PDF(Pubmed)
Abstract：
Popularized on social media, hand-moldable plastics are formed by consumers into tools, trinkets, and dental prosthetics. Despite the anticipated dermal and oral contact, manufacturers share little information with consumers about these materials, which are typically sold as microplastic-sized resin pellets. Inherent to their function, moldable plastics pose a risk of dermal and oral exposure to unknown leachable substances. We analyzed 12 moldable plastics advertised for modeling and dental applications and determined them to be polycaprolactone (PCL) or thermoplastic polyurethane (TPU). The bioactivities of the most popular brands advertised for modeling applications of each type of polymer were evaluated using a zebrafish embryo bioassay. While water-borne exposure to the TPU pellets did not affect the targeted developmental end points at any concentration tested, the PCL pellets were acutely toxic above 1 pellet/mL. The aqueous leachates of the PCL pellets demonstrated similar toxicity. Methanolic extracts from the PCL pellets were assayed for their bioactivity using the Attagene FACTORIAL platform. Of the 69 measured end points, the extracts activated nuclear receptors and transcription factors for xenobiotic metabolism (pregnane X receptor, PXR), lipid metabolism (peroxisome proliferator-activated receptor γ, PPARγ), and oxidative stress (nuclear factor erythroid 2-related factor 2, NRF2). By nontargeted high-resolution comprehensive two-dimensional gas chromatography (GC × GC-HRT), we tentatively identified several compounds in the methanolic extracts, including PCL oligomers, a phenolic antioxidant, and residues of suspected antihydrolysis and cross-linking additives. In a follow-up zebrafish embryo bioassay, because of its stated high purity, biomedical grade PCL was tested to mitigate any confounding effects due to chemical additives in the PCL pellets; it elicited comparable acute toxicity. From these orthogonal and complementary experiments, we suggest that the toxicity was due to oligomers and nanoplastics released from the PCL rather than chemical additives. These results challenge the perceived and assumed inertness of plastics and highlight their multiple sources of toxicity.
摘要：
在社交媒体上普及，手塑塑料由消费者制成工具，小饰品,和牙科修复术。尽管预期皮肤和口腔接触，制造商很少与消费者分享关于这些材料的信息，它们通常作为微塑料大小的树脂颗粒出售。它们固有的功能，可塑塑料存在皮肤和口腔暴露于未知可浸出物质的风险。我们分析了12种用于建模和牙科应用的可模制塑料，并确定它们是聚己内酯（PCL）或热塑性聚氨酯（TPU）。使用斑马鱼胚胎生物测定法评估了为每种聚合物建模应用而宣传的最受欢迎品牌的生物活性。虽然在任何测试浓度下，水性暴露于TPU颗粒不会影响目标发育终点，PCL颗粒在1颗粒/mL以上有剧毒。PCL颗粒的含水浸出液表现出相似的毒性。使用AttageneFACTORIAL平台测定来自PCL颗粒的甲醇提取物的生物活性。在69个测量的终点中，提取物激活的核受体和转录因子用于异种生物代谢(孕烷X受体，PXR),脂质代谢(过氧化物酶体增殖物激活受体γ，PPARγ),和氧化应激（核因子红系2相关因子2，NRF2）。通过非靶向高分辨率全面二维气相色谱（GC×GC-HRT），我们初步确定了甲醇提取物中的几种化合物，包括PCL低聚物，一种酚类抗氧化剂,以及可疑的抗水解和交联添加剂的残留物。在后续的斑马鱼胚胎生物测定中，由于其陈述的高纯度，对生物医学级PCL进行了测试，以减轻由于PCL颗粒中的化学添加剂引起的任何混杂效应；它引起了可比的急性毒性。从这些正交和互补实验中，我们认为毒性是由于从PCL释放的低聚物和纳米塑料而不是化学添加剂。这些结果挑战了塑料的感知和假定的惰性，并突出了它们的多种毒性来源。
