Preparation and characterization of titanium dioxide nanoparticles and in vitro investigation of their cytotoxicity and antibacterial activity against Staphylococcus aureus and Escherichia coli

Titanium dioxide nanoparticles (TiO2 NPs) are photo-active metallic nanoparticles becoming promising agents in modern biomedical applications. Herein, a novel process for the synthesis of TiO2 NPs with high stability was developed by a sol-gel process and to investigate their cytotoxicity and antibacterial activity. Numerous experiments have been performed to confirm the morphologies, compositions, and physicochemical properties of prepared TiO2 NPs, such as field emission scanning electron microscopy, dynamic light scattering, Zeta potential, Fourier transform infrared spectroscopy and X-ray diffraction. MTT assay was applied to assess the cytotoxicity of the prepared nanoparticles. The results indicate that the synthesized nanoparticles' diameter is about 68 nm and contains the anatase phase, in the range of 2 theta from 25 to 80 degrees C. The hydrodynamic radius of nanoparticles is about 140.4 nm, and the zeta potential of nanoparticles is about -44.6 mV. The MTT results have not shown any toxicity; the antibacterial inhibitory effect of TiO2 NPs at 200 mg/mL concentrations exhibited superior antibacterial activity at 15.9 +/- 0.1, 14.0 +/- 0.1 against Staphylococcus aureus and Escherichia coli, respectively. In conclusion, colloidal solutions with high stability were successfully synthesized, contributing to decreased dimensions and increased antibacterial properties.

Automated summary

A novel method for synthesizing stable titanium dioxide nanoparticles (TiO2 NPs) using a sol-gel process was developed and their cytotoxicity and antibacterial activity were investigated. The prepared TiO2 NPs were characterized by various techniques to confirm their morphologies, compositions, and physicochemical properties. The results showed that the synthesized nanoparticles had a diameter of approximately 68 nm and exhibited anatase phase. The nanoparticles also demonstrated high stability, with a hydrodynamic radius of about 140.4 nm and a zeta potential of -44.6 mV. MTT assay revealed no cytotoxicity, and the TiO2 NPs exhibited superior antibacterial activity against Staphylococcus aureus and Escherichia coli at a concentration of 200 mg/mL. In conclusion, the synthesized TiO2 NPs showed promising properties for biomedical applications, including decreased size and increased antibacterial activity.