Combined In vitro Effects of TiO2 Nanoparticles and Dimethyl Sulfoxide (DMSO) on HepG2 Hepatocytes

Abstract

Introduction: Professional workers that manufacture or use titanium dioxide (TiO 2 )-based paints are exposed to potentially toxic TiO 2 nanomaterials as well as to different paint solvents such as dimethyl sulfoxide (DMSO). In this context, we evaluate the combined cytotoxic effects of TiO 2 nanoparticles and DMSO on HepG 2 human hepatocytes.Methods: Three types of TiO 2 nanoparticles were used: commercial Degussa P25 and two samples synthesized by a hydrothermal procedure -undoped and Fe 3+ -doped TiO 2 . The effects of TiO 2 nanoparticles on HepG2 cells exposed to DMSO before, after or together with the TiO 2 treatment were investigated by viability and intracellular reactive oxygen species (ROS) determinations, performed using the MTT and DCFH-DA(2',7'-dichlorfluorescein-diacetate) methods respectively. Results:Results indicated that DMSO made HepG2 cells more susceptible to toxic effects induced by nanosized TiO 2 . In the absence of DMSO, none of the tested nanoparticles exhibited significant cytotoxic effects. Viability increases were detected after 48 hours of treatment and attributed to possible redox-sensitive proliferation mechanism striggered by the low and moderate amounts of produced ROS. The combined action of TiO 2 and DMSO led to a general viability decrease tendency. Significant effects (viability reductions and ROS generation) were observed in the case of cells first treated with Degussa P25 TiO 2 and afterwards exposed to DMSO. The hydrothermal materials exhibited reduced in vitro reactivity on HepG 2 hepatocytes. Conclusion:The study reveals the enhancement of nanosized TiO 2 toxicity induced by DMSO exposure, its findings having potential to help in the evaluation of professional health risks associated to the combined action of TiO 2 nanomaterials and paint solvents.

The Effects of Annealing Temperatures and Dimethylformamide Doses on Porous TiO2 Films

“…The dense TiO 2 film can be prepared by heating or annealing the porous characteristic under the proper temperature control, improving the disadvantages of porous TiO 2 film, such as low mechanical strength, low adhesive strength on the substrate, and the lower transmittance. On the other hand, among the solvents that were used, dimethyl sulfoxide (DMSO) was thought to be more useful due to its relatively less dangerous nature [27]. To improve transmittance, DMSO is commonly used as a formulation additive in the preparation of the TiO 2 electron transport layer (ETL) of perovskite solar cells [28].…”