Recent advances in medicine and biotechnology have prompted the need to develop nanoengineered delivery systems that can encapsulate a wide variety of novel therapeutics. Moreover, these delivery systems should be “smart”, such that they can deliver their payload at a well-defined time, place, or after a specific stimulus. The ideal drug delivery system should be biodegradable and biocompatible, should benefit from an active and passive targeting, should target only the desired cells, and should release its cargo (high loading capacity) at the desired intracellular space. In addition, recent trends in nanotechnology have developed the concept of theranostic, i.e., imaging, therapeutic and diagnosis in one. To date, only a few examples of nanocarriers that fulfil all of these criteria have been reported and therefore this research field still remains almost unexplored. In addition, the application of all these concepts to polymeric nanogels constitutes nowadays a challenge, and the achievements of the proposed objective will pave the road for future biological and biomedical applications of these polymeric systems.