Smart Materials , Istituto Italiano di Tecnologia , Via Morego, 30 , 16163 Genova , Italy.
Department of Informatics, Bioengineering, Robotics and Systems Engineering , University of Genova , Via All'Opera Pia, 13 , 16145 Genova , Italy.
ACS Nano. 2018 Aug 28;12(8):7690-7700. doi: 10.1021/acsnano.8b01331. Epub 2018 Jun 26.
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.
微塑料和纳米塑料存在于海洋环境中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，由于缺乏从水系中收集纳米塑料的适当方法，因此需要使用工程模型纳米颗粒来探索它们与生物系统的相互作用，但这些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来形成聚对苯二甲酸乙二醇酯（PET）纳米塑料，这些纳米塑料模拟了真实的环境纳米污染物，与通过胶体化学获得的合成样品不同。对 PET 纳米塑料的化学/物理性质和在不同介质中的稳定性进行了仔细的表征。纳米塑料的平均尺寸约为 100nm，具有显著的尺寸和形状异质性，并且其表面存在弱酸性基团，与光降解的 PET 塑料相似。尽管体外研究对人 Caco-2 肠上皮细胞没有显示出毒性作用，但形成的纳米塑料在内涵体中大量内化，在模拟溶酶体环境中表现出细胞内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 显示出很高的穿过肠道屏障的倾向，对健康具有不可预测的长期影响，并可能通过纳米污染物介导的分散化学物质的运输。
