Today, cosmetic products are very popular with both men and women to improve their appearance and increase their social acceptability. In this study, nano-sized (30–300 nm) plastic particles were isolated from the commercial face-scrubs and treated on the human keratinocytes. The observed adherence of polyethylene nano-plastics (PENPs), polystyrene NPs (PSNPs), and face-scrubs isolated nano-plastics (NPs) on the keratin layer reveals a significant attachment of NPs from the cosmetics that are applied on the skin for a short duration. This attachment property could facilitate further adherence of protein molecules on NPs and the protein-corona formation. The protein-corona mimics protein aggregates, thereby triggers macropinocytosis, followed by the macropinolysosomal process in the cell. These internalized NPs induced the concentration-dependent cytotoxic, cytostatic and cytoprotective activity in keratinocytes. Both single dose and chronic long-term exposure of lethal and sub-lethal concentrations of NPs resulted in oxidative stress-mediated down-regulation of cell growth and proliferation inhibition. Autophagic structures and premature aging were also observed using an electron microscopy and a senescence marker, respectively in the NPs internalized HaCaT cells incubated in a fresh, NPs-free medium. Though 2D culture models have many limitations, it produces significant conceptual advancements. This work provides an insight into the NPs concentration-dependent regulatory, cytoprotective, and cytotoxic effects in HaCaT cells. However, 3D model studies are required to identify the detailed mechanisms of NPs toxicity and cytoprotective events in cells at the molecular level.

中文翻译：

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纳米塑料颗粒内化和诱导人角质形成细胞反应的前景

今天，化妆品非常受男性和女性的欢迎，以改善他们的外表并增加他们的社会接受度。在这项研究中，纳米级（30-300 nm）塑料颗粒从商业面部磨砂膏中分离出来，并在人类角质形成细胞上进行处理。观察到的聚乙烯纳米塑料 (PENPs)、聚苯乙烯 NPs (PSNPs) 和面部磨砂分离的纳米塑料 (NPs) 在角蛋白层上的粘附揭示了化妆品中 NPs 的显着附着，这些化妆品涂抹在皮肤上持续时间短。这种附着特性可以促进蛋白质分子在 NPs 上的进一步粘附和蛋白质电晕的形成。蛋白质电晕模拟蛋白质聚集体，从而触发巨胞饮作用，然后是细胞中的巨胞饮溶酶体过程。这些内化的 NPs 在角质形成细胞中诱导浓度依赖性的细胞毒性、细胞生长抑制和细胞保护活性。单剂量和慢性长期暴露于致死和亚致死浓度的 NPs 都会导致氧化应激介导的细胞生长和增殖抑制的下调。还使用电子显微镜和衰老标记分别观察了自噬结构和过早衰老，分别在无纳米颗粒的新鲜培养基中孵育的纳米颗粒内化 HaCaT 细胞中。尽管 2D 文化模型有许多局限性，但它产生了重大的概念进步。这项工作提供了对 HaCaT 细胞中 NPs 浓度依赖性调节、细胞保护和细胞毒性作用的深入了解。然而，