Using experimental data of Escherichia coli to develop a QSAR model for predicting the photo-induced cytotoxicity of metal oxide nanoparticles.

A quantitative structure-activity relationship (QSAR) study of seventeen metal oxide nanoparticles (MNPs), in regard to their photo-induced toxicity to bacteria Escherichia coli, was developed by using quantum chemical methods. A simple and statistically significant QSAR model (F=33.83, R(2)=0.87) was successfully developed for the dark group based on two descriptors, absolute electronegativity of the metal and the metal oxide. Similarly, a best correlation (F=20.51, R(2)=0.804) was obtained to predict the photo-induced toxicity of MNPs by using two descriptors, molar heat capacity and average of the alpha and beta LUMO (lowest unoccupied molecular orbital) energies of the metal oxide. Revelation of these influential molecular descriptors may be useful in elucidating the mechanisms of nanotoxicity and for predicting the environmental risk associated with release of the MNPs. In addition, the developed model may have a role in the future design and manufacture of safe nanomaterials.