Recent advances in nanophotosensitizers for overcoming tumor hypoxia in photodynamic therapy

consumption during PDT exacerbates tumor hypoxia, which in turn accelerates tumor progression and contributes to suboptimal therapeutic outcomes. To mitigate this challenge, recent advancements in nanotechnology have facilitated the development of nano-photosensitizers (nano-PSs) capable of alleviating hypoxic TME through a variety of strategies. This review provides an overview of recent advancements in PDT strategies aimed at overcoming tumor hypoxia, which encompass: (1) alleviating hypoxia, (2) utilizing hypoxia, (3) regulating the hypoxic TME, and (4) designing type-I PSs. Through a review of recent advancements, this work seeks to offer insights into the design of nano-PSs that can mitigate hypoxia-related limitations in PDT, while also highlighting future opportunities and challenges for clinical translation.