In vitro cytotoxicity and antibiotic application of green route surface modified ferromagnetic TiO 2 nanoparticles

The enormous numbers of applications of TiO 2 nanoparticles (NPs) cause concern about their risk to the environment and human health. Consequently, motivated by the necessity of searching for new sources of TiO 2 NPs of low cytotoxicity with antibacterial activity, we synthesized TiO 2 NPs by a green route using a solution of titanium(iv) isopropoxide as a precursor and an aqueous extract of Artocarpus heterophyllus leaf as a reducing and surface modifying agent. We investigated their structure, shape, size, and magnetic properties, and evaluated their antibiotic application and cytotoxicity. The synthesized TiO 2 NPs were applied against two Gram-negative bacteria (E. coli and S. typhimurium) and two Gram-positive bacteria (S. aureus and B. subtilis) to observe their antibacterial activity; and eventually clear zones of inhibition formed by the TiO 2 NPs were obtained. Moreover, after exposing the synthesized TiO 2 NPs to HeLa cells (carcinoma cells) and Vero cells (normal cells), no toxic effect was found up to a dose of 1000 mg L -1 , indicating the safe use of the samples up to at least 1000 mg L -1 . However, toxic effects on HeLa cells and Vero cells were observed at doses of 2000 mg L -1 and 3000 mg L -1 , respectively. These results indicate the safe use of Artocarpus heterophyllus leaf extract mediated synthesized TiO 2 NPs in their potential applications. © 2019 The Royal Society of Chemistry