Search

The graphene-based additives containing polyethyleneimine (PEI) or hydroxyapatite (HAP) were synthesized and their effects on the flame retardancy, thermal, mechanical properties of polyvinyl alcohol (PVA) matrix were evaluated. Thermogravimetric analysis studies (TGA) and Scanning electron microscope (SEM) images were indicated that PEI and HAP have a strong influence on the fire behavior of the composites which might be explained by the forming of a uniform and compact char during combustion. The presence of nitrogen in PEI and phosphorus in HAP which are generated nonflammable gases and phosphoric radicals, respectively at combustion conditions could represent a significant role in the catalytic char residue formation, heat transfer limitation and then diminish or even stop the combustion reactions. The char yields of the 5 wt% PVA/GO-PEI nanocomposites were increased up to 22 folds without any significant change in mechanical properties; Moreover, the char yield of PVA/GO-HAP nanocomposites was more than pure PVA (24 folds) because of its thermal stability at high temperature. All these data demonstrated that not only did PVA/GO-PEI keep the mechanical properties nearly the same as in pure PVA but also improved flame retardancy. But, the PVA/GO-HAP has great potential as flame retardants between all obtained composites. [ABSTRACT FROM AUTHOR]

Theranostics with the ability to simultaneous monitoring of treatment progress and controlled delivery of therapeutic agents has become as an emerging therapeutic paradigm in cancer therapy. In this study, we have developed a novel surface functionalized iron oxide nanoparticle using polyethyleneimine and glutathione for targeted curcumin (CUR) delivery and acceptable pH sensitive character. The developed magnetic nanoparticles (MNPs) were physicochemically characterized by FT-IR, XRD, FE-SEM and TEM. The MNPs was obtained in spherical shape with diameter of 50 nm. CUR was efficiently loaded into the MNPs and then in vitro release analyses were evaluated and showed that the prepared MNPs could release higher amount of CUR in acidic medium compared to neutral medium due to the pH sensitive property of the coated polymer. MTT assay confirmed the superior toxicity of CUR loaded MNPs compared to the control nanoparticles. Higher cellular uptake of the MNPs than negative control cells was demonstrated in SK-N-MC cell line. In vitro assessment of MRI properties showed that synthesized MNPs could be used as MRI imaging agent. Furthermore, according to hemolysis assay, the developed formulation exhibited suitable hemocompatibility. In vivo blood circulation analysis of the MNPs also exhibited enhanced serum bioavailability up to 2.5 fold for CUR loaded MNPs compared with free CUR. [ABSTRACT FROM AUTHOR]

A mild and efficient procedure for synthesis of benzimidazole derivatives in the presence of a catalytic amount of mechanochemically synthesized zinc oxide nanoparticles under solvent-free condition has been achieved. [image omitted] [ABSTRACT FROM AUTHOR]

A simple, efficient, and rapid method for high-yielding regioselective mono bromination of phenols and anilines has been achieved by treatment with N-bromasaccharin in the presence of a catalytic amount of tungstophosphoric acid. [ABSTRACT FROM AUTHOR]

An efficient, general procedure for reductive methylation of primary and secondary amines with 37% formaldehyde using N-methylpyrrolidine zinc borohydride (ZBHNMP) as a reducing agent gave the corresponding tertiary amines in excellent yields. The reaction was carried out in tetrahydrofuran under neutral conditions at 0-10 °C. [ABSTRACT FROM AUTHOR]

A variety of aliphatic and aromatic aldehydes and ketones were efficiently reduced to their corresponding amines when treated with primary and secondary amines and NaBH4 in micellar media at room temperature under neutral conditions. [ABSTRACT FROM AUTHOR]

Theranostics with the ability to simultaneous monitoring of treatment progress and controlled delivery of therapeutic agents has become as an emerging therapeutic paradigm in cancer therapy. In this study, we have developed a novel surface functionalized iron oxide nanoparticle using polyethyleneimine and glutathione for targeted curcumin (CUR) delivery and acceptable pH sensitive character. The developed magnetic nanoparticles (MNPs) were physicochemically characterized by FT-IR, XRD, FE-SEM and TEM. The MNPs was obtained in spherical shape with diameter of 50 nm. CUR was efficiently loaded into the MNPs and then in vitro release analyses were evaluated and showed that the prepared MNPs could release higher amount of CUR in acidic medium compared to neutral medium due to the pH sensitive property of the coated polymer. MTT assay confirmed the superior toxicity of CUR loaded MNPs compared to the control nanoparticles. Higher cellular uptake of the MNPs than negative control cells was demonstrated in SK-N-MC cell line. In vitro assessment of MRI properties showed that synthesized MNPs could be used as MRI imaging agent. Furthermore, according to hemolysis assay, the developed formulation exhibited suitable hemocompatibility. In vivo blood circulation analysis of the MNPs also exhibited enhanced serum bioavailability up to 2.5 fold for CUR loaded MNPs compared with free CUR.