Study On Toxicity Of Liver Cells Induced By Iron Oxide Nanoparticles

In this study, human hepatic cell line HL-7702 was used as model, the cytotoxicity of iron oxide nanoparticles was observed by CCK-8 assay and LDH release assay; the lipid peroxidation effect was examined by biochemical method; DNA damage was measured by SCGE assay; the changes of cell cycle and cell apoptosis was detected by flow cytometry (FCM). The experimental results of the study were shown as follow:1. the cytotoxicity of HL-7702 induced by iron oxide nanoparticlesCCK-8 assay was performed to detect the cytotoxicity after exposure to iron oxide nanoparticles (75, 150, 300 and 600μg/mL) for 24 h. The results showed that the survival rate was decreased with the increase dosage of iron oxide nanoparticles. It was significant difference between 150, 300, 600μg/mL groups and control group respectively (P<0.05). In recovery assay, cells for 48 h, there were significant difference between all exposure group and recovered group respectively (P<0.05), the survival rate of 150μg/mL group was close to that of control group, the survival rate of 300 and 600μg/mL group was obviously lower than that of control group (P<0.05). LDH release assay was used to detect the cytotoxicity after exposure to iron oxide nanoparticles (75, 150, 300 and 600μg/mL)for 24 h. LDH level in cell culture medium apparently increased with the increase dosage of iron oxide nanoparticles (P<0.05). The results suggest that iron oxide nanoparticles could damage the membrane of HL-7702 cells.and had the inhibitory effect on HL-7702 cell proliferation.2. Lipid peroxidation of HL-7702 induced by iron oxide nanoparticlesAfter exposure to iron oxide nanoparticles (75, 150, 300 and 600μg/mL) for 24 h, SOD,GSH-Px activity decreased with the increace dosage of iron oxide nanoparticles, MDA content increased with the increase dosage of iron oxide nanoparticles, there were significant differences between exposure groups and control group respectively (P<0.05). The results suggest that iron oxide nanoparticles could induce lipid peroxidation on HL-7702 cells.3. DNA damage in HL-7702 induced by iron oxide nanoparticlesSingle cell gel electrophoresis (SCGE) assay was used to measure DNA damage of HL-7702 cells. After exposure to iron oxide nanoparticles (75, 150, 300 and 600μg/mL) for 24 h, It was showed the DNA damage rate increased with the increase dosage of iron oxide nanoparticles. there were significant difference between 150, 300, 600μg/mL groups and control group respectively (P<0.05). The results suggest that iron oxide nanoparticles could induce the damage of DNA in HL-7702 cells.4. Cell cycle changes of HL-7702 induced by iron oxide nanoparticlesFCM with PI staining method was performed to detect the cell cycle changes. After exposure to iron oxide nanoparticles (75, 150, 300 and 600μg/mL) for 24 h, the percentage of cells in G0/G1 phase increased, while the rate in S phase decreased with the increase dosage of iron oxide nanoparticles (P<0.05). All suggested iron oxide nanoparticles could induce G0/G1 phase arrest, decreased cells population in S phase, accordingly interfered the process of DNA synthesis.5. Apoptosis of HL-7702 induced by iron oxide nanoparticlesFCM with PI staining method were performed to detect apoptosis. After exposure to iron oxide nanoparticles (75, 150, 300 and 600μg/mL) for 24 h, apoptotic rate ascended with the increasing of iron oxide nanoparticles. there were significant difference between 150, 300, 600μg/mL groups and control group respectively (P<0.05). The results suggest that iron oxide nanoparticles could induce apoptosis of HL-7702 cells.All in all, iron oxide nanoparticles could induce the cell toxic effects on HL-7702 cells, including decreasing the activity of anti-oxidative enzyme(GSH-Px,SOD), increasing the concent of MDA, inducing lipid peroxidation; impacting the progress of cell cycle; inducing cell apoptosis. The research has the important theoretical meaning in studuying the toxic effects of SPION on liver and in investigating its toxic mechanism. which provide experimental basis for safety evaluation of iron oxide nanoparticles.