Engineering Zeolitic Imidazolate Framework-8 Nanoparticles for Smart Drug Delivery Systems

Zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs) are emerging metal-organic framework nanomaterials composed of 2-methylimidazole and zinc ions, which are widely used in biomedical fields due to their distinctive features such as high porosity, bioresponsive degradation, and superior biocompatibility. Especially, the advanced research of ZIF-8 NPs in smart drug delivery systems is providing unique insights into the rational design of versatile nanomedicines for the treatment and diagnosis of serious diseases. This article provides a comprehensive review and outlook on ZIF-8 NPs-based smart drug delivery systems (SDDSs) including the synthesis methods, drug loading strategies, surface modification, and stimuli-responsive release. In particular, we focus on the advantages of ZIF-8 NPs-based drug loading strategies between the metal coordination-based active loading and the physical packaging-based passive loading. Finally, the opportunities and challenges of ZIF-8 NPs as smart drug delivery carriers are discussed.