Approaching a unified theory for particle-induced inflammation

Particles such as silica, asbestos, and engineered nanomaterials (ENM) that fall within a relatively small size range (<100 nm in at least one dimension) are known to have serious health consequences following exposure. Studies aimed at determining the mechanisms of toxicity for environmental particles have been ongoing for decades. However, the recent explosion of ENM into the market has resulted in the emergence of many recent studies aimed at determining the mechanisms underlying the pathologies associated with certain forms of ENM. In this chapter, we propose that many of the principles that have guided the toxicity studies of environmental particles may also apply to bioactive ENM. In fact, the initiating event for all downstream pathologies caused by exposure to both bioactive ENM and environmental particles appears to be lysosomal membrane permeabilization (LMP). Therefore, focusing on LMP as the "unifying" principle for particle toxicity studies may allow the field to advance at an increased pace.