Comparative in vitro cytotoxicity study of carbon nanotubes and titania nanostructures on human lung epithelial cells

► The in-vitro cytotoxic effects of CNTs and titania nanostructures were compared. ► The cytotoxicity was correlated with the physico-chemical properties of materials. ► CNTs were found to be relatively more toxic than titania nanostructures. ► Titania nanostructures were found to enhance cell proliferation.