7. Toxicity of Nanodrug Delivery Systems

The study of the potential toxicity of NPs is essential for the safe development of these vehicles. The lack of strategies, regulatory requirements, and validated protocols, along with the particular physical, chemical and biological properties of these materials, makes the evaluation of the preclinical toxicity very complex. Taking into consideration the outcomes of the toxicological investigations reviewed here, it seems that the toxicity of these nanocarriers is quite low. Most of the in vivo toxicological investigations did not demonstrate effects at very high doses whereas in vitro studies showed some toxic effects. However, more in vitro and in vivo toxicity assessments are required to reach a apparent conclusion about the potential toxic effect of these nanocarriers; the progress of validated protocols and the performance of chronic studies are of immense importance.