Series of lipids 1a-d and 2a,b, with carbamate linkages between hydrocarbon chains and ammonium or tertiary amine head, which were pH sensitive, were synthesized for liposome-mediated gene delivery. The variable length of carbon chains and quaternary ammonium or neutral tertiary amine heads allowed to find the structure-function relationship of how these factors affect cationic lipids on gene delivery performance. (c) 2005 Elsevier Ltd. All rights reserved.

The composition and the structure of cationic liposomes and its application in gene therapy as gene delivery are introduced. The research on the mechanism of cationic liposomes transgenosis is stated, showing the entry of cationic liposomes and DNA complexes into cell depends on the structure of cationic liposomes, endocytosis or fusion with cell membrane.

The basic concept, forming mechanism and manufacture of liposomes are introduced. Liposomes originate from amphiphiles and self-assembly, so it is of great importance to study the theory of self-assembly for the production of liposomes.