LAUSR

The development of biocompatible and efficient photocatalytic redox systems to mimic bio‐photoreactors in living cells holds great potential for manipulating intracellular biochemical reaction processes and thus advancing tumor therapy. In this study, a mitochondria‐targeted photoredox catalyst, 2D vacancy‐rich molybdenum oxide nanosheets (Mt‐VR‐MoO3) is presented. These nanosheets possess a high density of oxygen vacancies (19.2%) and exhibit strong photocatalytic redox activity under near‐infrared (NIR) light. Following a two‐step functionalization, Mt‐VR‐MoO3 effectively disrupts mitochondrial electron flow in an oxygen‐independent manner upon irradiation with second near‐infrared (NIR‐II) light. This targeted disruption leads to on‐demand induction of substantial damage to tumor cell mitochondria, characterized by increased production of mitochondrial reactive oxygen species (mtROS) and the release of cytochrome c (Cyt c), which collectively trigger the pyroptosis of cancer cells. The approach achieved tumor‐targeted photocatalytic eradication with high efficacy (tumor growth inhibition rate of 86.9%) in an orthotopic breast 4T1 murine tumor model, with no observable harm to normal organs. These findings provide inspiration for manipulating intracellular biochemical reactions using artificial photocatalytic materials, paving the way for pyroptosis activation as a promising approach in tumor therapy.