Functional lipids and lipoplexes for improved gene delivery

► The recent research activities using functional lipids for gene delivery are reviewed. ► The barriers to efficient gene delivery are described. ► The pathways and mechanism(s) of lipoplex uptake in cells are reported. ► Functional lipids deliver DNA more efficiently than analogs that do not. ► Functional lipids show significant promise for in vitro and in vivo gene transfection.