Manganese Dioxide Nanoplatform with a Hollow Rhombic Dodecahedron Morphology for Drug Delivery.

Manganese dioxide (MnO 2 ) is considered as a promising drug carrier material suitable for the tumor microenvironment while lacking conducive structures for drug loading. Herein, we construct a MnO 2 nanoplatform with a hollow rhombic dodecahedral morphology for drug delivery. In this work, we obtained zeolitic imidazolate framework nanoparticles (ZIF-90 NPs) via a coordination reaction. Furthermore, the drug-loading nanoparticles (ZIF-90/DOX NPs) were obtained by Schiff's base reaction and then selected as a sacrificial template to obtain the hollow nanoplatforms (ZIF-90@MnO 2 NPs). Moreover, the photothermal effect and multiresponsive drug release behaviors were revealed by loading the photothermal agent IR-820 and the anticancer drug doxorubicin hydrochloride (DOX). Our study demonstrates that the ZIF-90@MnO 2 NPs loaded with photosensitizers exhibited excellent photothermal conversion performance. Benefiting from the hollow structure and redox activity, remarkable drug loading and release performances of ZIF-90@MnO 2 NPs were achieved. It is shown that ZIF-90@MnO 2 NPs achieved a satisfactory drug-loading efficiency (up to ca. 69.7%) for DOX. More promisingly, the ZIF-90@MnO 2 NPs exhibited significant glutathione (GSH)/pH-responsive drug release and degradation performances. Overall, this work highlights the potential of controlled drug release of nanocarriers and offers unique insights into the design of nanocarriers with hollow structures.