Electrochemiluminescence Drives Photodynamic Therapy In Vivo

Electrochemiluminescence (ECL) holds significant promise in the biomedical field, but remains a challenge for in vivo photodynamic therapy (PDT). Herein, a wearable light source of ECL to drive PDT (ECL-PDT) is developed, in which a flexible ECL device (ECLD) is fabricated using an ECL gel containing Ru(bpy)₃Cl₂ as the light-emitting layer positioned between two transparent indium tin oxide-coated substrates. By applying alternating current voltage, Ru(bpy)₃ ⁺ and Ru(bpy)₃ ³⁺ are alternately generated within the ECLDs, and then collide to produce excited species, followed by high-efficiency and stable ECL emission. The ECLDs can further activate photosensitizers to produce reactive oxygen species through a resonance energy transfer process, ultimately leading to oxidative damage of cancer cells. As a result, such ECLDs demonstrate excellent antitumor efficacy on cells, and tumor growth is distinctly inhibited in a tumor-bearing mouse model. This work not only provides a convenient and effective ECL-PDT strategy for cancer treatment, but also expands the application of ECLD as a wearable photonic healthcare device.