Organic Nanoparticles with Persistent Luminescence for In Vivo Afterglow Imaging‐Guided Photodynamic Therapy

Optical imaging-guided photodynamic therapy (PDT), with precise localization and non-invasive treatment of tumors, is an emerging technique with great potential for cancer therapy. However, impaired by tissue auto-fluorescence that causes low signal-to-background ratio (SBR), most fluorescence imaging systems show poor sensitivity to tumors in vivo . In this study, we synthesized organic nanoparticles (ONPs) with persistent luminescence and good biocompatibility for afterglow imaging-guided PDT. The ONPs displayed near-infrared light emission with half-life time at minute level, which offered high SBR and good tissue penetration for in vivo afterglow tumor imaging. Taking advantage of their abundant singlet oxygen generation by NIR laser irradiation guided to the tumor sites, the ONPs also enabled imaging-guided PDT for efficient suppression of tumor growth in mice with minimal damage to major organs.