An artemisinin-mediated ROS evolving and dual protease light-up nanocapsule for real-time imaging of lysosomal tumor cell death

Lysosomes are critical organelles for cellular homeostasis and can be used as potential targets to kill tumor cells from inside. Many photo-therapeutic methods have been developed to overproduce reactive oxygen species (ROS) to trigger lysosomal membrane permeabilization (LMP)-associated cell death pathway. However, these technologies rely on extra irradiation to activate the photosensitizers, which limits the applications in treating deep seated tumors and widespread metastatic lesions. This work reports a multifunctional nanocapsule to achieve targeted lysosomal tumor cell death without irradiation and real-time monitoring of drug effect through encapsulating artemisinin and dual protease light-up nanoprobe in a folate-functionalized liposome. The nanocapsule can be specifically uptaken by tumor cells via folate receptor-mediated endocytosis to enter lysosomes, in which artemisinin reacts with ferrous to generate ROS for LMP-associated cell death. By virtue of confocal fluorescence imaging, the artemisinin location in lysosome, ROS-triggered LMP and ultimate cell apoptosis can be visualized with the cathepsin B and caspase-3 activatable nanoprobe. Notably, the artemisinin-mediated ROS evolving for tumor therapy and real-time therapeutic monitoring were successfully implemented by living imaging in tumor-bearing mice, which broaden the nanocapsule for in vivo theranostics and may offer new opportunities for precise medicine.