Centre for Nanobiotechnology, Vellore Institute of Technology (VIT), Vellore 632014, India.
Centre for Nanobiotechnology, Vellore Institute of Technology (VIT), Vellore 632014, India.
Aquat Toxicol. 2019 Feb;207:208-216. doi: 10.1016/j.aquatox.2018.12.014. Epub 2018 Dec 18.
Increased utilization of titanium dioxide nanoparticles (TiO NPs) for commercial as well as industrial purposes resulted in the accumulation of nanoparticles in the marine system. Microplastics being an emerging secondary pollutant in the marine ecosystem have an impact on the toxic effects of TiO NPs which has not been evaluated up to date. So it is important to assess the toxic effects of both these pollutants on the marine environment. The present study examines the impact of differently functionalized microplastics on the toxic effects of P25 TiO NPs to marine algae Chlorella sp. The tendency of nanoparticles to undergo aggregation in artificial seawater was observed with increase in time. The median effective concentration for TiO NPs was found to be 81 μM which indicates higher toxic effects of NPs toward algae. In contrast, microplastics irrespective of their difference in functionalization had minimal toxic effect of about 15% at their higher concentration tested, 1000 mg L. Plain and aminated polystyrene microplastics enhanced the TiO NPs toxicity which was further validated with oxidative stress determination studies like reactive oxygen species and lipid peroxidation assays. Negatively charged carboxylated polystyrene microplastics decreased the TiO NPs toxicity with possible hetero-aggregation between TiO NPs and microplastics in the system. The toxicity data obtained for the mixture was further corroborated with Abbott's mathematical model.
由于商业和工业用途对二氧化钛纳米粒子（TiO NPs）的需求增加，导致纳米粒子在海洋系统中积累。微塑料作为海洋生态系统中新兴的次生污染物，对 TiO NPs 的毒性影响尚未得到评估。因此，评估这两种污染物对海洋环境的毒性影响非常重要。本研究考察了不同功能化微塑料对海洋藻类小球藻 TiO NPs 毒性的影响。研究观察到，随着时间的推移，纳米颗粒在人工海水中有团聚的趋势。发现 TiO NPs 的中效浓度为 81 μM，这表明纳米颗粒对藻类的毒性更高。相比之下，微塑料无论其功能化差异如何，在测试的较高浓度下，毒性作用最小，约为 15%，浓度为 1000 mg/L。普通和胺化聚苯乙烯微塑料增强了 TiO NPs 的毒性，这通过活性氧和脂质过氧化测定等氧化应激确定研究得到了进一步验证。带负电荷的羧化聚苯乙烯微塑料降低了 TiO NPs 的毒性，这可能是由于系统中 TiO NPs 和微塑料之间存在异质聚集。混合物的毒性数据进一步得到了 Abbott 数学模型的证实。
