In vitro cytotoxicity and antibiotic application of green route surface modified ferromagnetic TiO₂ nanoparticles

The enormous numbers of applications of TiO₂ nanoparticles (NPs) cause concern about their risk to the environment and human health. Consequently, motivated by the necessity of searching for new sources of TiO₂ NPs of low cytotoxicity with antibacterial activity, we synthesized TiO₂ 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 TiO₂ 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 TiO₂ NPs were obtained. Moreover, after exposing the synthesized TiO₂ 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 TiO₂ NPs in their potential applications.