In Vivo Monitoring Therapeutic Response by Self-Reporting Upconverting Covalent Organic Framework Nanoplatform

Real-time and in situ monitoring reactive oxygen species (ROS) generation is critical to minimize the nonspecific damages derived from the required high dose of ROS during photodynamic therapy (PDT) process. However, phototherapeutic agents that can generate ROS-related imaging signals during PDT are rare, which hampers the facile predication of therapeutic outcome ahead. Herein, we develop upconverting covalent organic framework (COF) nanoplatform via core-mediated strategy and further functionalized it with a singlet oxygen reporter for efficient near-infrared activated and in situ self-reporting PDT. In this work, the photodynamic efficacy of COFs is greatly improved (12.5 times of irregular COFs) via tailoring size. Furthermore, this nanoplatform is able to not only produce singlet oxygen for PDT, but also emit singlet oxygen-correlated luminescence, which fulfills the real-time and in situ monitoring therapeutic process for cancer cells or solid tumor in vivo via near-infrared luminescence imaging. Thus, our core-mediated synthetic and size-tailored strategy endow upconverting COF nanoplatform promising for high-efficacy, deep-tissue and precise photodynamic treatment.