New approaches for the delivery of oligonucleotides (ODNs)

The aim of this paper is to review the most recent approaches for the transport and delivery of oligonucleotides (ODNs) in different biological systems with special regard to (a) alternative administration routes (with respect to the intravenous administration) and (b) strategies for ODN delivery based on polymeric particles. The key factors affecting macromolecule absorption have been of interest for many years in the field of drug delivery and targeting and in the production of macromolecular pro-drugs and specialized delivery systems. In this respect, it should be underlined that they are many factors that influence the extent and duration of biological activity following the administration of a gene medicine such as ODNs. Delivery is a fundamental component of activity, which we review here but the design and optimization of the nucleic acid molecule will also be a major part of the development of a successful gene medicine.