1. Academic Validation
  2. Amplifying X-ray-Induced Charge Transfer Facilitates Direct Sensitization of Photosensitizers in Radiotherapy

Amplifying X-ray-Induced Charge Transfer Facilitates Direct Sensitization of Photosensitizers in Radiotherapy

  • ACS Nano. 2025 May 6;19(17):16775-16793. doi: 10.1021/acsnano.5c01506.
Da Zhang 1 2 Qingjing Chen 1 2 Junrong Zhang 3 Xiaohua Xing 1 4 Yang Zhou 1 2 Xiangyu Ou 5 Shuheng Dai 4 Qiushui Chen 4 Xiaolong Liu 1 6 2 Xiaoyuan Chen 7 8 9 Yongyi Zeng 1 10
Affiliations

Affiliations

  • 1 The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, P. R. China.
  • 2 Mengchao Med-X Center, Fuzhou University, Fuzhou 350116, P. R. China.
  • 3 Department of General Surgery, Fujian Medical University Union Hospital, Fuzhou 350001, P. R. China.
  • 4 MOE Key Laboratory for Analytical Science of Food Safety and Biology, Fuzhou University, Fuzhou 350108, P. R. China.
  • 5 Department of Physics, Chemistry and Biology (IFM), Linköping University, Linköping SE-58183, Sweden.
  • 6 CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
  • 7 Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and Faculty of Engineering, National University of Singapore, Singapore 119074, Singapore.
  • 8 Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 138667, Singapore.
  • 9 Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 138667, Singapore.
  • 10 Liver Disease Center, The First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, P. R. China.
Abstract

X-ray-induced photodynamic therapy offers substantial promise for treating deep-seated tumors, but it is still limited by highly inefficient energy transfer processes and the stringent requirements for scintillators with high luminescence quantum yield and significant singlet-triplet intersystem crossing ratios. Herein, we describe X-ray-induced electron-dynamic therapy (X-eDT), which obviates the need for intersystem crossing by exposing nonluminescent hafnium-silica nanoparticles to X-rays, to generate high-energy electrons that can sensitize lower-lying triplet states of various photosensitizers. Our approach strongly induced the production of singlet oxygen (6.18-fold) in vitro even at lower X-ray doses, and in mice it strongly inhibited the growth of xenografts derived from liver, breast, or colon Cancer cell lines (CDX), and growth of patient-derived xenografts (PDX) of hepatocellular carcinoma. In these CDX preclinical systems, X-eDT was not only effective against the irradiated xenograft but also against untreated xenografts in the same animal, and these abscopal effects involved enhanced tumor infiltration by CD4+T cells, CD8+T cells, and IFN-γ-polarized M1 macrophages within the tumor microenvironment. X-eDT even stimulated the production of memory T cells that inhibited rechallenges after treatment. These findings suggest that X-eDT can be effective against primary and metastatic tumors as well as tumor recurrence, which makes it much more powerful than conventional X-PDT.

Keywords

X-ray-induced electron-dynamic therapy; abscopal effect; immunity; metastatic cancer; radiosensitizer; radiotherapy.

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