Novel gene delivery to liver cells using engineered virosomes.

We have demonstrated for the first time that the reconstituted Sendai viral envelopes containing only the fusion protein (F-virosomes) are efficient vehicles for the delivery of foreign genes specifically into human hepatoblastoma cells (HepG2) in culture. The membrane fusion-mediated entry of CAT (chloramphenicol acetyl transferase) gene into the cells was confirmed and the amount delivered to various subcellular fractions was quantitated. The dose dependence and kinetics of expression of biologically active CAT protein in HepG2 cells was measured. The CAT expression level in F-virosome-mediated delivery was significantly higher than that of Lipofectin or liganded proteo-liposome-mediated gene transfer. This kind of targeted delivery by means of membrane fusion induced by viral envelope glycoprotein may have wide applications to various gene transfer strategies both in vitro and in vivo.