Recent advances in nitroreductase-activatable small molecule-based photosensitizers for precise cancer therapy

Photodynamic therapy (PDT) represents an innovative and highly promising modality for tumor treatment, attracting considerable attention within the medical community. However, it still faces several challenges, including limited selectivity, inadequate tissue penetration of light, and suboptimal generation of reactive oxygen species (ROS). The utilization of probes, which are activated by nitroreductase (NTR) , an enzyme that is overexpressed in hypoxic tumor tissues, for imaging and PDT represents a compelling strategy for diagnosing and treating cancerous tumors. In this review, we summarize and discuss the current progress in NTR-responsive photosensitizers for cancer imaging and therapy. We also discuss current challenges and perspectives for NTR-activatable photosensitizers. We believe these probes offer promising modalities for precise cancer therapy.