Cell Oxidative Stress Injury Induced by Cationic Liposomes

HAN Lei¹, CUI Shaohui¹^,2*, MA Qichen², CHEN Xingyan², WANG Yueying², ZHANG Shubiao²*

(¹College of Bioengineering, Dalian Polytechnic University, Dalian 116034, China; ²College of Life Sciences, Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, Dalian Minzu University, Dalian 116601, China)

Abstract:

As an important gene and drug carrier, synthetic cationic liposome has many advantages. Their clinical application was seriously limited due to unclear mechanism of cytotoxicity. This study investigated if oxidative stress in cells could lead to cytotoxicity. Human lung cancer NCI-H460 cells and human embryonic lung normal MRC-5 cells were used in the experiment. The cytotoxic mechanism of three cationic liposomes with different head structures were studied by CCK-8 assay, ROS (reactive oxygen species) fluorescent labeling morphological observation, flow cytometry quantitative determination and ROS free radical detection. The lipids used in this study were N,N-bis-decanethoxamide ethyl trimeric ornithine amide with tripeptide head (CDO14), N,N-bis-decaneth-oxamide ethyl-N,N-dimethyl ammonium iodide with mono quarterly ammonium salt head (CDA14) as well as 1,2-bis-[N-tetradecanoxamide ethyl-N,N-dimethyl ammonium iodide] ethane with diquaternary ammonium salt head (CTA14). The results showed that ROS level in the cells induced by three different head structures was proportional to the dose. ROS depending on the measurement of superoxide, hydrogen peroxide (H2O2), hydroxyl radical (•OH), and mono-oxidation nitrogen (NO) and malondialdehyde (MDA). High-concentration treatment group of CDA14 and CTA14 (0.10 μmol/L and 0.20 μmol/L) contrasted their low-concentration treatment group (0.05 μmol/L, conventional transfection concentration) and the blank control group had very significant difference, but CDO14 was only significant at the 0.20 μmol/L treatment group. Moreover, the oxidative stress damage of NCI-H460 cells was higher than that of MRC-5 cells. Therefore, oxidative stress injury of the peptide head liposome CDO14 was much smaller than the single quaternary ammonium salt liposome CDA14, and that CDA14 was smaller than the diquaternary ammonium salt liposome CTA14. In conclusion, cationic liposomes induced oxidative stress injury of cells is closely related to its head structure and dose. This study provides a scientific support for the biosafety of the cationic liposomes and the design of novel cationic lipid structures.