Metal−‐organic frameworks (MOFs), a new type of porous crystalline material, hold great potential in biomedical applications, such as drug delivery. However, the efficacy of drug delivery is limited by low drug loading. In this work, we synthesized hollow mesoporous silica (HMS)@MOF capsules that can be used as a pH‐responsive drug delivery system for the anticancer drug doxorubicin (DOX). DOX is loaded into the inner cavity of HMS. Zeolitic imidazolate framework‐8 (ZIF‐8) nanoparticles are then coated on the outer surface of the DOX‐loaded HMS. The obtained material is a capsule (denoted as DOX/HMS@ZIF), in which DOX is encapsulated. The DOX/HMS@ZIF can be used as an efficient pH‐responsive drug delivery system. DOX is not released under physiological conditions (pH 7.4), but is released at low pH (4–6) from DOX/HMS@ZIF. The DOX/HMS@ZIF capsule shows much higher cytotoxicity than free DOX and alters the delivery pathway for DOX in cancer cells, while the drug‐free HMS@ZIF shows excellent biocompatibility. This opens new opportunities to construct a safe and efficient delivery system for targeted molecules using pH‐responsive release for a wide range of applications.

中文翻译：

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空心介孔二氧化硅@金属-有机骨架及其对pH响应药物的递送应用

金属有机框架（MOF）是一种新型的多孔晶体材料，在生物医学应用（如药物输送）中具有巨大的潜力。然而，药物递送的功效受到低药物载量的限制。在这项工作中，我们合成了空心中孔二氧化硅（HMS）@MOF胶囊，可用作抗癌药物阿霉素（DOX）的pH响应药物递送系统。将DOX加载到HMS的内部空腔中。然后将沸石咪唑盐骨架8（ZIF-8）纳米颗粒涂在装有DOX的HMS的外表面上。获得的材料是胶囊（表示为DOX / HMS @ ZIF），其中封装了DOX。DOX / HMS @ ZIF可以用作有效的pH响应药物递送系统。DOX不会在生理条件下（pH 7.4）释放，而是在低pH值（4–6）下从DOX / HMS @ ZIF释放。DOX / HMS @ ZIF胶囊显示出比游离DOX高得多的细胞毒性，并改变了DOX在癌细胞中的传递途径，而无药物的HMS @ ZIF显示出优异的生物相容性。这为利用pH响应释放为广泛的应用构建针对目标分子的安全有效的传递系统提供了新的机会。