150 research outputs found

    Iron-Chelated Polydopamine Decorated Doxorubicin-Loaded Nanodevices for Reactive Oxygen Species Enhanced Cancer Combination Therapy

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    Combination therapy which enhances efficacy and reduces toxicity, has been increasingly applied as a promising strategy for cancer therapy. Here, a reactive oxygen species (ROS) that enhanced combination chemotherapy nanodevices was fabricated based on the Fe-chelated polydopamine (PDA) nanoparticles (NPs). The structure was characterized by dynamic light scattering-autosizer, transmission electron microscopy, energy dispersive spectroscopy, and Fourier-transform infrared (FT-IR) spectrophotometer. The in vitro drug release profile triggered by low intracellular pH indicated that the system demonstrated controlled therapeutic activity. In vitro cell uptake studies showed that doxorubicin (DOX)-loaded Fe-PDA/ folic acid (FA)- polyethylene glycol (DOX@Fe-PDA/FA-PEG) had a strong uptake capacity and can be rapidly internalized by MCF-7 cells. The in vitro experiments demonstrated that DOX@Fe-PDA/FA-PEG triggered the intracellular ROS overproduction, thereby enhancing its therapeutic effect on breast cancer. In summary, this experiment demonstrated the novel DOX-loaded composite NPs used as a potential targeted nanocarrier for breast cancer treatment, which could be a promising therapeutic strategy against breast cancer

    The immunomodulatory peptide bursopentin (BP5) enhances proliferation and induces sIgM expression in DT40 cells

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    Background: In the recent past, many studies have been focused on extracts of BF and multiple biologically active factors and their effects on humoral immune system in chickens and birds. However, the mechanism of those immunomodulatory peptides on the B lineage cells proliferation and antibody production in chicken is fairly unknown. DT40 cell line, an avian leucosis virus-induced chicken pre-B cell line, expresses immunoglobulin M (IgM) isotype B cell reporter in the plasma membrane. There are many evidences suggesting that DT40 cells are best characterized as a bursal stem cell line. Because of the unique characteristics of DT40 cell line, it has been widely used to observe biological processes of pre-B lymphocyte cell within living cells. Methods: The chicken B cell line DT40 was cultured in Roswell Park Memorial Institute (RPMI) 1640 medium and cytotoxicity was studied. Also, effect of BP5 on cell proliferation and cell cycle distribution of DT40 cells was studied. Also, the effect of BP5 on sIgM mRNA expression was studied by using real-time PCR. Objectives: To investigat the effects of Bursopentin (Cys-Lys-Arg-Val-Tyr, BP5) on a chicken promyelocyte cell line DT40, assays of cell proliferation, cell cycle distribution, detection of surface immunoglobulin G (sIgM) mRNA expression and gene microarray analysis were performed. Results: The results showed that BP5 displayed concentration-dependent effects on the proliferation, cell cycle, and sIgM mRNA expression in DT40 cells. And the analysis of expression profiles identified a signature set of 3022 genes (1254 up regulated genes, 1762 down regulated genes), which clearly discriminated the BP5-treated DT40 cells from control with high certainty (P 640.02). The results of microarray analysis were confirmed by quantitative reverse transcription-polymerase chain reaction for 12 of the differentially expressed genes. Conclusion: Theses findings showed the immuno-activity effect of BP5 on B lymphocyte and indicated that BP5 treatment regulated eight signaling pathways, in which Toll-like signaling pathway was the most significant enrichment pathway

    Carotenoids Play a Positive Role in the Degradation of Heterocycles by Sphingobium yanoikuyae

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    BACKGROUND: Microbial oxidative degradation is a potential way of removing pollutants such as heterocycles from the environment. During this process, reactive oxygen species or other oxidants are inevitably produced, and may cause damage to DNA, proteins, and membranes, thereby decreasing the degradation rate. Carotenoids can serve as membrane-integrated antioxidants, protecting cells from oxidative stress. FINDINGS: Several genes involved in the carotenoid biosynthetic pathway were cloned and characterized from a carbazole-degrading bacterium Sphingobium yanoikuyae XLDN2-5. In addition, a yellow-pigmented carotenoid synthesized by strain XLDN2-5 was identified as zeaxanthin that was synthesized from β-carotene through β-cryptoxanthin. The amounts of zeaxanthin and hydrogen peroxide produced were significantly and simultaneously enhanced during the biodegradation of heterocycles (carbazole < carbazole + benzothiophene < carbazole + dibenzothiophene). These higher production levels were consistent with the transcriptional increase of the gene encoding phytoene desaturase, one of the key enzymes for carotenoid biosynthesis. CONCLUSIONS/SIGNIFICANCE: Sphingobium yanoikuyae XLDN2-5 can enhance the synthesis of zeaxanthin, one of the carotenoids, which may modulate membrane fluidity and defense against intracellular oxidative stress. To our knowledge, this is the first report on the positive role of carotenoids in the biodegradation of heterocycles, while elucidating the carotenoid biosynthetic pathway in the Sphingobium genus

    The 5th International Conference on Biomedical Engineering and Biotechnology (ICBEB 2016)

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    Catalysing sustainable fuel and chemical synthesis

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    Concerns over the economics of proven fossil fuel reserves, in concert with government and public acceptance of the anthropogenic origin of rising CO2 emissions and associated climate change from such combustible carbon, are driving academic and commercial research into new sustainable routes to fuel and chemicals. The quest for such sustainable resources to meet the demands of a rapidly rising global population represents one of this century’s grand challenges. Here, we discuss catalytic solutions to the clean synthesis of biodiesel, the most readily implemented and low cost, alternative source of transportation fuels, and oxygenated organic molecules for the manufacture of fine and speciality chemicals to meet future societal demands

    Thermal Performance Simulation of the Metal Foam Heat Sink

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    A study of the changes of Th17 cells and IL-23 in patients with Guillain-Barré syndrome

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    <p>Guillain-Barré syndrome (GBS) is an acute autoimmune-mediated inflammatory neuropathy. In this paper, the percentage of Th17 in peripheral blood lymphocyte and the level of IL-23 in serum and cerebrospinal fluid (CSF) of patients with GBS were detected. Twenty-five patients with GBS and 20 controls were analyzed. The percentage of Th17 cells in patients with GBS was (4.86 ± 0.60)%, which was higher than that in controls [(2.71 ± 0.54)%; <em>t</em> = 2.616, <em>P</em> = 0.012]. Serum IL-23 increased in patients with GBS [(111.80 ± 13.84) pg/ml vs (72.55 ± 8.19) pg/ml;<em> t</em> = 2.300, <em>P</em> = 0.026]. The level of IL-23 in serum and CSF from patients with GBS before therapy [(110.50 ± 15.66) and (102.30 ± 7.52) pg/ml] declined to normal after therapy [(74.13 ± 6.18) and (72.92 ± 12.09) pg/ml], and the difference was statistically significant (<em>t </em>= 2.557, <em>P</em> = 0.022; <em>t</em> = 1.422, <em>P</em> = 0.046). Th17 cells and IL-23 increased in patients with GBS, indicating that they may involve in the pathogenesis of GBS.</p><p> </p><p>doi: 10.3969/j.issn.1672-6731.2014.06.012</p
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