Distearoylphosphatidylethanolamine-based liposomes for ultrasound-mediated drug delivery.

The ability of ultrasound (US) to permeabilize phospholipid membranes has opened the potential of using US as a means to enhance delivery of anti-cancer drugs to tumour cells via liposomes. In this study, novel US sensitive or sonosensitive doxorubicin-containing liposomes based on 1,2 distearoyl-sn-glycero-3-phosphatidylethanolamine (DSPE) as the main lipid component are reported. A variety of lipid bilayer compositions was studied with respect to in vitro US triggered release of drug as well as serum stability in terms of drug retention, using experimental design. The multivariate data analysis indicated a strong correlation between DSPE content and sonosensitivity, both alone and in interplay with cholesterol. The most optimal formulation showed approximately 70% release of doxorubicin after 6min of US exposure. This represented a 7-fold increase in release extent when compared to standard pegylated liposomal doxorubicin. The significant enhancement in sonosensitivity of the liposomes shows the potential of engineering liposomal lipid composition for US-mediated drug delivery.