Advances in photodynamic therapy based on tumor hypoxia

Photodynamic therapy (PDT) has attracted wide attention due to its unique advantages such as minimal invasiveness, high efficiency and high selectivity, and its ability to induce anti-tumor immune response. However, the treatment process is heavily dependent on the oxygen content of the treatment site, and the widespread oxygen deficiency in malignant tumors severely limits its efficacy. In addition, PDT-mediated oxygen depletion exacerbates tumor hypoxia, which further reduces its therapeutic effect. In recent years, many researches have been devoted to overcoming this problem. This paper summarized various strategies based on tumor hypoxic PDT in recent years, discussing the advantages and disadvantages of these strategies, and analyzing the main challenges and future directions of PDT in the treatment of tumors, so as to provide references for the in-depth study of photodynamic therapy of tumors.