Nano-TiO2 removal using jellyfish extracts and an assessment of aquatic toxicity

Background Nano-TiO2 is a material used in various industries, and its usage is increasing every year. It is a concern that it is a potential ecotoxic substance because it flows into rivers after use. Since the material extracted from jellyfish as a biological material has the ability to capture nanomaterials, its possibility needs to be confirmed. Objective In this study, we used material extracted using the immune response of jellyfish (JEl) to capture N-TiO2 and confirm its capture ability and whether it has ecotoxicity. Results JEI bound to 61.94% of the total N- TiO2 administered after 0.5 h and maintained 73.29% of the binding capacity of N-TiO2 4 h after administration. The abnormality rate of the JEI-exposed group was 3.39 +/- 3.99%, which was not different from that of the control group, while the N-TiO2 exposure group showed an abnormality rate of 33.75 +/- 13.77%. The abnormality rate of N-TiO2 + JEI (11.36 +/- 8.10%) was 3 times lower than that of the N-TiO2 group. In the apoptosis test, the groups exposed to JEI and N-TiO2 + JEI showed significant decreases in fluorescence (9.11-fold and 7.62-fold, respectively), compared to the group exposed to N-TiO2 alone (P < 0.001). In the group exposed to N-TiO2, the transcript-level expression of stc2a, which is involved in cell homeostasis, was increased by more than twofold, whereas that of slc30a10, slc34a2b, slc31a1, ham, and pck1 was decreased by more than twofold. In contrast, the transcript-level expression of genes in the group exposed to N-TiO2 + JEI ranged from 0.320 to 1.194. Conclusion JEI not only captured N-TiO2 in a short period of time, but also showed no aquatic ecosystem toxicity and no genotoxicity.