Recently, the development of drug delivery which delivers controlled drug release at the tumor sites emerged as an attractive option for enhancing anticancer therapeutics. Next-generation nanotherapeutics must not contain only the nanoscale but should find their way to the solid tumor via active or passive targeting. Surface modification by pegylated lipids is one of the approaches used to made liposomes long-circulating and passively target the tumor. Pegylation of liposomes help them to alter the pharmacokinetics of drug molecule in vivo. The successful journey of such a complex drug delivery system from bench to clinic requires in-depth understanding and characterization. In this research, we fabricated and characterized sterically stabilized liposomes of topotecan which meets the clinical need. Liposomes have been prepared using ethanol injection-solvent evaporation method followed by extrusion for size reduction. Outer medium was replaced with an isotonic sucrose solution using dialysis followed by drug loading. We characterized liposomes’ membrane phase and dynamics, drug and lipid quantification, size distribution, state of encapsulated drug, internal volume and internal pH of liposomes, presence, and thickness of grafted PEG on the liposomes surface, and in vitro leakage test. All these studied parameters directly or indirectly provide information regarding the pharmacokinetic behavior of the formulation and the tumor-targeting property of the drugs in vivo. We encapsulated the topotecan in nanoliposomes with pegylation on the surface resulting in long-circulating stealth liposomes. Nanoliposomes remotely loaded with topotecan by transmembrane gradient method. Our in vitro characterization of topotecan liposomes provides an explanation for the good therapeutic efficacy of tumor cells.

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拓扑替康的空间稳定脂质体的制备和表征

近来，在肿瘤部位递送受控药物释放的药物递送的发展出现为增强抗癌治疗剂的有吸引力的选择。下一代纳米疗法必须不仅包含纳米级，而且应通过主动或被动靶向找到进入实体瘤的途径。聚乙二醇化脂质的表面修饰是使脂质体长循环并被动靶向肿瘤的方法之一。脂质体的聚乙二醇化帮助他们改变体内药物分子的药代动力学。如此复杂的药物输送系统从工作台到诊所的成功历程，需要深入的了解和表征。在这项研究中，我们制造并表征了符合临床需要的拓扑替康的空间稳定脂质体。已经使用乙醇注入-溶剂蒸发方法制备脂质体，然后挤出以减小尺寸。通过渗析，然后加药，用等渗蔗糖溶液代替外层介质。我们表征了脂质体的膜相和动力学，药物和脂质定量，大小分布，包封的药物状态，脂质体的内部体积和内部pH，脂质体表面上已存在的PEG的厚度和厚度以及体外渗漏测试。所有这些研究的参数直接或间接地提供了有关制剂的药代动力学行为和体内药物靶向肿瘤的信息。我们将托泊替康包裹在纳米脂质体中，并在其表面进行聚乙二醇化，从而形成了长循环的隐形脂质体。通过跨膜梯度法远程装载拓扑替康的纳米脂质体。我们对拓扑替康脂质体的体外表征为肿瘤细胞的良好治疗效果提供了解释。