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AIM:To study the toxicity of PM2.5 in the endothelial cells by investigating the induction of reactive oxygen species (ROS) and apoptosis in EA.hy926 cells exposed to PM2.5.METHODS: The endothelial cell line EA. hy926 was cultured in vitro and exposed to PM2.5 at different concentrations for 24 h.The cell viability was measured by CCK-8 assay and the generation of intracellular ROS was stained with DCFH-DA.The cell apoptosis was analyzed by flow cy-tometry with Annexin V-FITC/PI staining, and the protein levels of cytochrome C , caspase 9 and caspase 3 was detected by Western blot.RESULTS:After the treatment with PM2.5, the viability of the EA.hy926 cells was decreased markedly and the production of ROS was increased significantly .PM2.5 exposure upregulated the expression of cytoplasm cytochrome C and activated caspase-9 and caspase-3, resulting in the increase of the cell apoptosis significantly .The ROS generation was direct-ly involved in PM2.5-mediated endothelial cell apoptosis as N-acetyl-L-cysteine pretreatment abolished both ROS production and cell apoptosis induced by PM 2.5.CONCLUSION:PM2.5 induces oxidative stress and apoptosis in the vascular endo-thelial cells, which may be one of the mechanisms that PM2.5 influences the function of cardiovascular system .
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Objective To prepare polypeptide nerve growth factor (NGF) thermosentitive gel and observe drug release in vitro,in order to provide scientific information for biopharmaceuticals delivery system design aiming to treat the inner disease.Methods The thermosensitive in situ gel was prepared with NGF as main component and Pluronic F127 as the gel matrixes.The effect of concentration of gel matrix PF127 on lower critical solution temperature(LCST) were investigated.In vitro release kinetic studies were performed using membraneless dissolution method and reversed-phase high performance liquid chromatography (HPLC) method was adopted to determine NGF content in the dissolution medium.Results The average LCST of NGF-loaded gel prepared by different concentration of PF127 was 28.48-36.26℃ and the gels had good stability.The in vitro release kinetics was well characterized by sustained release and can be fitted by zero order kinetics.The in vitro accumulated release ratio of NGF in the thermosensitive gel reached to above 95％.hβ-NGF loaded in higher PF127 gel resulted in a more sustained release of hβ-NGF from the thermosensitive gel.Conclusion Well-prepared NGF thermosensitive gel is a promising inner ear-oriented drug delivery system for treating deafness and deserves to further development.
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0.05) and the histopathological results of the test group did not show any inflammatory reaction in incisions of liver and kidney tissues.Muscular tissues allowed a little inflammatory cells infiltrate at two days,after four days,there was not inflammation or fibrous tissue envelope.CONCLUSION:The prepared PHS granules have good biocompatibility without any acute or chronic toxicity,reject reaction,immunological reaction and anaphylactic response in animals.