Nanotechnology has seen many advances in recent years, both in terms of the development of novel materials, often with tunable properties and applications in a growing number of areas. An area of particular interest, and the topic of this book, is gene silencing. With the rapid development of nanotechnology in the recent decade, novel DNA and RNA delivery systems for gene therapy have become available that can be used instead of viral vectors. This book provides readers with a comprehensive review of various gene silencing methodologies and its applications.