**1. Introduction**

480 Non-Viral Gene Therapy

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Nanomedicine has the potential of clinical benefit by combination of engineering technologies and materials (Schatzlein, 2006). Development of nanometre scaled therapeutics which provides new and improved properties by specifically targeting the site of action and causing low level of side effects would be a big challenge to treat patients with severe and live-threatening diseases like cancer. Gene therapy provides a new way to treat patients and a lot of effort is made to improve the clinical benefit. But current gene therapy is still experimental and has not proven success in the clinics. Nevertheless there is a need for new approaches to treat "undruggable" disease sites and there are some clinical trials ongoing which using RNA inference (RNAi) as therapeutic mechanism (Table 1).
