Abstract: Objective: Discussing the inhibition mechanism on the nanometer hydroxyapatite solution (the nm-HAP-sol) on the skin squamous cell carcinoma cell line (A431). Methods: A431 cells were cultured with DMEM and the corresponding concentration of nm-HAP-sol in the 400mg/L. At the 1, 2, 3, 4, 5 days, observing the change of A431 cell morphosis during apoptosis through immunofluorescence microscopy and the variation of cell ultrastructure by transmission electron microscope. Result: It showed that there were few green fluor positive cells with irregular appearance at the 1, 2 days, double positive cells with green and red fluor emerged at the 3 day, there were many red fluor positive cells with crescent-shaped or massive caryotin assembling under the caryotheca at the 4, 5 days in experimental group through immunofluorescence microscopy. HAP nanoparticles appear at the 2 day of culture cells in experimental group by transmission electron microscope. It can be seen that cell morphology varied, cytoplasmic vacuolization, nucleolar cleavage, chromatin margination and partly cytoplasmic shedding. Conclusion: The HAP nanoparticles inhibited the generation of A431 cell by entering into the cell and effecting on the organelle and causing the generating cell apoptosis, oncosis and autoschizis.

Key words: cell proliferation