Targeting of liposomes to hepatocytes.

We began our investigations about 15 years ago with the concept that it should be possible to deliver drugs or enzymes intracellularly into lysosomes for diseases associated with lysosomal enzymes (e.g., sphingolipidosis). The results have been very gratifying. It now has been possible to extend our in vitro studies on the kinetics of lectin-liposome interaction to the targeting of glycolipid liposomes to specific liver cell types in vivo by simply varying the sugar residue on the surface of liposome. Nevertheless, much remains to be done to ascertain the stability of the external enzyme and the expression of its activity after the delivery into the lysosomes.