Abstract A highly efficient photochromic hydrogel was successfully fabricated via casting precursor, which is based on amorphous tungsten oxide and poly (ethylene oxide)- block -poly (propylene oxide)- block -poly (ethylene oxide). Under simulated solar illumination, the hydrogel has a rapid and controlled temperature increasing ratio as its coloration degree. Localized electrons in the amorphous tungsten oxide play a vital role in absorption over a broad range of wavelengths from 400 nm to 1100 nm, encompassing the entire visible light and infrared regions in the solar spectrum. More importantly, the material exhibits sustainable released H 2 O 2 induced by localized electrons, which has a synergistic effect with the rapid surface temperature increase. The amount of H 2 O 2 released by each film can be tuned by the light irradiation, and the film coloration can indicate the degree of oxidative stress. The ability of the H 2 O 2 -releasing gels in vitro study was investigated to induce apoptosis in melanoma tumor cells and NIH 3T3 fibroblasts. The in vivo experimental results indicate that these gels have a greater healing effect than the control in the early stages of tumor formation.
