Abstract: Objective: To study the lethal effect of vitamin C carbon dots on oral squamous cell carcinoma KB cells, and to clarity its related mechanism.Methods: The KB cells were treated with different concentrations (5, 10, 20, 40 and 80 mg·L^-1) of vitamin C carbon dots in vitro as experimental groups, and 0 mg·L^-1 vitamin C carbon dots group was used as blank control group. MTT assay was used to detect the proliferation rates of KB cells in various groups; colony formation assay was used to detect the colony formation ability of KB cells; Western blotting was performed to detect the protein expression levels of autophagy related protein LC3 in KB cells in various groups; flow cytometry was used to detect the apoptotic rates of KB cells in various groups.Results: Compared with blank control group, the proliferation rates and colony formation abilities of KB cells in 20, 40 and 80 mg·L^-1 carbon dots groups were markedly decreased (P<0.01). Compared with blank control group, the protein expression level of LC3 Ⅱ in 40 mg·L^-1 carbon dots group was increased(P<0.05); the apoptotic rate of KB cells was markedly increased(P<0.01).Conclusion: Vitamin C carbon dots can kill the oral squamous cell carcinoma KB cells effectively, suppress the proliferation and impair the colony formation ability of KB cells, which is related to autophagy and apoptosis of KB cells.

Key words: vitamin C carbon dots, autophagy, mouth mucosa, apoptosis, carcinoma,squamous cell, proliferation