Effect of DNA complexation and freeze-drying on the physicochemical characteristics of cationic liposomes

This paper describes the use of some saccharides, such assorbitol, mannitol, sucrose, maltodextrin and dextran, as cryoprotectantsfor the freeze-drying of cationic liposomes. Saccharides can in fact protectliposomes either by interacting with phospholipids headgroups or by forming an amorphous glass sorrounding the vesicles, thus preventing aggregation,mechanical breaking of membrane, fusion of liposomes and drug leakage. Particularly, some liposomecharacteristics, such as size, zeta potential and ability in complexing DNA, before and after freeze-drying have been considered. Our studyindicates that cationic liposomes are able to maintain the liposomes characteristics after lyophilization and rehydration andmaintain the ability to complex DNA even if the strenght of the interactionforces resulted of lower intensity with respect to liposomes before lyophilization.