Studies On The Cytotoxicity Of Cationic Liposomes

In recent years, cationic liposomes mediated gene or drug delivery have been paid greatattention. However, cationic liposomes still have disadvantages of low cell transfectionefficiency and cell toxicity. It is still not very clear for the reason of the mechanism of toxicity.Therefore, elucidating cytotoxicity of the cationic liposomes has important theoreticalsignificance for their application.This paper studied the cytotoxic mechanism on human throat epidermis cancer cells (Hep-2)in vitro by cationic liposome DDCTMA liposome. The MTT method was used to test survivalrate of the cells with different concentrations of DDCTMA. The results show that with theincrease of the concentration of DDCTMA liposome, cell survivalrate decreased. It can causethe death of a large number of cells, when the concentration was high. The properconcentration of DDCTMA was selected to treat Hep-2cells, and the cells were treatal bylive cell/apoptosis/necrosis cell identification kits. The observation with inverted fluorescencemicroscope showed that DDCTMA liposome could induce Hep-2cells apoptosis. Themorphology of apoptotic cells was studied through Hoechst33258assay. The results showthat with the concentration increase of DDCTMA liposome, the number of apoptotic cellswent up. It can cause cell necrosis, when DDCTMA liposome concentration was high. Theenzyme activity analysis of Caspase-3and Caspase-9show that with the increase of theliposome concentration, the enzyme activity increased correspondingly, causing apoptosisreaction. The results show that DDCTMA liposomes can cause both of necrosis and apoptosisof Hep-2cells.