Nanomedicine technology: Current achievements and new trends

Nanomedicines consist of biodegradable or biocompatible submicron-sized colloidal particles encapsulating a drug. Nanomedicine technology has emerged following pioneering work in the 1970s and has given rise to an enormous number of novel delivery systems and applications. Advances in chemistry and engineering have yielded a large panel of biocompatible and biodegradable materials from which nanomedicines can be made. We briefly review the main different types of existing nanomedicines, focusing particularly on those used in the clinic. We then examine the biological barriers nanomedicines must cross to reach their target after intravenous injection, and how these barriers can be overcome. Although mostly conceived for intravenous administration, nanomedicines hold potential for delivery by other routes, such as the oral, ocular and pulmonary routes, which we examine. Finally, we focus on new trends in nanomedicine technology such as stimuli-responsive nanomedicines and the combination of nanomedicines with imaging agents to yield the so-called nanotheranostics. © 2014 Italian Association of Nuclear Medicine and Molecular Imaging.