pH-controlled drug release of radiation synthesized graphene oxide/(acrylic acid-co-sodium alginate) interpenetrating network

E-beam irradiation-induced synthesis of hydroxyethyl cellulose/(Cu2O-rGO)/BiVO4-based nanocomposite for photocatalytic remediation of wastewater under visible light

Using E-beam irradiation as an eco-friendly technique for initiation and crosslinking, a series of Hydroxyethyl Cellulose-poly vinyl alcohol copolymer hydrogels were synthesized as templates for cuprous oxide (Cu2O), reduced graphene oxide (rGO) and bismuth vanadate (BiVO4) nanoparticles to be used as nanocomposites photocatalysts for methylene blue (MB) dye decolorization using visible light. Preparation conditions were optimized to ensure the construction of a good network architecture and therefore the highest gelation degree. For the preparation of (Cu2O@rGO)/BiVO4 nanocomposites, a series of rGO was decorated by Cu2O using the precipitation method, followed by mixing with BiVO4 which was synthesized hydrothermally. (EDX), (XRD), (TEM), and (SEM) were used for nanoparticle characterization. The thermal characteristics of the fabricated nanocomposites were evaluated using thermal gravimetric analysis. The presence of rGO enhanced the decolorization efficiency of MB about 20 % higher than that of (HEC-PVA)/Cu2O which achieves only (59 %) decolorization efficiency. After the addition of BiVO4 NPs, the decolorization efficiency increased to reach 90 % after 150 min at pH 11 using a 10 ppm MB solution. The developed (HEC-PVA)/(Cu2O@rGO)/BiVO4 photocatalyst exhibits efficient reusability for 5 cycles. Treated dyed water shows a germination index (GI) of 82 % suggesting its suitability for irrigation of playgrounds and gardens.

A Review on Synthesis Methods of Phyllosilicate- and Graphene-Filled Composite Hydrogels

This review discusses, in brief, the various synthetic methods of two widely-used nanofillers; phyllosilicate and graphene. Both are 2D fillers introduced into hydrogel matrices to achieve mechanical robustness and water uptake behavior. Both the fillers are inserted by physical and chemical gelation methods where most of the chemical gelation, i.e., covalent approaches, results in better physical properties compared to their physical gels. Physical gels occur due to supramolecular assembly, van der Waals interactions, electrostatic interactions, hydrophobic associations, and H-bonding. For chemical gelation, in situ radical triggered gelation mostly occurs.

Graphene oxide-ellagic acid nanocomposite as effective anticancer and antimicrobial agent

In this study, ellagic acid (ELA), a skin anticancer drug, is capped on the surface(s) of functionalised graphene oxide (GO) nano-sheets through electrostatic and π-π staking interactions. The prepared ELA-GO nanocomposite have been thoroughly characterised by using eight techniques: Fourier-transform infrared spectroscopy (FTIR), zeta potential, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy, atomic force microscopy (AFM) topographic imaging, transmission electron microscopy (TEM), and surface morphology via scanning electron microscopy (SEM). Furthermore, ELA drug loading and release behaviours from ELA-GO nanocomposite were studied. The ELA-GO nanocomposite has a uniform size distribution averaging 88 nm and high drug loading capacity of 30 wt.%. The in vitro drug release behaviour of ELA from the nanocomposite was investigated by UV-Vis spectrometry at a wavelength of λ_max 257 nm. The data confirmed prolonged ELA release over 5000 min at physiological pH (7.4). Finally, the IC₅₀ of this ELA-GO nanocomposite was found to be 6.16 µg/ml against B16 cell line; ELA and GO did not show any cytotoxic effects up to 50 µg/ml on the same cell lines.

Radiation development of pH-responsive (xanthan-acrylic acid)/MgO nanocomposite hydrogels for controlled delivery of methotrexate anticancer drug

Nanocomposite hydrogels composed of magnesium oxide (MgO) and natural polymer-based copolymer of Xanthan gum (Xan) and acrylic acid (AAc) were prepared using radiation-induced copolymerization and crosslinking technique to be used as a drug delivery system. MgO nanoparticles were synthesized using sol- gel method. FTIR, XRD, UV-vis and TEM analysis revealed the successful preparation of MgO nanoparticles. The size of MgO nanoparticles was found to be 6.6 nm. FTIR data confirmed the incorporation of MgO within the (Xan-AAc) copolymer hydrogel. The presence of MgO nanoparticles slightly decreases the gelation degree and on contrary the swelling degree and network porosity was enhanced. (Xan-AAc)/MgO nanocomposites show typical pH-dependent swelling behavior Moreover, the swelling kinetics showed that all the samples under investigation possess Fickian at pH1 and non-Fickian at pH7. Methotrexate (MTX) as model for anticancer drugs was used to evaluate the potential efficiency of the obtained (Xan-AAc)/MgO nanocomposites as drug carrier. Incorporation of MgO into (Xan-AAc) hydrogel improves the drug loading efficiency and enhances the (MTX) release to reach maximum in the simulated intestine medium (pH7). The drug release profile came in a good agreement with swelling results which recommend the (Xan-AAc)/MgO nanocomposite hydrogels as potential targeted drug delivery system.