Abstract: OBJECTIVE: To explore the transfection effects and cell toxicity of mock miRNA at different concen- trations, liposome at different concentrations and different transfection times in human bronchial epithelial cells in vitro and optimize transfection conditions. METHODS: 16-HBE cells were incubated with 0, 10, 30 and 50 nmol/L Cy3 labelled mock miRNA and 0, 0.1％, 0.3％ and 0.5％ liposome. The transfection effects in the cells were examined by fluorescence microscopy and were evaluated by fluorescence intensity analysis after 6, 12 and 24 h of transfection. Cell activity was measured after 24 h transfection with different transfection conditions by WST-8 method. RESULTS: Intracellular fluorescence intensity was enhanced with increasing mock miRNA and liposome concentration and transfection time. The transfection effects of 30 and 50 nmol/L mock miRNA transfection groups was significantly higher than 10 nmol/L mock miRNA transfection group(P<0.05). The transfection effects of 0.3％ and 0.5％ liposome groups were obviously higher than 0.1％ liposome groups(P<0.05). Intracellular fluorescence intensity after 24 h transfection was remarkably increased those that after 6 and 12 h transfections(P<0.05). There was no significant difference in cell toxicity between transfection groups and control group(P>0.05). CONCLUSION: 16-HBE cell could be used in the research of liposome-mediated delivery of mock miRNA. Mock miRNA and liposome concentration and transfection time are important influence factors of transfection. Optimal transfection effects could be obtained after 24 h transfection with 30 nmol/L mock miRNA and 0.3％ liposome. There was no effect on the cell activity after transfection.

Key words: human bronchial epithelial cells, miRNA, liposome, transfection