Challenges of Biological Complexity in the Study of Nanotoxicology

The scale of nanoparticle use in consumer goods has grown exponentially over several decades owing to the unique properties of materials in this size range. At the same time, well-defined end of life cycle disposal strategies have not been developed for most materials, meaning that we are approaching the potential for a new ecological disaster with the release of millions of metric tons into the waste stream. The field of nanotoxicology has also expanded rapidly to investigate these potential hazards and has identified multiple mechanisms of toxicity to all tropes of life. While this research has been insightful, there are stipulations on how applicable many of these results are to real world applications. One of the major challenges in this research is that nanoparticles are immediately transformed when introduced into an environment. For example, biomolecules, such as proteins, rapidly coat nanoparticles with a shell, called a corona, that can modulate the toxicity of the core materials or aid the internalization into cells. This additional layer of complexity and the non-covalent nature of the corona has made it difficult to identify consistent trends in the study of nanotoxicity using traditional methods. In this perspective, we will highlight the limitations with current techniques, discuss advances that have been made to aid in these studies, and outline remaining challenges.