Multifunctional core-shell nanocarriers based on zinc oxide (ZnO)-gated magnetic mesoporous silica nanoparticles (MMSN) were prepared for cancer treatment through magnetic targeting and pH-triggered controlled drug release. Under an external magnetic field, the MMSN could actively deliver chemotherapeutic agent, daunomycin (DNM), to the targeted sites. At neutral aqueous, the functionalized MMSN could stably accommodate the DNM molecules since the mesopores were capped by the ZnO gatekeepers. In contrast, at the acid intercellular environment, the gatekeepers would be removed to control the release of drugs due to the dissolution of ZnO. Meanwhile, ZnO quantum dots not only rapidly dissolve in an acidic condition of cancer cells but also enhance the anti-cancer effect of Zn2+. An in vitro controlled release proliferation indicated that the acid sensitive ZnO gatekeepers showed well response by the 'on-off' switch of the pores. Cellular experiments against cervical cancer cell (HeLa cells) further showed that functionalized MMSN significantly suppressed cancer cells growth through synergistic effects between the chemotherapy and Zn2+ ions with monitoring the treatment process. These results suggested that the ZnO-gated MMSN platform is a promising approach to serve as a pH-sensitive system for chemotherapies delivery and Zn2+ controlled release for further application in the treatment of various cancers by synergistic effects.

中文翻译：

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氧化锌封端的 Fe3O4@mSiO2 核壳纳米载体作为化学/离子协同治疗的靶向和响应药物递送系统。

基于氧化锌 (ZnO) 门控磁性介孔二氧化硅纳米粒子 (MMSN) 的多功能核壳纳米载体通过磁性靶向和 pH 触发控制药物释放制备用于癌症治疗。在外部磁场下，MMSN 可以主动将化疗药物道诺霉素 (DNM) 递送到目标部位。在中性水溶液中，功能化的 MMSN 可以稳定地容纳 DNM 分子，因为中孔被 ZnO 看门人覆盖。相反，在酸性细胞间环境中，由于ZnO的溶解，守门者将被去除以控制药物的释放。同时，ZnO量子点不仅能在癌细胞的酸性条件下迅速溶解，还能增强Zn2+的抗癌作用。体外控释增殖表明，酸敏感的 ZnO 看门人通过孔的“开关”开关表现出良好的响应。针对宫颈癌细胞（HeLa 细胞）的细胞实验进一步表明，功能化 MMSN 通过化疗和 Zn2+ 离子之间的协同作用并监测治疗过程，显着抑制癌细胞生长。这些结果表明，ZnO 门控 MMSN 平台是一种很有前景的方法，可用作化疗递送和 Zn2+ 控制释放的 pH 敏感系统，通过协同作用进一步应用于各种癌症的治疗。