초록 |
Tumor microenvironment involves more vigorous redox signaling than normal cells, which has led to the development of cancer-specific degradable nanocarriers for cytotoxic anticancer drugs. Herein, we considerably improved the cancer-specific cytotoxicity of iridium complex-based photosensitizer (TIr3) by enhancing degradation sensitivity of nanogel (IrNG) through disrupting its disulfide bonds, reflecting the irreversible oxidation of intracellular glutathione by reactive oxygen species (ROS). The encapsulated TIr3 generates excessive ROS upon exposure to extremely weak light (0.25 J/cm2), efficiently degrading IrNG. The released cytotoxic TIr3 induces cancer cell apoptosis in in-vitro and in-vivo experiments. In contrast, IrNG shows high biocompatibility in the dark, even when exposed to high glutathione levels. This photosensitizer-produced ROS-mediated irreversible breakdown of IrNG provides new insight for designing unexplored cytotoxic photosensitizer-customized nanocarriers. |