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

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.

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.

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.