Functional biocompatible magnetite-cellulose nanocomposite fibrous networks: Characterization by fourier transformed infrared spectroscopy, X-ray powder diffraction and field emission scanning electron microscopy analysis

Fabrication of octenyl succinic anhydride starch grafted with folic acid and its loading potential for doxorubicin hydrochloride

In this study, octenyl succinic anhydride (OSA) starch with different folic acid (FA) grafting time was prepared and the degree of FA substitution at different grafting time was determined. The results of XPS quantitatively reflected the surface elemental composition of OSA starch grafted with FA. FTIR spectra further confirmed the successful introduction of FA on OSA starch granules. SEM images showed that the surface roughness of OSA starch granules was more obvious with higher FA grafting time. The particle size, zeta potential, and swelling properties were determined to study the effect of FA on the structure of OSA starch. TGA indicated that FA effectively enhanced the thermal stability of OSA starch at high temperature. The crystalline form of the OSA starch gradually transformed from A type to a hybrid A and V-type with the progress of FA grafting reaction. In addition, the anti-digestive properties of OSA starch were enhanced after grafting FA. Using doxorubicin hydrochloride (DOX) as the model drug, the loading efficiency of OSA starch grafted with FA for DOX reached 87.71 %. These results provide novel insights into OSA starch grafted with FA as potential strategy for loading DOX.

Engineering of Superparamagnetic Core-Shell Iron Oxide/N-Chloramine Nanoparticles for Water Purification

In this study, we describe the synthesis and characterization of superparamagnetic core-shell iron oxide (IO)/N-halamine antibacterial nanoparticles (NPs). For this purpose, superparamagnetic IO core NPs were coated with cross-linked polymethacrylamide (PMAA) by surfactant-free dispersion copolymerization of methacrylamide and N,N-methylenebis(acrylamide) in an aqueous continuous phase. The effect of the polymerization process on the chemical composition, size, shape, crystallinity, and magnetic properties of the IO/PMAA NPs was elucidated. Conversion of the core-shell IO/PMAA NPs into their N-halamine form, IO/PMAA-Cl, was accomplished using a chlorination reaction with sodium hypochlorite. The influence of chlorination on the shape, crystallinity, and magnetic properties of the IO/PMAA NPs was studied. The IO/PMAA-Cl NPs demonstrated excellent antibacterial activity against Gram-negative and Gram-positive bacteria. Finally, the chlorination recharging capabilities of the NPs and their potential for use in the purification of water containing bacteria were demonstrated with magnetic columns packed with the IO/PMAA-Cl NPs.

Diphenylalanine peptide nanotubes self-assembled on functionalized metal surfaces for potential application in drug-eluting stent

This study focuses on the potential of diphenylalanine self-assembled peptide nanotubes (FF Nts) for delivery of flufenamic acid (FA) from metal implants. Self-assembly of FF Nts was studied in solution and on surfaces of glass, silicone and gold substrates. FA was loaded inside the shell of FF Nts and subsequently FF/FA Nts were attached to gold surfaces. The substrate were characterized by Field Emission Scanning Electron Microscopy (FESEM), fluorescence microscopy, confocal microscopy, and UV-vis spectroscopy. Release of FA from FF Nts were investigated by immersing coated metal substrates in phosphate-buffered saline for 12 days. Self-assembly of FF in water and solvent resulted in formation of nanotubes, which efficiently loaded 98% of FA with concentration of 20 µg/mL. FESEM images confirmed successful attachment of FF/FA Nts to functionalized gold substrates. In vitro release studies indicated using FF Nts has prolonged the release rate of FA for several days. Biocompatibility studied confirmed more than 50% of the cells were alive in concentration of 250-1000 µg/mL of FF Nts thus suggesting the potential of peptide based self-assemble nanostructures as an alternate system for polymer coating in drugs eluting stents. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2280-2290, 2016.

Cobalt ferrite nano-composite coated on glass by Doctor Blade method for photo-catalytic degradation of an azo textile dye Reactive Red 4: XRD, FESEM and DRS investigations

Cobalt ferrite nano-composite was prepared by hydrothermal route using cobalt nitrate, iron nitrate and ethylene glycol as chelating agent. The nano-composite was coated on glass by Doctor Blade method and annealed at 300 °C. The structural, optical, and photocatalytic properties have been studied by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and UV-visible spectroscopy (UV-Vis DRS). Powder XRD analysis confirmed formation of CoFe2O4 spinel phase. The estimated particle size from FESEM data was 50 nm. The calculated energy band gaps, obtained by Tauc relation from UV-Vis absorption spectra was 1.3 eV. Photocatalytic degradation of Reactive Red 4 as an azo textile was investigated in aqueous solution under irradiation showed 68.0% degradation of the dye within 100 min. The experimental enhanced activity compare to pure Fe2O3 can be ascribed to the formation of composite, which was mainly attributable to the transfer of electron and hole to the surface of composite and hinder the electron hole recombination.