Arsonolipids are synthesized lipids (Tsivgoulis GM et al., Phosphorus, Sulfur and Silicon 1991, 57, 189) which have novel characteristics compared with phospholipids or phosphonolipids. These lipids (1,2-diacyloxypropyl-3-arsonic acids) are analogues of phosphonolipids in which As is replacing P in their polar head group (see below).
Phospholipids (left) - Arsonolipids (right)
The most important difference in
respect of their in-vivo behavior is probably the fact that the AsO3H2
group can be reduced very easily by biologically important thiols (Timotheatou
D et al., Metal-Based Drugs 3, 263).
It has been found that arsonolipids form tubules or disk-shaped liposomes, when dispersed alone in aqueous media but form conventional liposomes (arsonoliposomes) when phosphatidylcholine and/or cholesterol are added. These latter liposomes can be used either empty or loaded with drugs.
Investigations on malignant cells reveal that arsonoliposomes cause a dose- and time-dependent inhibition of survival in three malignant cell lines. No significant effect on the survival of the normal cells was observed (Gortzi O et al., Pharm Res 2002, 19, 79). It was later determined that palmitoyl-arsonolipid arsonoliposomes should be used for further investigations in vivo towards the development of an anticancer product (Gortzi O et al., Eur J Pharm Sci 2003, 18, 175). Furthermore, arsonoliposomes could be of value for anti-protozoal therapy as they show some antileishmanial and trypanocidal activities (Antimisiaris SG et al., J Pharm Pharmacol 2003, 55, 647). So far, from numerous studies it can be concluded that arsonoliposomes are nanosized-vesicles with interesting properties that justify further exploitation towards the development of therapeutic systems for cancer or parasitic diseases (Fatouros DG et al., J Nanosci Nanotechnol 2006, 6, 2618).