ABSTRACT
Atomically dispersed Pt catalysts are synthesized on TiO2 with high activity and strong high temperature resistance by loading Pt in the process of converting the NH4TiOF3 precursor to TiO2 by a topotactic transformation process. The atomically dispersed Pt catalyst displayed high catalytic activity for the low temperature CO oxidation reaction.
ABSTRACT
Biological applications of nanosheets are rapidly increasing currently, which introduces new possibilities to improve the efficacy of cancer chemotherapy and radiotherapy. Herein, we designed and synthesized a novel nano-drug system, doxorubicin (DOX) loaded titanium peroxide (TiO x ) nanosheets, toward the synergistic treatment of lung cancer. The precursor of TiO2 nanosheets with high specific surface area was synthesized by a modified hydrothermal process using the polymer P123 as a soft template to control the shape. TiO x nanosheets were obtained by oxidizing TiO2 nanosheets with H2O2. The anti-cancer drug DOX was effectively loaded on the surface of TiO x nanosheets. Generation of reactive oxygen species, including H2O2, ·OH and ·O2 -, was promoted from TiO x nanosheets under X-ray irradiation, which is effective for cancer radiotherapy and drug release in cancer cells. In this way, chemotherapy and radiotherapy were combined effectively for the synergistic therapy of cancers. Our results reinforce the DOX loaded TiO x nanosheets as a pH sensitive and X-ray controlled dual-stimuli-responsive drug release system. The cytotoxicity, cellular uptake, and intracellular location of the formulations were evaluated in the A549 human non-small cell lung cancer cell line. Our results showed that TiO x /DOX complexes exhibited a greater cytotoxicity toward A549 cells than free DOX. This work demonstrates that the therapeutic efficacy of DOX-loaded TiO x nanosheets is strongly dependent on their loading mode and the chemotherapeutic and radiotherapy effect is improved under X-ray illumination, which provides a significant breakthrough for future applications of TiO x as a light activated drug carrier in cancer chemotherapy and radiotherapy.
ABSTRACT
A high performance liquid chromatographic method was established for the determination of acteoside in Mitonghua particles and Brandisia hancei. The results showed that acteoside can be extracted more efficiently with butanol than with water. Therefore, both Mitonghua particles and Brandisia hancei were extracted with butanol. The extracts were analysed on an RP-18 column using a mixture of CH3OH-0.5% aqueous HAc (42:58, v/v) as the mobile phase with UV detection at 334 nm. A good linear response was observed within the range of 0.029-2.038 microg of analytes (r = 0.9998). The recoveries were 90.2%-93.8% and the relative standard deviation was 0.34% (n = 5). This rapid, simple, accurate, and reproducible method is proposed for the quality control of Mitonghua particles.
