Nanoparticles as therapeutic agents. Expectations, reality and perspectives

Abstract

Nanotechnology has opened up new perspectives in all aspects of life. In health, a new discipline, Nanomedicine, was created to exploit the exciting new properties of nanomaterials: they were able to cross biological membranes, target specific cells, transport drugs, or even do drug-free therapy by being able to heat up or to generate reactive oxygen species when activated by the suitable electromagnetic radiation. A myriad of nanostructured systems was designed and built in the laboratory to channel these functionalities, and different families of nanoparticles emerged with previously unseen capabilities. The obvious question is: Why of all of these promising nanoparticle systems only a handful have reached clinical trials and even fewer have succeeded? In my view, the success of Nanomedicine has been restricted due to three main challenges: First, nanomaterials must be able to perform effectively under the conditions prevailing in the target environment, which may be very different from those used in the laboratory as a proof of concept. Second, the nanoparticle must be delivered selectively (or at least preferentially) to the target. This is also a formidable challenge. For instance, in oncology, current methods that rely on the EPR effect or even targeted delivery, present very low delivery efficiency, and this has given rise to a variety of alternative delivery methods. Third, ideally the nanoparticle should be activated only at the target site, to avoid side effects in healthy cells. For this, a variety of possibilities exist such as electromagnetic field-based activation, environment-related activation, and so on. The talk will present an overview of the area, identifying roadblocks and some possible solutions. Recent advances regarding each of the above areas will be critically discussed