ABSTRACT
Fe3O4@SiO2@Ag ternary hybrid nanoparticles were synthesized via a facile seed-mediated growth route. X-ray diffraction, transmission electron microscopy and vibrating sample magnetometer measurements were used to characterize the as-prepared product. The results indicated that the nanoparticles exhibited excellent magnetic properties and an extremely dense structure with Ag layer thicknesses of 30, 40, and 50 nm. Furthermore, the microwave shielding effectiveness exceeded 20 dB over almost the entire frequency range (2-18 GHz), and the effectiveness obviously improved as the thickness of the Ag layer increased. In addition, the IR extinction coefficient of the nanoparticles was calculated by a finite-difference time-domain method, which showed that the nanoparticles can inherit the extinction performance of pure silver when the Ag shell thickness was 30 nm. Specifically, after assembling into chains, the peak position of the IR extinction curves displayed a significant redshift and an intensity increase as the number of nanoparticles increased in the chain, which dramatically promoted the IR extinction capability. As a result, the Fe3O4@SiO2@Ag nanoparticles are expected to be used as a new multispectral interference material.
ABSTRACT
Oxymatrine has been shown to exert an antitumor effect on several types of cancer cells. However, the role of oxymatrine in bladder cancer has not yet been evaluated. The present study was designed to investigate the potential anti-proliferative effect of oxymatrine on bladder cancer T24 cells and the possible mechanisms involved. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to determine cell growth, and the cell morphology was examined using hematoxylin and eosin staining, wrights' staining and electron microscopy. The caspase-3 and survivin mRNA and protein levels were assessed using reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. The expression of tumor protein p53 (p53), Bcl-2-associated X protein (Bax) and B-cell lymphoma 2 (Bcl-2) were analyzed using immunohistochemistry. Oxymatrine inhibited the proliferation of the T24 cells in a dose- and time-dependent manner. Oxymatrine also induced apoptosis and cell cycle arrest in the cells, in association with the upregulation of caspase-3 and Bax, and the downregulation of survivin, Bcl-2 and p53 expression. Overall, oxymatrine inhibits the proliferation of human bladder cancer cells by inducing apoptosis and cell cycle arrest via mechanisms that involve p53-Bax signaling and the downregulation of survivin expression.
