Inorganic nanoparticles with unique physical properties have been explored as nanomedicines for brain tumor treatment. However, the clinical applications of the inorganic formulations are often hindered by the biological barriers and failure to be bioeliminated. The size of the nanoparticle is an essential design parameter which plays a significant role to affect the tumor targeting and biodistribution. Here, we report a feasible approach for the assembly of gold nanoparticles into ~80 nm nanospheres as a drug delivery platform for enhanced retention in brain tumors with the ability to be dynamically switched into the single formulation for excretion. These nanoassemblies can target epidermal growth factor receptors on cancer cells and are responsive to tumor microenvironmental characteristics, including high vascular permeability and acidic and redox conditions. Anticancer drug release was controlled by a pH-responsive mechanism. Intracellular L-glutathione (GSH) triggered the complete breakdown of nanoassemblies to single gold nanoparticles. Furthermore, in vivo studies have shown that nanospheres display enhanced tumor-targeting efficiency and therapeutic effects relative to single-nanoparticle formulations. Hence, gold nanoassemblies present an effective targeting strategy for brain tumor treatment.

中文翻译：

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金纳米粒子的自组装显示微环境介导的动态切换和增强的脑肿瘤靶向。

具有独特物理性质的无机纳米颗粒已经被研究作为用于脑肿瘤治疗的纳米药物。然而，无机制剂的临床应用常常受到生物屏障和不能被生物消除的阻碍。纳米颗粒的大小是必不可少的设计参数，在影响肿瘤靶向和生物分布方面起着重要作用。在这里，我们报告了一种可行的方法，可将金纳米颗粒组装成〜80 nm纳米球，作为药物递送平台以增强在脑肿瘤中的滞留性，并能够动态转换成单个制剂进行排泄。这些纳米组件可以靶向癌细胞上的表皮生长因子受体，并对肿瘤的微环境特征有反应，包括高血管通透性以及酸性和氧化还原条件。抗癌药物的释放是通过pH响应机制控制的。细胞内L-谷胱甘肽（GSH）触发了纳米组件向单个金纳米颗粒的完全分解。此外，体内研究表明，相对于单纳米颗粒制剂，纳米球显示出增强的肿瘤靶向效率和治疗效果。因此，金纳米组件为脑肿瘤治疗提供了一种有效的靶向策略。