Efficient Photodynamic Therapy Nanocarriers with Oxygen Saving and Smart Releasing–Translocating Properties

Photodynamic therapy (PDT) is becoming a promising therapeutic technology for treating cancer diseases. However, its efficiency is usually affected by the hypoxic tumor microenvironment. Nanocarriers with the ability to relieve hypoxia have been widely investigated. Here, a new kind of PDT nanocarrier with oxygen saving ability was developed by functionally coassembling a mitochondrial-targeting photosensitizer and an inhibitor of mitochondrial respiration. The nanophotosensitizers were found to accumulate in lysosomes in the beginning. The acidic environment of lysosomes can break down the nanocarriers. The released photosensitizers can enter mitochondria. Meanwhile the released inhibitor can inhibit the glycolytic process and save oxygen for PDT occurring within mitochondria. The concordance of oxygen saving and smart releasing–translocating photosensitizers from lysosomes to mitochondria proved to be a good strategy for the enhancement of PDT efficiency.