Cell Membrane-Coated Porphyrin Metal-Organic Frameworks for Cancer Cell Targeting and O2-Evolving Photodynamic Therapy.

Photodynamic therapy (PDT) has attracted great attention as an alternative tumor treatment method. Unfortunately, it suffers from some limitations like poor targeting capability and insufficient therapeutic efficiency caused by tumor hypoxia. In this work, we introduce a novel O2-evolving PDT nanoparticle for homologous cancer cell targeting as well as dual-mode imaging [i.e., magnetic resonance imaging (MRI) and fluorescence imaging]. Specifically, the nanostructure consists of a MnO2 nanosheet-coated metal-organic framework core and cancer cell membrane shell (defined as CM-MMNPs). The MnO2 layer displays H+ and H2O2 responsiveness, which can produce O2 to enhance O2-mediated singlet oxygen (1O2) generation for PDT. Moreover, the resulted Mn2+ can also be used as an optimal MRI contrast agent. The introduction of cell membrane and membrane proteins endow the CM-MMNPs with good stability and integrity in the process of cellular endocytosis, as well as strong homologous cell-targeting ability. This multifunctional nanoparticle has the potential to overcome the hypoxia of cancer cells in PDT, and provides a new paradigm for tumor targeting, detection, and therapy, which is promising for biomedical applications in the future.