Fabrication of TiO2/Zn2TiO4/Ag nanocomposite for synergic effects of UV radiation protection and antibacterial activity in sunscreen.Colloids Surf B Biointerfaces. 2020 Mar; 187:110652.CS
A systematic and detailed study has been designed and conducted, taking into account some of the proposed benefits such as increased efficiency, transparency, unique texture, protection of active ingredient and higher consumer compliance of cosmetics containing nano-sized metal oxides. The objective of the present study was to develop novel sunscreen cream containing a TiO2/Zn2TiO4/Ag nanocomposite for enhanced UV radiation protection and antibacterial activity. In this study, TiO2/Zn2TiO4/Ag nanocomposite was prepared using sol-gel method and characterized by FESEM, EDX, XRD, TGA, UV-vis spectrophotometry, and FTIR techniques. Different sunscreen creams were formulated by incorporating the nanocomposite and TiO2 nanoparticles and the Sun Protection Factor (SPF) against ultraviolet radiation and antibacterial activity were examined. The antibacterial activity of synthesized TiO2/Zn2TiO4/Ag nanocomposite was investigated against gram positive (S. aureus) and gram negative (Escherichia coli). TiO2/Zn2TiO4/Ag nanocomposite has a higher protective factor compared to TiO2 nanoparticles. The results show that the average particle sizes of the synthesized nanoparticles are on a scale below 100 nm. The energy gap of the TiO2/Zn2TiO4/Ag nanocomposite was 3.01 eV which is close to the energy gap of the pure TiO2 nanoparticles. The nanocomposite presents higher UV absorption than the pure TiO2 nanoparticles. According to MIC test, minimum inhibitory concentration for this nanocomposite was 10 mg/ml. According to the MTT test, up to 0.3 μg/ml of this nanocomposite was found not to be susceptible to toxicity and almost 79.5 % of the cells exposed to nanoparticles had vital activities. In fact, TiO2/Zn2TiO4/Ag nanocomposite addition to cream was considered, not only to achieve the best protection over the whole UV range but also to take advantage of any synergistic effects of them in sunscreens.
