Arsonoliposomes for drug delivery applications

Arsonoliposomes are arsenic-containing liposomes that incorporate novel arsenic-containing lipids (arsonolipids) in their lipid bilayers. In vitro and in vivo studies have demonstrated that some arsonoliposome types have interesting anticancer and antiprotozoal activity. Their anticancer activity may be linked with the reduction of their arsenic content to its more toxic form (from As[V] to As[III]). This reduction is enhanced in areas where increased concentrations of thiol-containing compounds (such as glutathione) prevail (which is the case for some types of cancer cells). The physicochemical characteristics, the in vivo distribution and kinetics and the antiprotozoal activity of arsonoliposomes were found to be influenced by the lipid composition of their membrane, while their anticancer activity was minimally - if at all - affected. Currently, the in vivo activity and toxicity of specific arsonoliposome types is being evaluated in in vivo cancer models, while combinations of arsonoliposomes with cytotoxic agents are being evaluated in vitro.