MOF-shielded and glucose-responsive ultrasmall silver nano-factory for highly-efficient anticancer and antibacterial therapy

Ag nanoparticles, a widely used antimicrobial agent, have been recently found to show unexpected anticancer effects. However, its medical applications in anticancer and antibacterial field are significantly hindered due to the size-dependent bioactivity. Considering the close relationship between tumor incidence and infection, herein, we reported the controlled encapsulation of large-size single Ag nanocube (50 nm) in zeolitic imidazolate frameworks (ZIF), accompanied with embedding of glucose oxidase (GOD). The obtained GOD/[email protected] could act as Ag nano-factory to generate ultrasmall Ag NPs (5 nm) as a response to tumor microenvironment. Specifically, GOD-induced generated H2O2 in glycolysis continuously decomposed AgNC into Ag+ and ultrasmall Ag NPs, where biocompatible ZIF-8 acted as the porous support for Ag+ and Ag NPs formation. Further, the GOD/[email protected] were coated with hyaluronic acid (HA), termed by GOD/[email protected], to allow the nanocomposites with good biocompatibility and target ability. GOD/[email protected] could completely suppress growth of two model bacteria strains at low concentration (E. coli. for 5 μg/mL, S. aureus for 10 μg/mL). More importantly, the high-performance anticancer activity of GOD/[email protected] and the underlying mechanism was also elaborated based on MCF-7 breast tumor model. We believe this study presents enticing possibilities to break through the size restriction of Ag NPs in biomedicine application.