Mg-5Zn-0.3Ca/nHA biocomposites were prepared from pure Mg,Zn,Ca and nano-hydroxyapatite(nHA)powders by powder metallurgy method.The effect of various mass fractions of nHA(1%,2.5%,5%)as reinforcement on the corrosion ...Mg-5Zn-0.3Ca/nHA biocomposites were prepared from pure Mg,Zn,Ca and nano-hydroxyapatite(nHA)powders by powder metallurgy method.The effect of various mass fractions of nHA(1%,2.5%,5%)as reinforcement on the corrosion properties of Mg-5Zn-0.3Ca alloy was investigated.The corrosion resistance of biocomposite samples was investigated by immersion tests and electrochemical techniques in SBF solution.The results showed that the corrosion resistance of Mg alloy was improved by adding 1%and 2.5%nHA.Bioactive nHA motivated the formation of stable phosphate and carbonate layers on surface and improved corrosion resistance of nanocomposites.However,addition of large contents of nHA in Mg alloy as reinforcement increased the density of this precipitated layer,so gases produced from localized corrosion were accumulated underneath this layer and decreased its adhesiveness and lowered its corrosion resistance.Indirect cytotoxicity evaluation for Mg alloy and its nanocomposites also showed that their extraction was not toxic and nanocomposite with 1%nHA indicated almost similar behavior as negative control.展开更多
In this In vitro study, T cell responses induced by breast tumor cell lysate pulsed monocyte-derived DCs were analyzed in terms of proliferation, specific cytotoxicity and cytokine-release in order to use in immunothe...In this In vitro study, T cell responses induced by breast tumor cell lysate pulsed monocyte-derived DCs were analyzed in terms of proliferation, specific cytotoxicity and cytokine-release in order to use in immunotherapeutic settings. Nylon wool enriched T lymphocytes from 5 patients with breast cancer stimulated In vitro with tumor cell lysate pulsed monocyte-derived DCs and their proliferation response were analyzed by [3H] thymidine uptake test. Specific cytotoxic activity of tumor antigen primed T cells after three rounds weekly stimulation was evaluated by flow cytometry, and interferon-γ (IFN-γ) and interleukin-4 (IL-4) cytokines release assay was carried out 24 hours after last stimulation in the supernatant of primed T cells using commercially available ELI-SA kits. T cell proliferation assay revealed that tumor cell lysate pulsed DCs could stimulate autologous T cell proliferation response with stimulation indices 4.9 - 30. T cell mediated cytotoxicity assay demonstrated that tumor antigen primed T cells could significantly kill autologous tumor cells more than normal cells (P γ and IL-4 in response to restimulation by antigen pulsed DCs which were dominated by IFN-γ production in 2 and IL-4 production in 3 out of 5 patients. Our result suggested that breast tumor antigen pulsed DCs could elicit effective specific antitumor T cell responses In vitro, therefore, tumor antigen pulsed DC vaccination may be considered as a novel strategy for immunotherapy of patients with breast cancer refractory to standard modalities.展开更多
文摘Mg-5Zn-0.3Ca/nHA biocomposites were prepared from pure Mg,Zn,Ca and nano-hydroxyapatite(nHA)powders by powder metallurgy method.The effect of various mass fractions of nHA(1%,2.5%,5%)as reinforcement on the corrosion properties of Mg-5Zn-0.3Ca alloy was investigated.The corrosion resistance of biocomposite samples was investigated by immersion tests and electrochemical techniques in SBF solution.The results showed that the corrosion resistance of Mg alloy was improved by adding 1%and 2.5%nHA.Bioactive nHA motivated the formation of stable phosphate and carbonate layers on surface and improved corrosion resistance of nanocomposites.However,addition of large contents of nHA in Mg alloy as reinforcement increased the density of this precipitated layer,so gases produced from localized corrosion were accumulated underneath this layer and decreased its adhesiveness and lowered its corrosion resistance.Indirect cytotoxicity evaluation for Mg alloy and its nanocomposites also showed that their extraction was not toxic and nanocomposite with 1%nHA indicated almost similar behavior as negative control.
文摘In this In vitro study, T cell responses induced by breast tumor cell lysate pulsed monocyte-derived DCs were analyzed in terms of proliferation, specific cytotoxicity and cytokine-release in order to use in immunotherapeutic settings. Nylon wool enriched T lymphocytes from 5 patients with breast cancer stimulated In vitro with tumor cell lysate pulsed monocyte-derived DCs and their proliferation response were analyzed by [3H] thymidine uptake test. Specific cytotoxic activity of tumor antigen primed T cells after three rounds weekly stimulation was evaluated by flow cytometry, and interferon-γ (IFN-γ) and interleukin-4 (IL-4) cytokines release assay was carried out 24 hours after last stimulation in the supernatant of primed T cells using commercially available ELI-SA kits. T cell proliferation assay revealed that tumor cell lysate pulsed DCs could stimulate autologous T cell proliferation response with stimulation indices 4.9 - 30. T cell mediated cytotoxicity assay demonstrated that tumor antigen primed T cells could significantly kill autologous tumor cells more than normal cells (P γ and IL-4 in response to restimulation by antigen pulsed DCs which were dominated by IFN-γ production in 2 and IL-4 production in 3 out of 5 patients. Our result suggested that breast tumor antigen pulsed DCs could elicit effective specific antitumor T cell responses In vitro, therefore, tumor antigen pulsed DC vaccination may be considered as a novel strategy for immunotherapy of patients with breast cancer refractory to standard modalities.
