Effect of hydroxyapatite nanoparticles on the ultrastructure and function of hepatocellular carcinoma cells in vitro

The interaction of Bel-7402 hepatocellular carcinoma cells (HCC) as a single cell suspension with hydroxyapatite (HAP) nanoparticles was investigated. It was observed by an inverted microscope that the cells were still homogeneously distributed in the culture medium after 24 h. A TEM analysis showed that the HAP nanoparticles attached to the Bel-7402 cells were finally swallowed by the cells after 4 h, and induced ultrastructural changes of the cells after 4 days. A MTT assay and cell count test for the HAP nanoparticles of various concentrations from 0.14 to 0.56 mmol L-1 showed that the HAP nanoparticles at a concentration of 0.56 mmol L-1 induced the strongest effect on the inhibition of Bel-7402 cell proliferation and induced a dramatic decline in cell numbers. Proliferation of Bel-7402 was inhibited by more than 70%, compared to the control. A cell cycle analysis revealed that HAP can arrest Bel-7402 cells at the G1 phase with increasing effect over time. These findings demonstrated that HAP can enter into HCC very easily, change their ultrastructure, and evidently suppress their proliferation.