Oxygen Self‐Supplying Enzymatic Nanoplatform for Precise and Enhanced Photodynamic Therapy

Abstract

AbstractTraditional oxygen‐dependent photodynamic therapy (PDT) faces formidable challenges owing to abnormal angiogenesis and insufficient oxygen supply in solid tumors. Herein, a multifunctional nanoplatform (HRP‐DPBF‐Zn) consisting of photosensitizer zinc (II) phthalocyanine (ZnPc), singlet oxygen (1O2) probe 1,3‐diphenylisobenzofuran (DPBF), and hydrogen peroxide (H2O2) catalyst horseradish peroxidase (HRP) is developed. Such HRP‐DPBF‐Zn nanosystems are expected to possess catalase‐like capacity for catalyzing intracellular H2O2 to produce oxygen (O2). The enhanced O2 content further facilitates the production of cytotoxic 1O2 by ZnPc under laser irradiation. DPBF loading endows the nanoplatform with the high 1O2 sensitivity, which can promote precise PDT with fluorescent 1O2 feedback. HRP‐DPBF‐Zn exhibits excellent biocompatibility, efficient 1O2 generation, high 1O2 sensitivity, favorable H2O2‐to‐O2 decomposition, and superior fluorescence imaging properties. Both in vitro and in vivo experimental results confirm that such HRP‐DPBF‐Zn can accomplish highly specific and efficient PDT against hypoxic tumors, which shows great potential in tumor theranostics.