Synthesis of Biodegradable Gum ghatti Based Poly(methacrylic acid-aniline) Conducting IPN Hydrogel for Controlled Release of Amoxicillin Trihydrate

Synthesis and characterization of novel guar gum based waste material derived nanocomposite for effective removal of hexabromocyclododecane and lindane

Herein, efficient degradation of hexabromocyclododecane (HBCD) and Lindane, a persistent organic pollutant using guar gum based calcium oxide doped silicon dioxide (GG-CaO@SiO2) has been reported. The nanocomposite was prepared by waste egg shell (CaO) and rice husk (SiO2) was well characterized. The maximum degradation of HBCD and Lindane were observed at 8 mg catalyst loading, neutral pH, and 2 mg L-1 of pollutant amount. The photocatalytic performance of GG-CaO@SiO2 for HBCD and Lindane photodegradation was evaluated, and it was found that the rate constant increased in the order of GG-CaO@SiO2 > CaO@SiO2 > GG. The polymeric GG-CaO@SiO2 nanocomposite showed maximum removal of both pollutants due to higher surface area (70 m2 g-1) and synergistic interactions among GG moieties. It achieved HBCD and Lindane elimination rates of 94 % and 90 % by photo-adsorptive degradation within 150 min. Meanwhile, the leaching of HBCD from expanded polystyrene (EPS) materials (0.14 ± 0.05 ppm) underwater with different time intervals and degradation of leachate HBCD were also assessed. The eradication of the pollutant manifested first-order kinetics, with the Langmuir adsorption. LC-MS analysis confirmed that GG-CaO@SiO2 effectively breaks down complex structure toxic pollutants into safer metabolites under natural sunlight exposure. The polymeric GG-CaO@SiO2 nanocomposite showed notable reusability up to ten cycle promotes sustainability.

Synthesis of Poly(GG-co-AAm-co-MAA), a Terpolymer Hydrogel for the Removal of Methyl Violet and Fuchsin Basic Dyes from Aqueous Solution

A novel adsorbent designated as terpolymer hydrogel (gellan gum-co-acrylamide-co-methacrylic acid) was prepared by free radical polymerization of gellan gum (GG), methacrylic acid (MAA), and acrylamide (AAm) using N,N-methylene bis-acrylamide (MBA) as cross-linker and ammonium per sulfate (APS) as the initiator of the reaction. The synthesized gel was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and thermogravimetric analysis (TGA) and was used for the adsorptive removal of methyl violet (MV) and Fuchsin Basic (FB) dyes from aqueous solution. The effect of temperature, contact time, pH, and concentration on them under the study adsorption process was evaluated. Freundlich isotherm and pseudo-second-order kinetic models were found to be best in fitting the isothermal and kinetics data. The water diffusion and % swelling of hydrogel were studied at various pH in distilled water and at neutral pH in tap water. The diffusion was found to be of Fickian type with a maximum swelling of 5132%. The maximum adsorption capacity was 233 mg/g against MV and 200 mg/g against FB dyes. The swelling and adsorption were pH dependent and increased with increase in pH. The enthalpy, Gibbs free energy, and entropy changes of adsorption for both the dyes indicated the adsorption process to be exothermic, feasible, and spontaneous. The hydrogel was successfully regenerated using acetone and distilled water for five cycles and still, its dye removal efficiency was 80% of its original value. The poly(GG-co-AAm-co-MAA) hydrogel successfully removed the selected dyes from water and could thus be used as an efficient alternative sorbent for cationic dye removal from aqueous solutions.

Synthesis of GG-g-P(NIPAM-co-AA)/GO and evaluation of adsorption activity for the diclofenac and metformin

The grafting of biopolymer gum ghatti (GG) over the PNIPAM and PAA was done and loaded with graphene oxide (GO). Aim of this work is carried out combine adsorption of sodium diclofenac (SD) and metformin (MF) by the prepared hydrogels under influence of various parameters. The adsorbent GG-g-P(NIPAM-co-PAA)/GO(3 mg) chosen for adsorption activity as it displayed highest swelling capacity. The effect of amount of both adsorbents GG-g-P(NIPAM-co-PAA and GG-g-P(NIPAM-co-PAA)/GO(3 mg) showed that highest adsorption capacity found at 40 mg of adsorbents for both drugs at conditions: 100 mg/L concentration, 30 °C, 24 h and pH 6 and subsequently became stable. Both the drugs were removed in greater amount at 25 mg/L concentration, 24 h of contact time, 30 °C, 40 mg amount of both adsorbents and pH 6. Effect of time revealed that as time elevated from 2 h to 12 (100 mg/L concentration,, 30 °C, 40 mg amount of both adsorbents and pH 6) led to increase adsorption efficiency and after that increase time did not much impact on adsorption activity. Adsorption activity of hydrogels declined with increase of temperature (100 mg/L concentration, 12 h, 40 mg amount of both adsorbents and pH 6). The acidic conditions favored adsorption of SD while MF adsorbed under the weak acidic(100 mg/L concentration, 30 °C, 12 h, 40 mg amount of both adsorbents). However, basic conditions did not much influence on adsorption of MF but effected on adsorption activity of SD. Adsorption isotherm and kinetic model suggested that adsorption is homogenous and chemical in nature. The maximum adsorption capacity (qm) found to be 289.01 and 154.55 mg/g for SD and MF respectively.

Graphical abstract

Supplementary information

The online version contains supplementary material available at 10.1007/s40201-023-00867-w.

Carboxymethyl cellulose based sustainable hydrogel for colon-specific delivery of gentamicin

The current research includes the synthesis, improvement of NaCMC-cl-DMAA/AAc hydrogel and in-situ controlled release of gentamicin within various pH environments. The prepared hydrogel was then modified using boron nitride nanosheets aiming to enhancement in the adsorption rate. The prepared hydrogels were investigated by FTIR, XRD, FESEM, TGA/DSC, swelling and cell viability analysis. Cytotoxicity study indicated that prepared sample has a cytocompatibility nature towards healthy normal human cell line (FR2 cells). By changing the pH environment, the drug release properties of the hydrogels can be controlled. The cumulative rate of release for NaCMC-cl-DMAA/AAc hydrogel was 76.5 % at pH = 2.2 and 87.5 % at pH = 7.4. Whereas drug release rate for NaCMC-cl-DMAA/AAc-BNNSs hydrogel composite was 78.6 % at pH = 2.2 and 97.3 % at pH = 7.4 within 4320 min. Gentamicin release kinetics have been determined using the Korsemeyar-Peppas model, which confirms the drug release mechanism.

The effect of oxygen plasma pretreatment on the properties of mussel-inspired polydopamine-decorated polyurethane nanofibers

In this study, polyurethane (PU) scaffolds were fabricated by electrospinning technology and modified through the deposition of polydopamine (PDA) on the activated surface under oxygen plasma treatment. Herein, the effect of the modification process on the homogeneous surface coating and the changes in the physicochemical and biological properties were evaluated. Morphological observations demonstrated decoration of the nanofibrous microstructure with PDA, while the uniformity and homogeneity of the deposited layer increased after plasma oxygen treatment. Hydrophilicity measurements and swelling ratio indicated a remarkable improvement in the interaction of scaffolds with water molecules when the PDA coating is applied on the surface of the treated nanofibers. The biomineralization of the samples was characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) images. It was found that PDA has the capability for mineralization, and the amount of deposited hydroxyapatite increased as a function of PDA content. The in vitro evaluation of constructs indicated great improvement in cell-scaffold interactions, biocompatibility, and alkaline phosphatase activity after coating the PDA on the plasma-modified matrix. These results suggest that PDA coating, especially after oxygen plasma treatment, improves the physicochemical and in vitro properties of PU scaffolds for bone tissue engineering application.

Neem gum based pH responsive hydrogel matrix: A new pharmaceutical excipient for the sustained release of anticancer drug

The present research work was aimed to synthesize neem gum-based site-specific drug delivery device for anticancer drug methotrexate at different pH condition. The hydrogel-based drug delivery device was synthesized by optimizing reaction parameters using a factorial design approach response surface method. This model comprised of various sets of reactions with varying concentrations of solvent, crosslinker, initiator and monomer under microwave radiation. Characterization of the candidate hydrogel was done using UV-visible spectrophotometer, FTIR, SEM, Raman, and XRD techniques. The release profile of the hydrogels network was studied through a methotrexate under different pH conditions. The drug encapsulation capacity was found to be around 93% and 90% in pH 7.4 and 6.8. Drug release through the synthesized hydrogel matrix was found to show non-Fickian behaviour at each medium. The hydrogel network showed less release in pH 6.8 than pH 7.4, suggesting that hydrogels may be suitable drug carriers for release of anticancer drug delivery system. Hemolysis testing was also done to check the compatibility of the synthesized drug delivery device with the four different blood samples. Hemolysis was found to be less than 1% in the case of all blood groups, which indicates that the synthesized candidate polymers are biocompatible with all blood groups.

One-pot green synthesis of polymeric nanocomposite: Biodegradation studies and application in sorption-degradation of organic pollutants

The research work proposes the synthesis of a nanocomposite hydrogel which is a dual combination of binary interpenetrating network (BIPN) and bismuth ferrite nanoparticles. BIPN synthesized from binary graft copolymer (BGC) used as starting material. The cross-linked network of BGC is interpenetrating the newly synthesized cross-linked network of poly(acrylic acid) and the product is named as BIPN. Binary graft copolymer had been synthesized from grafting of guggul aqueous extract with copolymeric chains of acrylamide (primary monomer) and acrylic acid (secondary monomer) crosslinked by N,N'-methylene bisacrylamide (MBA). The maximum percentage swelling was evaluated for BGC through optimization of various reaction parameters: amount of water, binary ratio of acrylamide to acrylic acid, concentrations of MBA, ammonium persulphate, pH, temperature and time. Considering pre-optimized parameters for BGC synthesis, BIPN formation required optimization of only acrylic acid. Maximum percentage swelling obtained was 1497.79% and 308.15% for BGC and BIPN, respectively. Maximum percentage biodegradation of 90.64% and 82.38% were calculated for BGC and BIPN, respectively using composting method. Degradation efficiency of brilliant blue (BB) and fuchsin basic (FB) dyes was in the order: Nanocomposite ≫ BIPN > BGC. Maximum percentage degradation observed in case of nanocomposite was 94.1% and 99.3% in sunlight for BB and FB, respectively. The interaction of dyes with the nanocomposite involved mainly ionic interactions. The adsorption models Freundlich and Langmuir were applicable to overall adsorption and degradation process of BB and FB, respectively. Maximum adsorption capacities corresponding to minimum concentration i.e. 10 mg L^-1 for BB and FB were calculated as 0.409 mg g^-1 and 0.439 mg g^-1, respectively. Second order and first order kinetics were found to be suitable for BB and FB adsorption-degradation pathways, respectively. Intraparticle diffusion mechanism was favorable to both dyes and adsorption followed three steps. Gas chromatography coupled with mass spectrometric analysis could give the degraded products which was helpful in drawing degradation pathway. The degradation process involved active radical species (O₂^-., OH^.) and they carry out oxidation-reduction reactions on dyes to give decolorized solution containing mineral ions.

Tree gum-based renewable materials: Sustainable applications in nanotechnology, biomedical and environmental fields

The prospective uses of tree gum polysaccharides and their nanostructures in various aspects of food, water, energy, biotechnology, environment and medicine industries, have garnered a great deal of attention recently. In addition to extensive applications of tree gums in food, there are substantial non-food applications of these commercial gums, which have gained widespread attention due to their availability, structural diversity and remarkable properties as 'green' bio-based renewable materials. Tree gums are obtainable as natural polysaccharides from various tree genera possessing exceptional properties, including their renewable, biocompatible, biodegradable, and non-toxic nature and their ability to undergo easy chemical modifications. This review focuses on non-food applications of several important commercially available gums (arabic, karaya, tragacanth, ghatti and kondagogu) for the greener synthesis and stabilization of metal/metal oxide NPs, production of electrospun fibers, environmental bioremediation, bio-catalysis, biosensors, coordination complexes of metal-hydrogels, and for antimicrobial and biomedical applications. Furthermore, polysaccharides acquired from botanical, seaweed, animal, and microbial origins are briefly compared with the characteristics of tree gum exudates.

Antioxidant activity and controlled drug delivery potential of tragacanth gum-cl- poly (lactic acid-co-itaconic acid) hydrogel

Tragacanth gum-cl-poly (lactic acid-co-itaconic acid) (TG-cl-p(LA-co-IA)) hydrogel is synthesized through graft copolymerization reaction using microwave assisted technique. The synthesized hydrogel was characterised using various analytical and characterization techniques such as FTIR, FESEM, XRD, TGA, TEM and SEM. It was observed that, the maximum percentage swelling (P_s) of the hydrogel was 311.61% after 6h at room temperature and 298.06% after 3h at 60°C and TG-cl-p(LA-co-IA) exhibited highest Amoxicillin loading (73%) in double distilled waterafter 24h. From the controlled release studies, it was evident that maximum drug release of about 96% took place at pH 2.2=after 6h. The synthesized hydrogel also showed mild antioxidant properties and 43.85% of free radical scavenging was occurred at a concentration of 640μg/mL and hence it can be effectively used to reduce the oxidative stresses. In addition to this, the antibacterial studies also showed that it is more effective against S. aureus.

Effects of superabsorbent polymers on the fate of fungicidal carbendazim in soils

Superabsorbent polymers (SAPs) have been extensively used as soil amendments to retain water, and they often coexist with pesticides in agricultural fields. However, effects of SAPs on the fate of pesticides in soil remain poorly understood. In this study, a laboratory experiment was conducted to evaluate the effects of SAPs on the transformation of ¹⁴C-carbendazim in soils. The results showed that compared to the SAPs-free control, 11.4% relative reduction of ¹⁴C-carbendazim extractable residue was observed in red clayey soil with SAPs amendment after 100days of incubation (p<0.05). Carbendazim dissipation was enhanced by 34.7%, while no obvious difference was found in loamy soil and saline soil (p>0.05). SAPs changed the profiles of major metabolites (2-aminobenzimidazole and 2-hydroxybenzimidazole) to some extent. After 100days of SAPs treatment, the mineralization of ¹⁴C-carbendazim was significantly reduced by 37.6% and 41.2% in loamy soil and saline soil, respectively, relative to the SAPs-free treatment (p<0.05). SAPs increased the bound residue of carbendazim by 11.1-19.1% in comparison with SAPs-free controls. These findings suggest SAPs amendments significantly affected the fate of carbendazim and attention should be given to the assessment of environmental and ecological safety of pesticides in SAPs-amended soils.

Controlled release of antibiotic amoxicillin drug using carboxymethyl cellulose-cl-poly(lactic acid-co-itaconic acid) hydrogel

In this paper, microwave assisted preparation of carboxymethyl cellulose-cl-poly(lactic acid-co-itaconic acid) (CMC-cl-P(LA-co-IA)) hydrogel was reported via facile graft copolymerization using N,N¹-methylene-bis-acrylamide (MBA) and potassium persulphate as cross linker and initiator. Different reaction parameters were optimized to achieve good yield. The formation of hydrogel was confirmed by characterization techniques such as Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, thermo gravimetric analysis, transmission electron microscopy etc. The antimicrobial activities of the hydrogel were studied against Staphylococcus aureus and Escherichia coli. About 95% killing of bacteria was recorded after 24h. The controlled release of amoxicillin drug from hydrogel was evaluated as a function of pH and time. Maximum drug release of 98% was recorded at 2.2 pH after 7h. The kinetic studies showed non-Fickian diffusion of the drug.

Polymeric nanobiocomposites for biomedical applications

Polymeric nanobiocomposites have recently become one of the most essential sought after materials for biomedical applications ranging from implants to the creation of gels. Their unique mechanical and biological properties provide them the ability to pass through the highly guarded defense mechanism without undergoing noticeable degradation and initiation of immune responses, which in turn makes them advantageous over the other alternatives. Aligned with the advances in tissue engineering, it is also possible to design three-dimensional extracellular matrix using these polymeric nanobiocomposites that could closely mimic the human tissues. In fact, unique polymer chemistry coupled with nanoparticles could create unique microenvironment that promotes cell growth and differentiation. In addition, the nanobiocomposites can also be devised to carry drugs efficiently to the target site without exhibiting any cytotoxicity as well as to eradicate surgical infections. In this article, an effort has been made to thoroughly review a number of different types/classes of polymeric nanocomposites currently used in biomedical fields. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1241-1259, 2017.

Preparation and characterization of a novel superabsorbent of konjac glucomannan-poly(acrylic acid) with trimethylolpropane trimethacrylate cross-linker

A novel superabsorbent was prepared by the solution polymerization of partially neutralized acrylic acid onto konjac glucomannan using potassium persulfate as a free radical initiator and trimethylolpropane trimethacrylate as a crosslinking agent.

Eco-friendly superabsorbent composite based on sodium alginate and organo-loess with high swelling properties

A novel superabsorbent composite with high swelling properties was synthesized by the grafted co-polymerization of partially neutralized acrylic acid (AA) onto a sodium alginate (NaAlg) backbone in the presence of organo-loess.