Guar gum/poly ethylene glycol/graphene oxide environmentally friendly hybrid hydrogels for controlled release of boron micronutrient.

The present study was aimed at synthesis of polymeric hydrogels for controlled boron (B) release, as B deficiency is a major factor that decreases crops yield. Thus, graphene oxide incorporated guar gum and poly (ethylene glycol) hydrogels were prepared using the Solution Casting method for boron release. 3-Glycidyloxypropyl trimethoxysilane (GLYMOL) was used as a cross-linker. Characterizations of hydrogels were carried out by Fourier Transform Infrared Spectroscopy (FTIR), Thermo-Gravimetric Analysis and Scanning Electron scope. The FTIR outcomes confirmed the existence of functional groups, bindings and development of hydrogel frameworks from incorporated components. The quantity of GLYMOL directly increased the thermal stability and water retention but decreased the swelling %. The maximum swelling for the hydrogel formulations was observed at pH 7. The addition of GLYMOL changed the diffusion from quasi-Fickcian to non-Fickcian diffusion. The maximum swelling quantities of 3822% and 3342% were exhibited by GPP (control) and GPP-8 in distilled water, respectively. Boron release was determined in distilled water and sandy soil by azomethine-H test using UV-Visible spectrophotometer while 85.11% and 73.65% boron was released from BGPP-16, respectively. In short, water retentive, water holding capacities, swelling performances, biodegradability and swelling/deswelling features would offer an ideal platform for boron release in sustained agricultural applications.

In-house fabrication of macro-porous biopolymeric hydrogel and its deployment for adsorptive remediation of lead and cadmium from water matrices.

A novel adsorbent was prepared by blending chitosan (CS) and acrylic acid (AA) while using formaldehyde as a cross linker in the form of hydrogel beads. The adsorption properties of these hydrogel beads for the removal of toxic metal ions (Pb2+ and Cd2+) from aqueous solutions were evaluated. The hydrogel beads have a 3D macro-porous structure whose -NH2 groups were considered to be the dominant binding specie for Cd and Pb ions. The equilibrium adsorption capacity (qe) of beads was significantly affected by the mass ratio of sorbent and sorbate. The percentage removal of Cd and Pb ions was observed to be enhanced with the increase in sorbate concentration. The hydrogel beads maintained good adsorption properties at adsorption-desorption equilibrium. The Langmuir and Freundlich models were used to elaborate the isotherms as well as isotherm constants. Adsorption isothermal data is well explained by the Freundlich model. The data of experimental kinetics is interrelated with the second-order kinetic model, which showed that the chemical sorption phenomenon is the rate limiting step. The results of intraparticle diffusion model described the adsorption process occurred on a porous substance that proved chitosan/Formaldehyde beads to be the favorable adsorbent.

Kinetics and controlled release of lidocaine from novel carrageenan and alginate-based blend hydrogels.

The controlled release of drug from drug carrier has been a point of concern for the researchers to ensure the bioavailability of drug with reduced side effects. The formulation in this study is based upon biopolymers; carrageenan (CG), sodium alginate (SA) and various molecular weights of polyethylene glycol (PEG), cross-linked with (3-Aminopropyl)triethoxysilane, APTES for the sustained release of model drug (lidocaine). The physicochemical properties of the formulated hydrogel blends include bonding pattern (using Fourier Transform Infra-Red Spectroscopy (FTIR), Thermogravimetric analysis (TGA), X-ray diffraction (XRD), swelling study, antimicrobial activity and morphology of hydrogel films was analyzed by scanning electron microscopy (SEM). The as-prepared hydrogels show an improved cell compatibility against 3T3 cell line as well as cell proliferation and kinetics of drug release showed that these hydrogels are potential for controlled release of lidocaine, a numbing agent. GAP 60 exhibited maximum swelling percent (910%) and was employed to load the drug. By using in vitro model, the drug release was studied in PBS solution. Non-Fickian and other kinetic models (Zero order, Higuchi, Hixson, Korsmeyer Peppas and Baker-Lonsdale) for diffusion were followed in results. The improved properties showed that the formulated hydrogels can easily be used for the sustain drug release studies.

Loading of Cefixime to pH sensitive chitosan based hydrogel and investigation of controlled release kinetics.

Chitosan (biopolymer) and polyvinyl pyrolidone (PVP) with aminopropyletriethoxy silane (cross linker) based hydrogels were prepared and tested for controlled drug release. The drug release and kinetics were studied as a function of pH. Formulations were characterized by Fourier Transform Infrared (FTIR) and Thermogravimetric (TGA) analysis and TAP 32 hydrogel formulation was the most stable and hydrogel samples showed promising antibacterial activity against E. coli strain. The maximum swelling (4386%) was observed for TAP 32 formulation in distilled water, which was decreased with the concentration of ions. The diffusion exponent (n) values of all hydrogel formulations were recorded to be <0.5, which is an indication of Quasi-Fickian diffusion. The maximum swelling was observed at pH 2 and decreased at higher pH. The pH sensitivity of hydrogels found to be promising for their use in drug delivery, which was tested for cefixime drug. Drug release of 81.6% was observed for the period of 12 h in a simulated gastric fluid (SGF). The values of R2 for zero order, first order, Higuchi, Hixson, Korsmeyer-Peppas and Baker-Lonsdale were 0.97, 0.9818, 0.99, 0.99, 0.88 and 0.80, respectively. The hydrogels based on chitosan and PVP revealed potential for controlled cefixime drug release in gastric pH medium.