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

Introduction: 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 Fe 3+ 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