Site-specific drug delivery and targeting has attracted much research interest from both academia and industry, but because of the wide array of challenges faced in the development of these systems, only a very few targeted therapies have made it to clinics. Bringing together key research, this volume summarizes current progress with a focus on the novel ideas that are being explored to overcome these challenges. This forward-looking volume includes an in-depth review of various aspects of these drug delivery approaches as well as a detailed discussion of a few case studies in each category.