Cytotoxicity of superparamagnetic iron oxide nanoparticles modified by chitosan or sodium oleate / 第二军医大学学报

ABSTRACT

Objective To investigate the cytotoxicity of superparamagnetic iron oxide nanoparticles (SPIONs) modified by chitosan or sodium oleate, so as to provide experimental evidence for future clinical application. Methods The morphology of chitosan-SPIONs or sodium oleate-SPIONs was observed by transmission electron microscope (TEM). Human lung adenocarcinoma A549 cells were treated with 10 μ/mL chitosan-SPIONs or sodium oleate-SPIONs; prussian blue staining was performed to observe the intracellular distribution of the two modified SPIONs. Chitosan-SPIONs or oleate-SPIONs of different concentrations (0, 25, 50, 100, and 200 μ/mL) were used to treat A549 cells and then MTT assay was used to detect cell proliferation. The activity of LDH in the supernatant of A549 cells was tested 48 h after treatment with chitosan- SPIONs or sodium oleate-SPIONs; furthermore, cell apoptosis was analyzed by DAPI staining. Results (1) Both the chitosan- SPIONs and sodium oleate-SPIONs exhibited structure of spherical crystallization, with a diameter of 20-30 nm. The thermal vibrational energy could overcome the magnetic attraction among the SPIONs, presenting superparamagnetism. (2) Prussian blue staining showed blue deposits in the cells, indicating that the two kinds of SPIONs entered the cytoplasm of A549 cells. (3) MTT assay results showed that chitosan-SPIONs hardly affected cell growth, while sodium oleate-SPIONs (200 μ/mL) inhibited the proliferation of A549 cells after 48 h and 72 h (P<0. 05). (4) The LDH activity in the supernatant of A549 cells treated with 200 μ/mL chitosan-SPIONs was significantly higher than that in the control group (P<0. 05), while the LDH activities in 100 μ/mL and 200 μ/mL sodium oleate-SPIONs groups were significantly higher than those in the control group (P<0. 05) and corresponding chitosan-SPIONs group(P<0. 05). (5) The results of DAPI dye showed no significant difference between the chitosan-SPIONs group and the control group, while the cells treated with sodium oleate-SPIONs displayed typical apoptosis characteristics, such as nuclear shrinkage and fragmentation, with the apoptosis rate being significantly higher than that of the control group(P<0. 05). Conclusion It is suggested that chitosan-SPIONs have slighter cytotoxicity to A549 cells compared with sodium oleate-SPIONs.