Radiosensitivity enhancement effect of FePd@CNTs nanocomposites on MCF-7 cells / 中华放射肿瘤学杂志

Objective:To evaluate the radiosensitivity enhancement effect of FePd@CNTs nanocomposites on human breast cancer MCF-7 cells.Methods:FePd@CNTs nanocomposites were synthesized by chemical reduction method. Transmission electron microscope and energy dispersive spectrometer were utilized to characterize the surface morphology and chemical composition of FePd@CNTs nanocomposites. The compatibility of FePd@CNTs nanocomposites with human normal breast epithelial MCF-10A cells was determined by CCK-8 assay. The radiosensitivity enhancement effect of FePd@CNTs nanocomposites on MCF-7 cells was assessed by CCK-8 assay, flow cytometry and clony formation assay.Results:FePd nanospheres were successfully modified on the surface of CNTs by chemical reduction method. FePd@CNTs nanocomposites showed a low toxicity to MCF-10A cells (IC 50=738.3 μg/m), and effectively enhanced the effect of X-ray radiation on MCF-7 cells (sensibilization ratio=1.22). Conclusion:FePd@CNTs nanocomposites exhibit a promising potential for treating breast cancer and enhancing radiosensitivity effect.

Pulmonary toxicity of single-wall carbon nanotubes and its oxidative stress mechanism / 第二军医大学学报

Objective To systematically study the pulmonary toxicity of single-wall carbon nanotubes (SWCNTs) and to explore the related cytotoxicity mechanism, so as to provide a theoretical basis for the safe productionandapplication of SWCNTs. Methods A549 cells were cultured in the media containing 0, 25, 50, 100, 150, and 200 μg/mL SWCNTs for 24 h, and then the cell viability and degree of cell membrane damage were assessed by CCK-8 and lactate dehydrogenase (LDH) release assay kit, respectively; the ultrastructural alteration of A549 cells was detected by transmission electron microscope (TEM). The oxidative stress response was evaluated by assessing reactive oxygen species (ROS), glutathione (GSH) and superoxide dismutase (SOD). The rats were exposed to SWCNTs by intratracheal inhalation, and then the animals were sacrificed 3 days later and the pathological sections of lung tissue were examined. Results SWCNTs showed considerable toxicity to A549 cells, decreasing cell viability, causing severe damage of cell membrane and ultrastructure, increasing the intracellular ROS level, and decreasing GSH content and SOD activity. It was found that oxidative stress is the main mechanism of SWCNTs toxicity on A549 cells. In vivo toxicity results showed that SWCNTs accumulated in the lung tissue # causing alveolar wall edema. Conclusion In vitro and in vivo toxicity results have found that SWCNTs possess a significant pulmonary toxicity # with its main toxicity mechanismbeing oxidative stress.

Determination of Pb(Ⅱ) Based on Dehydroabietylamine Schiff Base-Multi-walled Carbon Nano-tubes Modified Glassy Carbon Electrode / 分析化学

A novel electrochemical method based on dehydroabietylamine schiff base( DBS) and multi-walled carbon nano-tubes( MWCNTs) composite modified glassy carbon electrode was presented for determination of Pb2+. The electrochemical behaviors of Pb2+on the modifled electrode were investigated by cyclic voltammetry ( CV) and differential pulse anodic stripping voltammetry ( DPASV ) . The results showed that under the optimized conditions including 0 . 2 mol/L NaAc-HAc used as supporting buffer ( pH 5 . 5 ) , -1 . 1 V of accumulating potential, 250 s of accumulating time, the oxidation peak current was proportional to Pb2+concentration in the range between 1 × 10-8 mol/L and 1 × 10-6 mol/L with the linear regression equation as I(μA)= 6. 6173c(μmol/L)+0. 2597(R=0. 9971) and the detection limit as 5. 0×10-9 mol/L (S/N=3). The proposed sensor was successfully employed to determine Pb2+ in real samples with satisfactory results. In addition, this method showed the advantages of simple operation, short assay time, good accuracy, satisfactory efficiency and good selectivity for determination of low concentration lead in water samples.