UV irradiation significantly alters nanoplastics (NPs) physicochemical properties, thus affecting their biological toxicity. This study is the first to assess the influence of virgin and UV-aged polystyrene NPs (v-PS NPs, a-PS NPs) on the intestinal barrier of ICR mice. We found that a-PS NPs can cause more severe intestinal barrier damage compared with v-PS NPs. The reason may be attributed to that a-PS NPs produced more ROS in intestinal tissue. Moreover, the strong oxidizing property of hydroxyl radicals (·OH) generated from the a-PS NPs can damage cell membranes through lipid peroxidation, thereby leading to a low clearance rate of ·OH due to the impaired intestinal tissue function, in turn, causing more ROS to accumulate and inducing severe oxidative damage. This research underscores the crucial role of ·OH in mediating oxidative damage from UV-aged nanoparticles, emphasizing the need to consider environmental factors in assessing NPs toxicity.

中文翻译：

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紫外线老化的聚苯乙烯纳米塑料因活性氧过量产生而加重肠道屏障损伤


紫外线照射会显着改变纳米塑料（NP）的理化性质，从而影响其生物毒性。这项研究首次评估了原始和紫外线老化的聚苯乙烯纳米颗粒（v-PS NP、a-PS NP）对 ICR 小鼠肠道屏障的影响。我们发现，与 v-PS NP 相比，a-PS NP 会造成更严重的肠道屏障损伤。原因可能是由于a-PS NPs在肠道组织中产生了更多的ROS。此外，a-PS NPs产生的羟基自由基（·OH）具有强氧化性，可通过脂质过氧化损伤细胞膜，从而导致肠道组织功能受损，导致·OH清除率低，进而导致肠道菌群失调。更多的活性氧积累并诱导严重的氧化损伤。这项研究强调了·OH 在介导紫外线老化纳米颗粒氧化损伤中的关键作用，强调在评估纳米颗粒毒性时需要考虑环境因素。