Photodynamic Therapy for Solid TumorTherapy: No Longer Restricted by Hypoxia

Photodynamic therapy (PDT), a minimally invasive treatment modality for cancer, involving the formation of reactive oxygen species (ROS) and subsequently eradication of the tumorous cells, has received a great attention. However, its oxygen-dependent nature to certain degree limits PDT from achieving satisfactory outcomes in solid tumors because of the frequent hypoxia circumstances. To alleviate hypoxia, efforts have been made through diversified strategies, e.g., delivery of ecdemic oxygen and intracellular replenishment of oxygen during PDT. In this mini review, we further elaborate on the details of these strategies and corresponding mechanisms for better therapy efficacy.