Metal–Organic Framework (MOF) Hybrid as a Tandem Catalyst for Enhanced Therapy against Hypoxic Tumor Cells

Encapsulation of active biomolecules and/or nanoparticles in metal–organic frameworks (MOFs) remains a great challenge in biomedical applications. In this work, through a stepwise in situ growth method, a black phosphorus quantum dot (BQ) and catalase were precisely encapsulated into the inner and outer layers of MOFs, respectively. The integrated MOF system as a tandem catalyst could convert H 2 O 2 into O 2 in MOF‐stabilized catalase outer layer, and then O 2 was directly injected into MOF‐sensitized BQ inner, leading to high quantum yield of singlet oxygen. Upon internalization, the photodynamic therapy efficiency of the MOF system was 8.7‐fold greater than that without catalase, showing an enhanced therapeutic effect against hypoxic tumor cells. Furthermore, by coupling with photothermal therapy of BQs, photodynamic‐thermal synergistic therapy was realized both in vitro and in vivo.