(A) Intracellular accumulation enhancement of PpIX induced by various drugs (CA, DFO, HA@CA, H2O2 and Fe2+) with different concentrations. (B) The intracellular ROS generation in B16F10 cells treated with various concentration of CA (0-150 µM) for 8 h, and (C) treated with 100 µM CA for different times (0, 4 and 8 h). (D) Flow cytometric analysis of intracellular ROS generation after different treatments under dark, and (E, F) with NIR laser irradiation. (G) CLSM observation of intracellular ROS generation after different treatments with NIR laser irradiation (Scale bar: 30 µm).