ABSTRACT
The advent of long-circulating, sterically stabilized liposomes has revitalized this field. It has now been demonstrated in several labs that antibody-directed targeting to cancer cells and endothelial cells can be achieved in vivo in the presence of sterically stabilizing groups on the liposome surface. A natural byproduct of the design of sterically stabilized liposomes (SL) was the application of this technology to the delivery of anthracyclines. A method for producing colloidal gold particles within liposomes was used recently to investigate the precise localization of liposomes in tumors and other tissues at the cellular level. The pharmacological studies of SL-DOX in rodents demonstrate reduced toxicity concomitant with increased tumor localization. Their results are consistent with the tumor localizing properties of the long-circulating vesicles. The use of conventional liposomes as a carrier system for drug delivery has already shown promising results, but has been limited to specific applications because of their short circulation time in blood.
