Electron Irradiation Effects on N and Fe3+ Doped Carbon Dots and the Application in Radiotherapy of Lung Cancer

Han Bai,1,2 Jin Zhang,1,3 Yuzhao Li,1 Weizuo Zhang,1 Zhexian Zhao,1 Ju Tang,4 Wen Xu,1,5 Yiming Xiao1 1School of Physics and Astronomy, Yunnan University, Kunming, Yunnan Province, People’s Republic of China; 2Department of Radiation Oncology, Yunnan Tumor Hospital, Kunming, Yunnan Province, People’s Republic of China; 3Yunnan Carbon Based Technology Co., Ltd., Kunming, Yunnan Province, People’s Republic of China; 4School of Electrical and Information Technology, Yunnan Minzu University, Kunming, Yunnan Province, People’s Republic of China; 5Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, Anhui Province, People’s Republic of ChinaCorrespondence: Yuzhao Li, Email [email protected] Yiming Xiao, Email [email protected]: Carbon dots (CDs) have great potential application in disease treatment, but there were rare detailed reports on the application of CDs in radiotherapy so far.Methods: In this study, N and Fe3+ doped CDs (N-Fe-CDs) were prepared with a one-step hydrothermal method. The properties of N-Fe-CDs before and after 10 MeV electron beam irradiation (EBI) were characterized by TEM, XRD, XPS, FT-IR, and PL. Cell toxicity experiments and irradiation experiments on tumor-bearing mice were conducted to explore the EBI effects and N-Fe-CDs for the efficacy of the synergistic treatment of lung cancer.Results and Discussion: The fluorescence intensity of N-Fe-CDs was significantly weakened after EBI. When the N-Fe-CDs’ concentration was ≤ 2.7 × 10− 2 mg/mL, its cytotoxicity was almost zero. The tumor regression in the “CDs solution injection followed by EBI” group was significantly greater than other groups. EBI can weaken fluorescence of the N-Fe-CDs and the N-Fe-CDs can enhance the therapeutic effect of electron beam therapy for lung cancer.Keywords: N-Fe-CDs, electron irradiation effect, radiation sensitization, fluorescence imaging