Design of Cerenkov Radiation-Assisted Photoactivation of TiO2 Nanoparticles and Reactive Oxygen Species Generation for Cancer Treatment.

Abstract

The use of Cerenkov radiation to activate nanoparticles in situ was recently shown to control cancerous tumor growth. Although the methodology has been demonstrated to work, to better understand the mechanistic steps, we developed a mathematic model that integrates Cerenkov physics, light interaction with matter, and photocatalytic reaction engineering. Methods: The model describes a detailed pathway for localized reactive oxygen species (ROS) generation from the Cerenkov radiation-assisted photocatalytic activity of TiO2 The model predictions were verified by comparison to experimental reports in the literature. The model was then used to investigate the effects of various parameters-the size of TiO2 nanoparticles, the concentration of TiO2 nanoparticles, and the activity of the radionuclide 18F-FDG-on the number of photons and ROS generation. Results: The importance of nanoparticle size in ROS generation for cancerous tumor growth control was elucidated, and an optimal size was proposed. Conclusion: The model described here can be used for other radionuclides and nanoparticles and can provide guidance on the concentration and size of TiO2 nanoparticles and the radionuclide activity needed for efficient cancer therapy.