Fig. 2
From: Near-infrared photodynamic and photothermal co-therapy based on organic small molecular dyes
Schematic illustration of photodynamic reactions (either type I or type II) and cell death pathways in the process of PDT. A PS absorbs energy from light to kill tumor cells via ROS generation. The PDT-induced modes of cell death, including apoptosis, necrosis, necroptosis, and autophagy, depend on the cell type, PS type or concentration, intracellular localization, light dose, and oxygen partial pressure [77]