Nanoparticle Interaction with Biomolecules: How it Shapes the Nano-Effects on Immunity

The different modes in which small and large molecules can be associated to a nanoparticle surface, either covalently or loosely linked, in an ordered or disordered fashion, and with mixtures of other molecules, play a determining role in the nature of the interactions between nano-objects and the immune system. The immune system may detect or not detect the nanoparticles, and tolerate them or initiate a defensive response, due to the nanoparticles themselves, to bystanders, sometime pollutants, or secondary effects, as those induced by the corrosion of the nanoparticle and the concomitant release of cations. In vitro, this can be translated in the acquisition of effector functions, such as the synthesis of cytokines, or in a lack of effect, if the NPs pass undetected.