[Gene introduction into animal tissues by fusogenic liposomes]

The future success of gene therapy relies largely upon the development of ideal gene-transfer vehicles (vectors) that can efficiently and stably introduce and express therapeutic genes into non-dividing tissue cells. We have developed a fusogenic liposome that can deliver the encapsulated DNA into the cytoplasm through fusion with the cell membrane. For targeting the DNA into the nucleus, we attend to lambda phage particles that encapsulate up to 48 kbp DNA in their small head (55 nm in diameter). When a strong NLS signal is attached on the surface of the phage head by recombinant DNA technology, the particles efficiently accumulate in the nucleus. Reconstitution of the ideal gene-transfer system through a detailed analysis of biological phenomena is discussed.