RESUMEN

Cationic liposomes,as non-viral vectors,are widely used in gene therapy and gene silencing.Although numerous cationic liposomes have various structures,they can all improve the per-formance of gene delivery.As gene therapy is increasingly studied,it may be foreseen that new cationic lipoplexes will be explored.In this review,we aim to discuss four constituent domains of cationic lipids(headgroup,hydrophobic domain,linker and helper lipids)in gene delivery.This article attempts to demonstrate that various lipid structures show different transfection efficiency and cytotoxicity by sum-marizing the similarities and differences between the four parts of cationic lipids.Furthermore,their major influencing factors are covered.Finally,three clinical cases of ionizable lipids are described to reveal their characteristics and differences from cationic lipids.This paper is intended to provide a conceptual framework for the design of cationic liposomes and for the selection of cationic lipids.