The toxicity evaluation of inorganic nanoparticles has been increasingly reported, but toxicity studies concerned with biodegradable nanoparticles, especially the neurotoxicity evaluation, are still limited.For example, the potential neurotoxicity evaluation of Tween 80-modified chitosan nanoparticles (TmCS-NPs), one of the most widely used brain targeting vehicles, remains unknown.TmCS-NPs with a particles size of 240 nm were prepared by ionic cross-linking of chitosan with tripolyphosphate.