Liposomes for the delivery of nucleotides and oligonucleotides

Adenosine triphosphate (ATP) and antisense oligonucleotides are molecules that are highly polar negatively charged with a very poor cellular uptake. In addition, both ATP and oligonucleotides are unstable in biological fluids. Nevertheless, they are both responsible for several pharmacological effects which can be used in therapeutics. ATP can constitute a possible bioenergetic substrate used in various medical applications and antisense oligonucleotides, being able to inhibit gene expression, can be useful for the treatment of viral infections nod oncogene-induced tumors. To try to develop a system able to protect nucleotides and oligonucleotides against degradation and to efficiently deliver them to their cellular target, we have used liposomes as carrier. This review focuses on both approaches under development in our group to use liposomal ATP for the treatment of brain ischemia and sperm cells,motility. We also discuss the advantage of using pH sensitive liposomes containing antisense oligonucleotides against the mRNA of the Friend retrovirus.