It has been over 100 years since Dr. Paul Ehrlich referred to an ideal therapeutic agent able to target and treat only a highly specific site in an organism in 1906: the so-called "magic bullet". The birth of new technologies, such as nanostructures, combined with the improved knowledge on the physiology and the biochemistry at the basis of human behaviour have opened completely new trails in medicine, making the research over drug delivery one of the most vital fields of science. This book presents a timely and informative summary of the current progress in a variety of subject areas, including medicine, chemistry, and biology. This book is written by experts in the field and serves as an indispensable reference to advanced researchers. The last advances in drug delivery, including nanoparticles, conjugated polyphenol, enhanced permeability and retention effect and also chimeric nanosystems, are addressed and provided by extensive and recent literature.