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Nanohydrogels (NHs) are novel and attractive carriers for various anticancer factors delivery. The objective of present study is development of a safe NH for pH responsive delivery of methotrexate (MTX). Herein, poly (hydroxyethyl methacrylate) is utilized as the main structure, which is cross-linked with poly(ethyleneglycol) diacrylate (PEG-DA) through reversible addition fragmentation chain transfer polymerization technique. After synthesis, the developed structure is characterized using different methods, including 1H NMR, FT-IR, size exclusion chromatography, transmission electron microscopy and dynamic light scattering. The results confirm successful synthesis of the NH with acceptable yield and nano scale mean size of 194 nm. Methotrexate is conjugated with the aforementioned structure through pH responsive esteric bond. The efficiency of the prepared NH in loading and release of the anticancer drug, methotrexate, is tested. The developed NH shows great potential in methotrexate loading, as well as a faster release rate of methotrexate in acidic pH. The results of in vitro toxicity assessment on MCF-7 as a breast cancer cell line reveal an improved cytotoxicity induction by the methotrexate loaded particles when compared with the free MTX molecules. The suitable size (

The advent of smart nanohydrogel has revealed new opportunities for scientists to develop the most efficient anti-cancer vehicles with safe and biocompatible profile. In this experiment, using reversible addition-fragmentation chain transfer polymerization method as a novel, safe and smart pH responsive formulation of poly (hydroxyethyl methacrylate-co-N,N-dimethylaminoethyl methacrylate) and poly (ethylene glycol)-diacrylate as cross-linker were synthesized. The synthesized structure was confirmed by Fourier-transform infrared spectroscopy and proton nuclear magnetic resonance methods. The pH responsive behavior of the synthesized particles was checked by size measurement in two different pH values (5.5 and 7.4) by dynamic light scattering and transmission electron microscopy. The prepared structure had nanometer sizes of 180 in medium with pH of 7.4, when it encountered acidic medium (e.g. pH 5.5), the particles swelled to about 400 nm. The efficiency of the prepared pH responsive nanohydrogels was tested as a drug delivery system. An anti-cancer drug, doxorubicin successfully interacted with this material. The release profiles of nanoparticles carrying drug molecules were checked in two different simulated pH of healthy organs (7.4) and tumor site (5.5). Despite lower release in pH of 7.4 (∼20%), an increased drug release of 80% was obtained in pH of 5.5. The in vitro toxicity assay, apoptosis evaluation and uptake experiments were performed on breast cancer cell line (MCF-7), which showed a time dependency cellular entrance, an enhanced cytotoxicity and apoptosis induction by the doxorubicin loaded nanoparticles. Hemolysis assays confirmed the safety and hemocompatibility of the developed nanohydrogel. The suitable size (200 nm), pH responsive behavior, anti-proliferative activity and apoptosis induction in cancer cells and hemocompatibility were the noticeable features of the developed doxorubicin adsorbed nanoparticle, which introduced this formulation as an ideal vehicle in anti-cancer drug delivery.

The effect of the preparation method on the structural properties and activity of Ni–Co catalysts in the Fischer–Tropsch synthesis has been explored. Impregnation, co-precipitation and a novel method, thermal decompositions of inorganic precursor complex, procedures were applied for the generation of the Ni-promoted alumina- or silica-supported cobalt catalysts. The precursors and the catalysts that were obtained from their calcination were characterized by powder X-ray diffraction, thermal gravimetric analysis, Brunauer–Emmett–Teller specific surface area measurements, scanning electron microscopy and Fourier transform infrared spectroscopy. The catalytic performance in Fischer–Tropsch synthesis was investigated for all calcined catalysts in the temperature interval from 280 to 360 °C. The Ni–Co/Al2O3 catalyst prepared by thermal decomposition of [Ni(H2O)6][Co(dipic)2]·2H2O/Al2O3 as a precursor performed optimally for the conversion of synthesis gas to light olefins. The outcomes revealed that this novel procedure is more advantageous than impregnation and co-precipitation methods for the preparation of effective and durable cobalt catalysts for Fischer–Tropsch synthesis.

The influence of three preparation methods on the properties and reaction performances of a titania-supported Mn–Cr bimetallic nanocatalyst for high-temperature water–gas shift reaction has been studied. Impregnation, co-precipitation and thermal decomposition of the [Mn(H2O)6]3[Cr(NCS)6]2·H2O/TiO2 precursor as an inorganic precursor complex were utilized for the preparation of the Mn–Cr/TiO2 catalysts. The calcined catalyst and the precursor that were used for its preparation were characterized by powder X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller specific surface area measurements, thermal gravimetric analysis, differential scanning calorimetry and Fourier transform–infrared spectroscopy. The high-temperature water–gas shift activity was appraised in the temperature range from 280 to 420 °C. The results showed that thermal decomposition of inorganic precursor complexes is more advantageous than impregnation and co-precipitation methods for the preparation of Mn–Cr/TiO2 catalysts for high-temperature water–gas shift reaction.

Three new thiourea ligands derived from the condensation of aroyl- and aryl-isothiocyanate derivatives with 2,6-diaminopyridine, named 1,1'-(pyridine-2,6-diyl)bis(3-(benzoyl)thiourea) (L1), 1,1'-(pyridine-2,6-diyl)bis(3-(2-chlorobenzoyl)thiourea) (L2) and 1,1'-(pyridine-2,6-diyl)bis(3-(4-chlorophenyl)thiourea) (L3), their oxido-vanadium(IV) complexes, namely [VO(L1('))(H2O)] (C1), [VO(L2('))(H2O)] (C2) and [VO(L3('))(H2O)] (C3), and also, dioxo-vanadium(V) complex containing 4-hydroxy-2,6-pyridine dicarboxylic acid (chelidamic acid, H2dipic-OH) and metformin (N,N-dimethylbiguanide, Met), named [H2Met][VO2(dipic-OH)]2·H2O (C4), were synthesized and characterized by elemental analysis, FTIR and (1)H NMR and UV-visible spectroscopies. Proposed structures for free thiourea ligands and their vanadium complexes were corroborated by applying geometry optimization and conformational analysis. Solid state structure of complex [H2Met][VO2(dipic-OH)]2·H2O (triclinic, Pī) was fully determined by single crystal X-ray diffraction analysis. In this complex, metformin is double protonated and acted as counter ion. The antibacterial properties of these compounds were investigated in vitro against standard Gram-positive and Gram-negative bacterial strains. The experiments showed that vanadium(IV) complexes had the superior antibacterial activities than novel thiourea derivatives and vanadium(V) complex against all Gram-positive and Gram-negative bacterial strains.

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