Compositions and methods for improved delivery of macromolecules into eukaryotic cells are provided. Fusogenic peptides from fusion proteins of non-enveloped viruses enhance the efficiency of transfection of eukaryotic cells mediated by transfection agents such as cationic lipids, polycationic polymers such as PEI and dendrimers. These fusogenic peptides are used as part of a transfection complex that efficiently delivers a macromolecule, for example, a nucleic acid, into a eukaryotic cell. Novel cationic o lipids and compositions of cationic lipids also are provided that may be used for the introduction of macromolecules such as nucleic acids, proteins and peptides into a variety of cells and tissues. The lipids can be used alone, in combination with other lipids and/or in combination with fusogenic peptides to prepare transfection complexes.
