Auger Electrons Constructed Active Sites on Nanocatalysts for Catalytic Internal Radiotherapy

Weiwei Su; Han Wang; Tao Wang; Xiao Li; Zhongmin Tang; Shuai Zhao; Meng Zhang; Danni Li; Xingwu Jiang; Teng Gong; Wei Yang; Changjing Zuo; Yelin Wu; Wenbo Bu

doi:10.1002/advs.201903585

Auger Electrons Constructed Active Sites on Nanocatalysts for Catalytic Internal Radiotherapy

Adv Sci (Weinh). 2020 Apr 6;7(10):1903585. doi: 10.1002/advs.201903585. eCollection 2020 May.

Authors

Weiwei Su¹, Han Wang^{2

3}, Tao Wang¹, Xiao Li¹, Zhongmin Tang^{2

3}, Shuai Zhao¹, Meng Zhang^{2

3}, Danni Li¹, Xingwu Jiang⁴, Teng Gong⁵, Wei Yang^{3

5}, Changjing Zuo¹, Yelin Wu⁴, Wenbo Bu^{3

5}

Affiliations

¹ Department of Nuclear Medicine Changhai Hospital Naval Medical University Shanghai 200433 P. R. China.
² University of Chinese Academy of Sciences Beijing 100049 P. R. China.
³ State Key Laboratory of High Performance Ceramics and Superfine Microstructures Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 P. R. China.
⁴ Tongji University Cancer Center Shanghai Tenth People's Hospital Tongji University School of Medicine Shanghai 200072 P. R. China.
⁵ Shanghai Key Laboratory of Green Chemistry and Chemical Processes School of Chemistry and Molecular Engineering East China Normal University Shanghai 200062 P. R. China.

Abstract

Excess electrons play important roles for the construction of superficial active sites on nanocatalysts. However, providing excess electrons to nanocatalysts in vivo is still a challenge, which limits the applications of nanocatalysts in biomedicine. Herein, auger electrons (AEs) emitted from radionuclide 125 (¹²⁵I) are used in situ to construct active sites in a nanocatalyst (TiO₂) and the application of this method is further extended to cancer catalytic internal radiotherapy (CIRT). The obtained ¹²⁵I-TiO₂ nanoparticles first construct superficial Ti³⁺ active sites via the reaction between Ti⁴⁺ and AEs. Then Ti³⁺ stretches and weakens the O-H bond of the absorbed H₂O, thus enhancing the radiolysis of H₂O molecules and generating hydroxyl radicals (•OH). All in vitro and in vivo results demonstrate a good CIRT performance. These findings will broaden the application of radionuclides and introduce new perspectives to nanomedicine.

Keywords: I‐125; active sites; auger Electrons; internal radiotherapy; nanocatalysts; titanium dioxide.