The local hypoxic
tumor environment substantially hampers the therapeutic efficiency of
radiotherapy, which typically requires the large X-ray doses for
tumor treatment but induces the serious side effects. Herein, a biomimetic radiosensitized platform based on a natural in-situ
oxygen-evolving photosynthetic cyanobacteria combined with two-dimensional (2D) bismuthene with high atomic-number (Z) components, is designed and engineered to effectively modulate the
radiotherapy-resistant hypoxic
tumor environment and achieve sufficient radiation energy deposition into
tumor. Upon the exogenous sequential irradiation of 660 nm
laser and X-ray beam, continuous photosynthetic
oxygen evolution by the cyanobacteria and considerable generation of
reactive oxygen species by the 2D bismuthene radiosensitizer substantially augmented the therapeutic efficacy of
radiotherapy and suppressed the in vivo
tumor growth, as demonstrated on both LLC-lung
tumor xenograft-bearing C57/B6 mice model and 4T1-breast
tumor xenograft-bearing Balb/c mice model, further demonstrating the photosynthetic
hypoxia-alleviation capability and radiosensitization performance of the engineered biomimetic radiosensitized platform. This work exemplifies a distinct paradigm on the construction of microorganism-enabled tumor-microenvironment modulation and nanoradiosensitizer-augmented
radiotherapy for efficient
tumor treatment.