【摘要】 目的:构建具有Fe₃O₄内核的磁性阳离子脂质体Fe₃O₄-CLs,考察其对内毒素分子（脂多糖LPS）的体外吸附作用,验证其对LPS诱导细胞损伤的保护作用以及内毒素血症小鼠的治疗效果。方法:采用水热法制备Fe₃O₄纳米粒子,通过薄膜分散法制备阳离子脂质体,并在水化过程中包裹Fe₃O₄纳米粒子,最终采用机械挤出法制备Fe₃O₄-CLs纳米载体,并对其形态、粒径及表面性质进行表征;采用鲎试剂法检测Fe₃O₄-CLs对LPS的体外吸附作用,然后探究Fe₃O₄-CLs对LPS诱导的细胞凋亡或细胞内活性氧（ROS）升高的抑制作用,最终构建内毒素血症小鼠模型,研究Fe₃O₄-CLs对内毒素处理的小鼠的体内治疗效果。结果:所构建的Fe₃O₄-CLs纳米载体大小均一,呈核壳型结构,粒径为150 nm。体外吸附实验表明Fe₃O₄-CLs纳米粒子对LPS的吸附率达到63%,能明显降低LPS诱导的细胞死亡率,下调细胞内ROS水平;小鼠实验结果显示Fe₃O₄-CLs能显著降低内毒素血症小鼠血清炎症因子白介素6（IL-6）和肿瘤坏死因子α（TNF-α）水平,抑制肝、肺组织损伤,可明显抑制LPS所致体温持续下降,最终降低内毒素血症小鼠死亡率,其存活率为75%。结论:以上结果表明,Fe₃O₄-CLs可吸附清除体内外LPS,对内毒素血症小鼠有明显的治疗效果,为体内毒素的直接清除和进一步载药治疗的联合应用做出了初步探索。更多还原

【Abstract】 Objective: To study the in vitro adsorption of endotoxin molecules（ lipopolysaccharide,LPS）by constructing magnetic cationic liposomes which possess Fe₃O₄ as the core（ Fe₃O₄-CLs）,and to verify its protective effect on LPS-induced cell injury and the therapeutic effect of endotoxemia in mice. Methods: Fe₃O₄ nanoparticles were synthesized using solvothermal method. Cationic liposomes were prepared by thin-film dispersion method,and Fe₃O₄ nanoparticles were wrapped in hydration process to form the final Fe₃O₄-CLs by mechanical extrusion. The morphology,particle size and surface properties of synthesized nanoparticles were characterized. The in vitro adsorption of LPS by Fe₃O₄-CLs was detected by limulus test and then to investigate the inhibition effect of Fe₃O₄-CLs on cell apoptosis and the rise of intracellular reactive oxygen species（ ROS） induced by LPS. Finally,a mouse model of endotoxemia was established to study the therapeutic effect of Fe₃O₄-CLs on LPS-treated mice in vivo.Results: The constructed Fe₃O₄-CLs nanoparticles were uniform in size of 150 nm,with a core-shell structure. Invitro neutralization experiments showed that the adsorption efficiency of Fe₃O₄-CLs nanoparticles to LPS reached to63%,which could significantly reduce the cell mortality and down-regulate the intracellular ROS level of cells induced by LPS. The results of mouse experiments showed that Fe₃O₄-CLs can significantly reduce the levels of serum inflammatory cytokines such as interleukin 6（ IL-6） and tumor necrosis factor α（ TNF-α） in endotoxemia mice,and inhibited liver and lung injury,and significantly inhibited the continuous decrease of body temperature induced by LPS. Ultimately reflected the mortality in mice with endotoxemia,with a survival rate of 75%. Conclusion:The above results indicated that Fe₃O₄-CLs could adsorb and remove LPS in vivo and in vitro,and had an obvious therapeutic effect on endotoxemia mice,which provided a preliminary exploration for the direct neutralization of toxins in vivo and the combined application of drug loading therapy.更多还原