Behaviors and Persistence of Nanomaterials in Biomedical Applications

Chapter 6Avoiding the Persistence of Metal Nanomaterials

In the previous chapters, the physio-chemical properties of nanomaterials have been summarized (chapter 2) and their promising applications as therapeutic and diagnostic discussed (chapter 3). In chapter 4 we have comprehensively reviewed the interactions between nanomaterials and biological entities, discussing a number of issues (immune response, short blood circulation half-life, persistence in the organism) that have prevented the clinical translation of the majority of promising nanomaterials. Indeed, in chapter 5 we have overviewed the current status of nanomaterials translated to clinics, highlighting the impressive percentage of promising nanomaterials that have failed the translation to the market. In particular, most of the promising inorganic nanomaterials that have been engineered for oncology are still confined to the bench side. Noteworthy, none of the proposed noble metal-based nanomaterials have yet obtained clinical approval from FDA or EMA. It is worth to remember here that one of the key-question for FDA or EMA approbation of a novel nanomaterial is whether all of its components are completely cleared and in which time-frame; leaving residues in patients is not acceptable. Likely, the main hurdle that hampers the clinical translation of noble metals nanomaterials is related to the dilemma concerning their optimal size. Usually, noble metal NPs proposed for theranostics have a diameter over 20 nm. This ...