2240 - The Synthesis of Bi₂S₃-CeO₂@Phe and its Radiosensitization and Radiation Protection to Esophageal Cancer

L. Chen¹, Z. Wang¹, T. Zhang¹, W. Wang¹, X. H. Sun¹, J. Duan¹, Y. Gao¹, H. Zhang², and L. Zhao¹; ¹Department of Radiation Oncology, Xijing Hospital, Fourth Military Medical University, Xian, Shaanxi, China, ²Ministry of Education Key Laboratory of Intelligent and Network Security, Faculty of Electronics and Information Engineering, Xi’an Jiaotong University, Xian, Shaanxi, China

Purpose/Objective(s): The damage of radiotherapy to normal tissues and the recurrence after radiotherapy of the esophageal are still clinical problems. A new nanomaterial, Bi₂S₃-CeO₂@Phe, with both radiosensitization and radiation protection properties, is developed to solve these problems. Materials/

Methods: The Monte Carlo simulation is used to obtain the optimal X-ray irradiation energy and the optimal particle size of the nanomaterial. Then, the Bi₂S₃-CeO₂@Phe is synthesized, which combines photothermal therapy (Bi₂S₃), catalytic therapy (CeO₂), and targeted drug Phe. Connecting to CeO₂ by chemical bonds, the targeted drug Phe can improve the targeting and reduce the toxic effects of CeO₂. The Bi₂S₃-CeO₂@Phe nanomaterial has the characteristics of low toxicity, high targeting, radiosensitization and radiation protection. The structure, performance and curative effect of the Bi₂S₃-CeO₂@Phe nanomaterial are verified by optical tests and biological experiments.
Results: By Monte Carlo simulation, the optimal particle size of the Bi₂S₃-CeO₂@Phe nanomaterial is 53.2 nm, and the optimal X-ray irradiation energy is 100 KeV. The observed results, e.g. the crystallinity, structure and composition, from scanning electron microscopes, transmission electron microscopes, X-ray diffraction spectrums and infrared spectrums show that the successful synthesis of the Bi₂S₃-CeO₂@Phe nanomaterial. UV-vis spectrums indicate that the nanomaterial has remarkable photothermal features, and the photothermal conversion efficiency can be improved to 49.3%. Biological experiments show low toxicity to the normal tissues, high targeting and the excellent radiosensitization and radiation protection properties compared with eleven control groups.
Conclusion: The synthetic Bi₂S₃-CeO₂@Phe nanomaterial could protect the normal tissues during radiotherapy and reduce the recurrence after radiotherapy, and has a great potential to be applied to other disease sites.