The chromatograms of BPA 5 mg/L + TiO2 10 mg/L before and after mixture exposure are shown in Figure 2C, D. This experiment primarily demonstrated that an adsorption relationship between BPA and TiO2-NPs did exist. Adsorption kinetics of BPA on TiO2-NPs Adsorption kinetics was observed for 3 h and the results are presented in Figure 3. The initial concentration of BPA and TiO2-NPs was 5 and 10 mg/L, respectively. The adsorption process of BPA onto TiO2-NPs

was fast. After the adsorption began, the adsorption percentage of BPA on TiO2-NPs increased rapidly and the percentage reached 40% approximately at 5 min. The maximal amount of BPA adsorbed by TiO2-NPs appeared at 30 min, and the value was approximately 70%. The adsorption reached equilibrium basically after 60 min. Figure 3 Adsorption kinetics of BPA on TiO 2 -NPs. The effect of TiO2-NPs alone on zebrafish embryos In this study, significant morphological Selleckchem ATM inhibitor selleck inhibitor abnormalities were not observed in the zebrafish embryos, when exposed to TiO2-NPs suspensions of different concentrations. The 96-h survival rate of the embryos decreased slightly when exposed

to 40 mg/L TiO2-NPs, but there was no significant difference between the treatment and control groups. However, TiO2-NPs were observed to accumulate on the surface of the exposed egg envelopes (Figure 4G, H, J). With increasing concentrations, more TiO2-NPs adhered to and aggregated on the surface of the egg envelopes. When the concentration was increased to 40 mg/L, the egg envelope surface became turbid and difficult to be observed. Figure 4 Effect of TiO 2 -NPs alone and combined toxicological effects of TiO 2 -NPs and BPA on zebrafish embryos. (A-D, I, K) Normal embryonic development of zebrafish. (E, F, I-N) Observed abnormalities (arrows). (G, H, J) TiO2-NPs accumulation (arrows) on the surface of the exposed egg envelopes. Scale bar, 385 μm in (A) to (H) and 1,050 μm

in (I) to (N). Additionally, the hatching rate of the zebrafish embryos was influenced by TiO2-NPs exposure (Figure 5). Compared with treatment groups at lower concentrations and the control group, the hatching rate at 72 hpf of the embryos that were exposed to 40 mg/L of TiO2-NPs was significantly Carnitine palmitoyltransferase II less (p < 0.05). Figure 5 Hatching rate of the zebrafish embryos. *Significant difference compared to other groups (one-way ANOVA, p < 0.05). The combined toxicological effects of TiO2-NPs and BPA on zebrafish embryos: embryo survival, morphological abnormalities, and hatching rate No effect was observed in the zebrafish embryos of the dilution solvent control group (data not shown). No dead embryos were observed in the dilution water control group. There were no significant differences between the BPA alone-exposed and mixture-exposed groups with BPA at 0.5, 1, and 2 mg/L.