Toxicity of 50-nm polystyrene particles co-administered to mice with acetaminophen, 5-aminosalicylic acid or tetracycline.

We investigated whether nano-sized polystyrene particles affect drug-induced toxicity. The particles, which are widely used industrially, had diameters of 50 (NPP50), 200 (NPP200) or 1000 (NPP1000) nm. The toxic chemicals tested were acetaminophen (APAP), 5-aminosalicylic acid (5-ASA), tetracycline (TC), and sodium valproate (VPA). All treatments in the absence of the nanoparticles were non-lethal and did not result in severe toxicity. However, when mice were injected with APAP, 5-ASA or TC together with polystyrene particles, synergistic, enhanced toxicity was observed in mice injected with NPP50. These synergic effects were not observed in mice co-injected with NPP200 or NPP1000. On the other hand, co-administration of VPA and NPP50, NPP200 or NPP1000 did not elevate toxicity. The results show that NPP50 differs in hepatotoxicity depending on the drug co-administered. These findings suggest that further evaluation of the interactions between polystyrene nanoparticles and drugs is a critical prerequisite to the pharmaceutical application of nanotechnology.