An in Vitro Study of the Fe2O3 Nanoparticles Effects on Calcium Homeostasis in Macrophage

[Objective] To investigate the changes of intracellular Ca(2+) ([Ca(2+)]i) in macrophage cells which were treated by Fe(2)o(3) nanoparticles, we conducted a series of experiments. [Methods] RAW264.7 cell was required in this study. The changes of [Ca(2+)]i in RAW264.7 cells was measured by laser scanning confocal microscope with Fluo-3/AM as the calcium fluorescent indicator. [Results] Fluorescent intensity in RAW264.7 cells at the dose of 1.0700mg/mL showed slightly raise, and the mean fluorescent intensity in RAW264.7 cells of 0.5350mg/ml, 0.2675mg/ml dose groups decreased at first and then raised. After 1 hours, the mean fluorescent intensity in RAW264.7 cells in all dosages show downtrend. After 6 hour's exposure, the mean fluorescent intensity began to increase. The mean fluorescent intensity of all dosages showed higher than control group(P<0.05)at the time of 1, 3, 12, 24 hours. The mean fluorescent intensity at the dose of 0.5350mg/ml showed higher than control group(P<0.05)at the time of 6 hours. [Conclusion] At the initial stage, the increase of [Ca(2+)]i levels may because of phagocytosis. But the subsequent increase may due to Fe(2)O(3) nanoparticles had broken the intracellular calcium homeostasis and led the intracellular calcium overloads.