摘要

微生物和纳米塑料在海洋环境中的存在引起了人们的强烈关注，因为它们可能对人类健康产生负面影响。特别是，缺乏从水系统收集纳米塑料的适当方法强制使用工程模型纳米粒子来探索它们与生物系统的相互作用，结果不容易与实际情况相关联。在这项工作中，我们提出了一种可靠的自上而下的方法，基于聚合物的激光烧蚀，形成聚对苯二甲酸乙二醇酯（PET）纳米塑料，模仿真实的环境纳米污染物，不像通过胶体化学获得的合成样品。在化学/物理性质和不同介质中的稳定性方面仔细表征PET纳米颗粒。纳米塑料具有约。平均尺寸为100纳米，具有显着的尺寸和形状不均匀性，并且它们在其表面上呈现弱酸基团，类似于光降解的PET塑料。尽管体外研究对人Caco-2肠上皮细胞没有毒性作用，但形成的纳米塑料大部分内化于内溶酶体中，在模拟的溶酶体环境中显示出细胞内生物持久性和长期稳定性。有趣的是，当在肠上皮模型上进行测试时，纳米PET显示出穿过肠道屏障的高度倾向，对纳米污染物介导的分散化学物质的健康和潜在转运具有不可预测的长期影响。

The presence of micro- and nanoplastics in the marine environment is raising strong concerns since they can possibly have a negative impact on human health. In particular, the lack of appropriate methodologies to collect the nanoplastics from water systems imposes the use of engineered model nanoparticles to explore their interactions with biological systems, with results not easily correlated with the real case conditions. In this work, we propose a reliable top-down approach based on laser ablation of polymers to form polyethylene terephthalate (PET) nanoplastics, which mimic real environmental nanopollutants, unlike synthetic samples obtained by colloidal chemistry. PET nanoparticles were carefully characterized in terms of chemical/physical properties and stability in different media. The nanoplastics have a ca. 100 nm average dimension, with significant size and shape heterogeneity, and they present weak acid groups on their surface, similarly to photodegraded PET plastics. Despite no toxic effects emerging by in vitro studies on human Caco-2 intestinal epithelial cells, the formed nanoplastics were largely internalized in endolysosomes, showing intracellular biopersistence and long-term stability in a simulated lysosomal environment. Interestingly, when tested on a model of intestinal epithelium, nano-PET showed high propensity to cross the gut barrier, with unpredictable long-term effects on health and potential transport of dispersed chemicals mediated by the nanopollutants.

https://www.ncbi.nlm.nih.gov/pubmed/29944342