Tailored synthesis of hollow MOF/polydopamine Janus nanoparticles for synergistic multi-drug chemo-photothermal therapy

Elaborate design of multifunctional Janus nanoparticles (JNPs) with asymmetric compositions and independent functions has drawn extensive attention in biological fields. Here, a mild synthesis strategy is first explored for the preparation of spherical zeolitic imidazolate framework-8/polydopamine JNPs with hollow structure (H-ZIF-8/PDA JNPs). The resultant H-ZIF-8/PDA JNPs are further selectively functionalized on PDA sides with heptakis-(6-mercapto-6-deoxy)-β-cyclodextrin (CDs) to gain the capability of loading hydrophobic drug (H-ZIF-8/PDA-CD JNPs). Meanwhile, the ZIF-8 domains with hollow cavities can serve as reservoirs for loading hydrophilic drug molecules. Moreover, the pH-sensitive ZIF-8 and the strong near-infrared (NIR) absorption of PDA make the H-ZIF-8/PDA JNPs possess the conversion capacity from laser energy to heat and pH/NIR dual-responsive drug release behaviors. Besides, the Cell Counting Kit-8 (CCK-8), hemolysis and histological assays manifest the excellent biocompatibility of H-ZIF-8/PDA-CD JNPs. The therapeutic results in vitro and in vivo both reveal that the hydrophobic/hydrophilic drugs co-loaded H-ZIF-8/PDA-CD JNPs irradiated by 808 nm laser groups show the best therapeutic efficiency. Taken together, the H-ZIF-8/PDA-CD JNPs are capable of serving as promising platform for cancer treatment through collaborative photothermal and dual-drug chemical therapy.