This chapter will review the use of engineered nanoparticles (NPs) for nanomedicine providing an overview of design, properties, and functions of a variety of NPs along with their medical applications (especially focusing on innovative drug delivery strategies). Examples provided will span from NPs, which have been already translated in clinics (NPs therapeutics) to complex multifunctional and biological responsive nanostructures (biomimetic and bioactive NPs) whose medical translation is still in its infancy. The enormous impact of multifunctional NPs-based therapy will be highlighted taking in mind the regulatory requirements for nanomedicine.