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A novel nanocomposite of colloidal gold (GNPs) and hydroxyapatite nanotubes (Hap) was prepared for immobilization of a redox protein, hemoglobin (Hb), on glassy carbon electrode. The immobilized Hb showed fast direct electron transfer and excellent electrocatalytic behavior toward reduction of hydrogen peroxide. A synergic effect between GNPs and Hap for accelerating the surface electron transfer of Hb was observed, which led to a pair of redox peaks with a formal potential of (À 340 AE 2) mV at pH 7.0, and a new biosensor for hydrogen peroxide with a linear range from 0.5 to 25 mM and a limit of detection of 0.2 mM at 3s. Owing to the good biocompatibility of the nanocomposite, the biosensor exhibited good stability and acceptable reproducibility. The as-prepared nanocomposite film provided a good matrix for protein immobilization and biosensor preparation.

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This study is to prepare a nanosuspension based on poly(lactic‐co‐glycolic acid) (PLGA) for delivery, controlled release and enhanced anti‐solid tumor effects of As2O3. As2O3‐loaded PLGA nanocapsules (As2O3‐PLGA NCs) were prepared by double emulsion‐solvent evaporation method and were optimized by univariate analysis in combination with orthogonal experimental according to several factors. The optimized As2O3‐PLGA NCs presented suitable physical stability, favorable size of (200.2±10.6) nm (PDI=0.117±0.008), spherical shape, and high encapsulation efficiency (92.48%±2.14%). The in vitro suspension stability of the NCs was excellent. The release of As2O3 from the NCs showed pH responsive release characteristics. The NCs can be efficiently taken up by SMMC‐7721 cell and showed excellent antitumor efficacy against SMMC‐7721 cell line. Then, As2O3‐PLGA NCs could be considered as a promising formulation for the pH dependent release of As2O3 in cancer cells and enhance the anti‐solid tumor effects of As2O3.

Analytical comparison between unprepared and calcined magnetitum (Cishi) Abstract The phases, chemical composition, surface appearance, crystal size, specific surface and thermal behavior of the unprepared and calcined forms of the mineral Magnetitum (Cishi), used as Chinese traditional medicine, were characterized by using X-ray powder diffraction, scan electron microscopy, inductively coupled plasma-atomic emission spectometry (ICP) and thermogravimetric (TG). The results indicated that after calcination the main phase Fe 3 O 4 of the calcined Magnetitum (Duan Cishi) remained, while the Fe 2 O 3 phase disappeared. The contents of the harmful chemical elements Cd and Pb were obviously reduced, while the crystal size increased from 24.5 to 35.7 nm and surface loosened. There were different TG curves for unprepared and calcined Magnetitum (Cishi) samples on heating. The former showed two weight-losing steps (at 367.9−422.1°C and 568.8−594.1°C), and the latter only one. These results might serve as a base for quality evaluation of Magnetitum (Cishi).