Polymeric nanodevices as delivery systems for nucleic acid based drugs

The advances of Nucleic Acid Based Drugs (NABDS) mediated therapy and in particular of short interfering RNA (SIRNA) provide a powerful option for treatment of many diseased by silencing the expression of targeted genes including cancer development and progression. Despite their high therapeutic potential, SIRNAS suffer from degradation by ubiquitous RNase and moreover their high molecular weight, hydrophilicity, and negative charge prevent siRNA from adequately penetrating cell membranes. Therefore, effective carriers which can protect siRNA from degradation and facititate their delivery to the cytosol are crucial to effective RNAI therapy. But in order to obtain efficient siRNA formulations some other topics concerning blood circulation time, extracellular barriers, evading the immune as well as the development of effective siRNA dosage forms should be focused. Polysaccharides and polyaminoacids can be used as starting materials to produce biocompatible functionalized copolymers able to efficiently complex nucleic acids and to deliver them into cells. Positive aspects and failings of some family of these copolymers will be discussed with reference with main obstacles of siRNA therapy