A Self-Immobilizing Photosensitizer with Long-Term Retention for Hypoxia Imaging and Enhanced Photodynamic Therapy

The precise theranostic strategy of fluorescence imaging-guided photodynamic therapy (PDT) can effectively mitigate the adverse effect of photosensitizers in normal cells and tissues. However, low tumor enrichment and high diffusivity of photosensitizers significantly compromise the imaging accuracy and PDT effect. In this study, we have developed a nitroreductase (NTR)-activated and self-immobilizing photosensitizer CyNT-F, which showed enhanced enrichment in tumor tissues and facilitated precise and sustained imaging as well as PDT for hypoxia tumors. mPEG-