Ag-nanoparticles decorated polyester fabric which was subsequently coated by a casting solution containing polyvinylidene fluoride matrix, guar gum (GG) exo-polysaccharide hydrophilic agent, and UiO-66 filler. FE-SEM, XRD, FT-IR, water contact angle technique, and mechanical stability tests were applied to characterize the prepared membranes. The water contact angle measurements indicated the hydrophilicity of the prepared membrane which can be attributed to the nature of bio-GG and UiO-66. The prepared membrane was employed for purifying contaminated waters containing N-cetyl-N,N,N-trimethylammonium bromide (CTAB) and congo-red (CR) dye through a cross-module set-up. The central composite design was also exploited to study the effect of operational parameters such as CTAB and CR concentration, pH solution, and pressure on the removal efficiency. Particularly, the bio-based GG/UiO-66 dispersion showed excellent self-healing properties, which enabled an effective pollutant separation ability and facilitated the recyclability/sustainability of the as-prepared membrane.

Guar gum based hydrogel as controlled micronutrient delivery system: Mechanism and kinetics of boron release for agricultural applications

A boron loaded super-absorbent hydrogel (BLSAH) was developed through in situ incorporation of boron (B) in a guar gum-based hydrogel and characterized with FTIR, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), and swelling studies, showing maximum absorption up to 356 g/g. The release pattern of B from the BLSAH and its kinetics was studied in water as well as soil. The B release pattern of the BLSAH was also compared with the commercial B fertilizer, boronated single super phosphate (bSSP). The BLSAH, following the Fickian mechanism, released 38% B, as compared with 51% of the bSSP, during the incubation period of 30 days in soil. The half-life period for the BLSAH (96.25 days) in soil was almost triple that of the bSSP's half-life (33.32 days), which is indicative of the slow and controlled release of B from the BLSAH. Thus, owing to its sustained nutrient release ability, the synthesized BLSAH exhibited wide potential for applications in agriculture sector.

Starch, cellulose, pectin, gum, alginate, chitin and chitosan derived (nano)materials for sustainable water treatment: A review

Natural biopolymers, polymeric organic molecules produced by living organisms and/or renewable resources, are considered greener, sustainable, and eco-friendly materials. Natural polysaccharides comprising cellulose, chitin/chitosan, starch, gum, alginate, and pectin are sustainable materials owing to their outstanding structural features, abundant availability, and nontoxicity, ease of modification, biocompatibility, and promissing potentials. Plentiful polysaccharides have been utilized for making assorted (nano)catalysts in recent years; fabrication of polysaccharides-supported metal/metal oxide (nano)materials is one of the effective strategies in nanotechnology. Water is one of the world's foremost environmental stress concerns. Nanomaterial-adorned polysaccharides-based entities have functioned as novel and more efficient (nano)catalysts or sorbents in eliminating an array of aqueous pollutants and contaminants, including ionic metals and organic/inorganic pollutants from wastewater. This review encompasses recent advancements, trends and challenges for natural biopolymers assembled from renewable resources for exploitation in the production of starch, cellulose, pectin, gum, alginate, chitin and chitosan-derived (nano)materials.

Optimizing the properties of Zodo gum and examining its potential for amino acid binding by periodate oxidation

In this study, the Zodo gum exudated by Amygdalus scoparia spach underwent the periodate oxidation process for chemical modification and the formation of dialdehyde groups. Modification of the Zodo gum properties was done using the periodate oxidation method, response surface methodology (RSM) and central composite design (CCD), with 4 factors of sodium periodate volume (6.4-19.2 mL), temperature (35-55 °C), pH (3-5) and time (2-4 h). Dialdehyde Zodo gum (DZG) was produced by controlling test variables and measuring some responses including dialdehyde content and efficacy, in addition to evaluating the rheological parameters. Quadratic, linear polynomial equations were then fitted with the insignificant Lack of fit and high R² to address the relationship between the mentioned variables and responses. Optimal test conditions, including pH = 3.9, T = 43 °C and Time = 3.5 h, were also determined for the production of DZG₁₀, DZG₂₀ and DZG₃₀ samples. The results of ¹H-¹³C NMR, FTIR and determination of the aldehyde content indicated the formation of dialdehyde groups in equilibrium with the dominant hemiacetal form. The AFM study of the DZG₃₀ sample also showed over-oxidation and depolymerization, which could be associated with increased hydrophobic properties and the reduced viscosity. Although the DZG₃₀ sample had the highest amount of the dialdehyde factor group with the tendency to combine with the amino group of proteins, DZG₁₀ and DZG₂₀ samples could be recommended for industrial applications due to the nonoccurrence of overoxidation.

Sustainable landfill leachate treatment: Optimize use of guar gum as natural coagulant and floc characterization

Sustainable wastewater treatment necessitates the application of natural and green material in the approach. Thus, selecting a natural coagulant in leachate treatment is a crucial step in landfill operation to prevent secondary environmental pollution due to residual inorganic coagulant in treated effluent. Current study investigated the application of guar gum in landfill leachate treatment. Central composite design in response surface methodology was used to optimize the performance of Chemical Oxygen Demand (COD) removal. Quadratic model developed indicated the optimum COD removal 22.57% at guar gum dosage of 44.39 mg/L, pH 8.56 (natural pH of leachate) and mixing speed 79.27 rpm. Scanning electron microscopy showed that floc was compact and energy-dispersive-x-ray analysis showed that guar gum was capable to adsorb multiple ions from the leachate. Structural characterization using Fourier Transform Infrared analysis demonstrated that hydrogen bonding between guar and pollutant particles was involved in coagulation and flocculation process. Therefore, guar gum coagulant present potential to be an alternative in leachate treatment where pH requirement is not required during treatment. Simultaneously, adsorption by guar gum offers added pollutant removal advantage.

Microbially induced calcite precipitation using Bacillus velezensis with guar gum

Mineral precipitation via microbial activity is a well-known process with applications in various fields. This relevance of microbially induced calcite precipitation (MICP) has pushed researchers to explore various naturally occurring MICP capable bacterial strains. The present study was performed to explore the efficiency of microbially induced calcite precipitation (MICP) via locally isolated bacterial strains and role of guar gum, which is a naturally occurring polymer, on the MICP process. The strains were isolated from local soil and screened for urease activity Further, the urease positive strain was subjected to urea and calcium chloride based medium to investigate the efficacy of isolated strain for microbial induced precipitation. Among screened isolates, the soil bacterium that showed urease positive behaviour and precipitated calcium carbonate was subjected to 16S rRNA gene sequencing. This strain was identified as Bacillus velezensis. Guar gum—a natural polymer, was used as a sole carbon source to enhance the MICP process. It was observed that the isolated strain was able to breakdown the guar gum into simple sugars resulting in two-fold increase in calcium carbonate precipitate. Major bio-chemical activities of isolated strain pertaining to MICP such as ammonium ion concentration, pH profiling, and total reducing sugar with time were explored under four different concentrations of guar gum (0.25%, 0.5%, 0.75% and 1% w/v). Maximum ammonium ion concentration (17.5 μg/ml) and increased pH was observed with 1% guar gum supplementation, which confirms augmented MICP activity of the bacterial strain. Microstructural analysis of microbial precipitation was performed using scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques, which confirmed the presence of calcium carbonate in different phases. Further, XRD and SEM based studies corroborated that guar gum supplemented media showed significant increase in stable calcite phase as compared to media without guar gum supplementation. Significant diverse group of nitrogenous compounds were observed in guar gum supplemented medium when subjected to Gas Chromatography–Mass spectrometry (GC-MS) profiling.

Low molecular weight polyethyleneimine conjugated guar gum for targeted gene delivery to triple negative breast cancer

The study emphasized on the development of an efficient, receptor-targeted non-viral gene delivery vehicle for gene therapy of triple negative breast cancer (TNBC). Here, naturally abundant guar gum based non-viral carrier was developed through conjugating by low molecular weight polyethylenimine (LPEI) (GNP) using napthalic anhydride coupling agent and characterized them by FT-IR, ¹H NMR, XRD and UV spectrophotometer. The carrier was found to be cytocompatible as revealed by MTT assay against MDA-MB-231 and HeLa cell lines and excellent blood compatibility till the concentration of 200 μg/ml. In addition to these, the carrier exhibited excellent gene binding capability and formed spherical shaped complexes. The carrier showed very high in vitro transfection efficiency in TNBC cell (MDA-MB-231) compared to lipofectamine 2000 (LF2k) which could be justified by its high buffering capacity. Therefore, GNP may be an attractive non-viral gene carrier for gene therapy of TNBC in future.