Planarians as an Alternative Standard Invertebrate Model to Assess the Eco-safety of Nanoparticles/Nanomaterials

With their ability to repair and/or regenerate any damaged or missing part of their body, freshwater planarians have gained more and more attention over the years for their potential application as bio-indicators of environmental and chemical stress. These free-living flatworms can be easily cultured under laboratory conditions, and they can be used to study regeneration, developmental biology, and behavior (feeding and locomotor activity) after exposure under strictly controlled conditions. In this chapter, after a general overview, we want to summarize some key factors that make them suitable for assessing the safety of emerging contaminants such as nanoparticles and nanomaterials. These substances, due to their peculiar and remarkable characteristics, are exponentially employed in many different fields of the production chain. So, it is fundamental to deeply investigate the biological mechanisms that occur after exposure, from molecular to population level, and freshwater planarians seem to be perfect to fulfill this goal.