Physico-chemical characteristics and cytogenotoxic potential of ZnO and TiO2 nanoparticles on human colon carcinoma cells

The aim of the present study is to investigate the role of the physicochemical properties of zinc oxide (ZnO) and titanium dioxide (TiO2) NPs in the potential cytotoxicity, genotoxicity and oxidative DNA damage induction on Caco-2 cell line. As a negative control, fine TiO2 particles were used. The characterisation of particles was carried out by electron microscopy (SEM, TEM) using a Soft Imaging System. To evaluate the effects of ZnO and TiO2 NPs induced on Caco-2 viability, Neutral Red assay was performed after treatment with different particle concentrations. The results showed a significant dose and time dependent effect after treatment with ZnO NPs. On the contrary, no effect was observed on Caco-2 cells exposed to TiO2 particles either in micro-size or in nano-size. The role of surface in the cytotoxicity induced on Caco-2 was also considered. The levels of DNA 8-oxodG, as the main marker of oxidative DNA damage, were measured by high-performance liquid chromatography with electrochemical detection (HPLC/EC). A significant increase in the 8-oxodG levels was observed after 6 h exposure for both NPs. The estimation of the potential genotoxicity of the two NPs is ongoing by the cytokinesis-block micronucleus assay. The authors concluded that the preliminary results showed that a slight micronucleus increase in binucleated cells was detected in the dose range applied only for ZnO.

Authors: Barone, F.; De Berardis, B.; Bizzarri, L.; Degan, P.; Andreoli, C.; Zijno, A.; De Angelis, I. ;Full Source: Journal of Physics: Conference Series 2011, 304, 012047/1-012047/7 (Eng) ;