Synthesis of porous calcium-guar gum benzoate nano-biohybrids for sorptive removal of congo red and phosphates from water.

This work aims to develop an eco-sound nano-bio-hybrid sorbent using sustainable materials for sorptive elimination of congo red and phosphates from aquatic environment. An amphipathic biopolymer derivative, high DS guar gum benzoate (GGBN) was used for entrapment of as synthesized calcium carbonate nanoparticles using solvent diffusion nano-precipitation technique. Designer nano-biohybrids were developed upon experimenting with various materials stoichiometry. SEM, XRD and EDX studies confirmed near-uniform impregnation of rhombohedral calcium carbonate crystals throughout the biopolymer matrix. Average pore size distribution and surface area of final product Ca-GGBNC, were estimated from NDLFT and BET methods respectively. Analysis of adsorption findings acquired at study temperature 27 ± 2 °C showed that the maximum adsorption capacity of Ca-GGBNC recorded qmax, 333.33 mg/g for congo red azo dye and that for phosphate was at 500 mg/g. Adsorptive removal was noted and both components followed pseudo second order kinetics. Intra-particle diffusion kinetics investigation disclosed that the boundary layer effect was prominent and the adsorption rates were not solely directed by the diffusion stage. Activation energy, Ea was to be estimated using Arrhenius equation at 56.136 and 47.015 KJ/mol for congo red and phosphates respectively. The calculated thermodynamic parameters(ΔG°, ΔH°, and ΔS°) revealed the spontaneous, feasible and endothermic sorption process. Owing to active surface area, spherical size, functional moiety and porous network, antibacterial properties of nanobiohybrid were persistent and MIC against E. coli and S. aureus were recorded at 200 µg/mL and 350 µg/mL respectively.

Guar gum propionate-kojic acid films for Escherichia coli biofilm disruption and simultaneous inhibition of planktonic growth.

Nosocomial bacterial infections associated with biofilms inspire to explore newer bactericidal strategy with eco-friendly biomaterials as sustainable alternatives. In this research work, we successfully developed bio-safe films from kojic acid(KA) and guar gum propionate(GGP) for Escherichia coli biofilm disruption and planktonic cell killing. High DS(degree of substitution = 1.52) GGP was synthesized from guar gum (GG)assisted by chaotropic ions at room-temperature. Biopolymers were routinely characterized in CHN analyzer, FT-IR, TGA and XRD analysis. KA loaded GGP films were prepared by cross-linking the molecules in presence of epichlorhydrin and two different percentages of KA were employed. Film physical and tensile properties were systematically evaluated and optimized. Water vapour permeability (WVP) and tensile strength of final film GGPFK10 were recorded at 0.741 ± 0.09gmm-1kPa-1h-1 and 19.23 MPa. KA release from GGP matrix followed controlled diffusion process. MIC of GGP was 130 µg/mL and zone of inhibition of GGPFK10 was confirmed at 16.1 mm. SEM experiments disclosed the absence of pili-like structures with squeezed and elongated cellular morphology in dead planktonic cells. Disruption of biofilms was experimented in detail by CV assay, fluorescent, light microscopic and SEM studies. The film showed excellent cell-viability on human adult dermal fibroblast (HADF)cell-line. Overall, the biosafe film would be a potent antibacterial device for treating infections against E.coli biofilms and planktonic cells.

Newer guar gum ester/chicken feather keratin interact films for tissue engineering.

This work intends to synthesis newer guar gum indole acetate ester and design film scaffolds based on protein-polysaccharide interactions for tissue engineering applications. Guar gum indole acetate(GGIA) was synthesized for the first time from guar gum in presence of aprotic solvent activated hofmeister ions. The newer biopolymer was fully characterized in FT-IR,13C NMR, XRD and TGA analysis. High DS (Degree of Substitution, DS = 0.61) GGIA was cross-linked with hydrolyzed keratin, extracted from chicken feather wastes. Films were synthesized from different biopolymer ratios and the surface chemistry appeared interesting. Physicochemical properties for GGIA-keratin association were notable. Fully bio-based films were non-cytotoxic and exhibited excellent biocompatibility for human dermal fibroblast cell cultivations. The film scaffold showed 63% porosity and the recorded tensile strength at break was 6.4 MPa. Furthermore, the standardised film exerted superior antimicrobial activity against both the Gram-positive and Gram-negative bacteria. MICs were recorded at 130 µg/mL and 212 µg/mL for E. coli and S. aureus respectively. In summary, GGIA-keratin film scaffolds represented promising platforms for skin tissue engineering applications.

Fe3O4 coated guargum nanoparticles as non-genotoxic materials for biological application.

The current study aims to check various behavioural, developmental, cytotoxic, and genotoxic effects of Fe3O4-GG nanocomposite (GGNCs) on Drosophila melanogaster. Fe3O4 nanoparticles were prepared by the chemical co-precipitation method and cross-linked with guargum nanoparticles to prepare the nanocomposites. The nanocomposites were characterized by using transmission electron microscopy (TEM), X-ray diffraction (XRD), and FTIR techniques. To investigate the biomolecular interaction, GGNCs was further tagged with Fluorescein isothiocyanate. Various concentrations of nanocomposites were mixed with the food and flies were allowed to complete the life cycle. The life cycle of the flies was studied as a function of various concentrations of GGNCs. The 1st instar larvae after hatching from the egg start eating the food mixed with GGNCs. The 3rd instar larvae were investigated for various behavioural and morphological abnormalities within the gut. The 3rd instar larva has defective crawling speed, crawling path, and more number of micronuclei within the gut. Similarly, in adult flies thermal sensitivity, climbing behaviour was found to be altered. In adult flies, a significant reduction in body weight was found which is further correlated with variation of protein, carbohydrate, triglyceride, and antioxidant enzymes. Altogether, the current study suggests GGNCs as a non-genotoxic nanoparticle for various biological applications.

Guar gum cinnamate ouzo nanoparticles for bacterial contact killing in water environment.

Herein we report the synthesis of newer guar gum cinnamate esters (GGC) following a Hofmeister cation guided homogeneous phase reaction. High degree of substitution (DS) guar gum cinnamate was obtained using, cinnamic acid halide reactant at a 1:3 M ratio. The biopolymer was fully characterized in FT-IR,13C NMR, XRD and thermal analysis. Nanoparticles were further developed in a facile ouzo solvent diffusion technique. SEM studies confirmed quasi spherical shape of the nanoparticles (GGCN) with an average size of 200 nm. Nanoparticles GGCN, expressed antibacterial activity against water borne gram negative and gram positive bacteria. The MIC was recorded at 300 µg mL-1against Escherichia coli and 500 µg mL-1against Staphylococcus aureus. Bacterial contact killing was confirmed from the bacterial morphology studies in SEM. Thus, nanoparticles from GGC may be employed for bacterial killing and water decontamination.

Semi-interpenetrating hydrogels from carboxymethyl guar gum and gelatin for ciprofloxacin sustained release.

The present work reports the synthesis of new generation semi-interpenetrating (s-IPN) hydrogels from carboxymethyl guar gum (CMGG) and gelatin with enhanced gel properties for suitable drug delivery applications. Hydrogels are three dimensional polymer networks which respond to water and ion interactions. Irreversible s-IPN hydrogels were prepared by CMGG interactions in gelatin and characterized in FT-IR, SEM and thermal studies. CMGG was synthesized by Hofmeister ion guided homogeneous phase reactions. The swelling kinetics of the newer s-IPN hydrogels followed Schott's pseudo second order model. Furthermore, the hydrogels were hemocompatible, non-cytotoxic and appropriate for applications in physiological environment. Model drug ciprofloxacin was loaded within the hydrogels and the drug release was found to be a combination of both diffusion and hydrogel degradation. New generation s-IPN biopolymer hydrogels of carboxymethyl guar gum and gelatin holds promise for its application as sustained drug delivery device or alternatively as hydrogel sorbents for bio-toxins and molecules of biomedical importance.

Carboxymethyl guar gum synthesis in homogeneous phase and macroporous 3D scaffolds design for tissue engineering.

Guar gum (GG) is a galactomannan obtained directly from the Cyamopsis tetragonoloba seeds pericarb. The biopolymer hydrates hugely in three chain associated coil formations. Chaotropic Hofmeister ion like lithium interacts at the hydrogen bonding sites and render GG homogenization in polar solvents like dimethyl sulfoxide. This phenomenon was used for the first time for galactomannan derivatisations in homogeneous phase. Higher degree of substitution (DS) that was hereto unattainable in GG was achieved due to Hofmeister ion assisted assembly deformations. Furthermore, carboxymethyl guar gum (CMGG, DS = 1.10) blends well in poly-vinyl alcohol (PVA) at 2:1 mass ratio and enabled hydrophilic porous scaffold design for cell propagation. CMGG-PVA scaffolds porosity was 70-90% and the tensile strength was 6.32 MPa. CMGG-PVA scaffolds were useful as cell factories and in tissue engineering. New generation guar gum derivative scaffolds were non cytotoxic and permitted cell propagation in growth medium.

Guar gum benzoate nanoparticle reinforced gelatin films for enhanced thermal insulation, mechanical and antimicrobial properties.

This work relates to guar gum benzoate self assembly nanoparticles synthesis and nano composite films development with gelatin. Guar gum benzoate was synthesized in a Hofmeister cation guided homogeneous phase reaction. Self assembly polysaccharide nanoparticles were prepared in solvent displacement technique. Electron microscopy and DLS study confirmed uniform quasi spherical nanoparticles with ζ-potential - 28.7mV. Nanocomposite films were further developed in gelatin matrix. The film capacity augmenting due to nanoparticles incorporation was noteworthy. Superior barrier properties, reinforcing and thermal insulation effects were observed in films dispersed with 20% w/w nanoparticles. Detailed FTIR studies and thermal analysis confirmed nanoparticles interactions in the film matrix. The nanocomposite film water vapour permeability was at 0.75gmm-1kPa-1h-1, thermal conductivity 0.39Wm-1K-1 and the tensile strength were recorded at 3.87MPa. The final film expressed excellent antimicrobial properties against water born gram negative and gram positive bacteria.