Tailored core‒shell dual metal–organic frameworks as a versatile nanomotor for effective synergistic antitumor therapy

Malignant tumor has become an urgent threat to global public healthcare. Because of the heterogeneity of tumor, single therapy presents great limitations while synergistic therapy is arousing much attention, which shows desperate need of intelligent carrier for co-delivery. A core‒shell dual metal–organic frameworks (MOFs) system was delicately designed in this study, which not only possessed the unique properties of both materials, but also provided two individual specific functional zones for co-drug delivery. Photosensitizer indocyanine green (ICG) and chemotherapeutic agent doxorubicin (DOX) were stepwisely encapsulated into the nanopores of MIL-88 core and ZIF-8 shell to construct a synergistic photothermal/photodynamic/chemotherapy nanoplatform. Except for efficient drug delivery, the MIL-88 could be functioned as a nanomotor to convert the excessive hydrogen peroxide at tumor microenvironment into adequate oxygen for photodynamic therapy. The DOX release from MIL-88-ICG@ZIF-8-DOX nanoparticles was triggered at tumor acidic microenvironment and further accelerated by near-infrared (NIR) light irradiation. The in vivo antitumor study showed superior synergistic antitumor effect by concentrating the nanoparticles into dissolving microneedles as compared to intravenous and intratumoral injection of nanoparticles, with a significantly higher inhibition rate. It is anticipated that the multi-model synergistic system based on dual-MOFs was promising for further biomedical application.