Near-Infrared Light-Enhanced Generation of Hydroxyl Radical for Cancer Immunotherapy

Hydroxyl radical (^• OH) as a highly oxidizing reactive oxygen species can induce immunogenic cell death (ICD) in cancer treatment. However, high-efficiency cancer immunotherapy is still a huge challenge due to the low ^• OH generation efficiency in the tumor microenvironment, resulting in insufficient immunogenicity and the poor immune response. Here, a near-infrared (NIR) light-enhanced ^• OH generation strategy is developed for cancer immunotherapy by using a copper-based metal-organic framework (Cu-DBC) nanoplatform. With this strategy, the generation efficiency of ^• OH under NIR irradiation is increased 7.34 times than that without NIR irradiation, which induces robust ICD and immune response, thus leading to primary tumor elimination and the inhibition of distant tumor growth and tumor lung metastasis. Experimental results show that Cu-DBC can induce ^• OH boosting through photothermal (PT)-enhanced Cu-catalytic Fenton-like reaction and photocatalytic electron transfer under NIR light irradiation to amplify tumor ICD for immunotherapy.