Micro- and nanoplastics (MNPs) represent one of the most widespread environmental pollutants of the twenty-first century to which all humans are orally exposed. Upon ingestion, MNPs pass harsh biochemical conditions within the gastrointestinal tract, causing a unique protein corona on the MNP surface. Little is known about the digestion-associated protein corona and its impact on the cellular uptake of MNPs. Here, we systematically studied the influence of gastrointestinal digestion on the cellular uptake of neutral and charged polystyrene MNPs using THP-1-derived macrophages. The protein corona composition was quantified using LC‒MS–MS-based proteomics, and the cellular uptake of MNPs was determined using flow cytometry and confocal microscopy. Gastrointestinal digestion resulted in a distinct protein corona on MNPs that was retained in serum-containing cell culture medium. Digestion increased the uptake of uncharged MNPs below 500 nm by 4.0–6.1-fold but did not affect the uptake of larger sized or charged MNPs. Forty proteins showed a good correlation between protein abundance and MNP uptake, including coagulation factors, apolipoproteins and vitronectin. This study provides quantitative data on the presence of gastrointestinal proteins on MNPs and relates this to cellular uptake, underpinning the need to include the protein corona in hazard assessment of MNPs.

中文翻译：

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聚苯乙烯纳米和微塑料的体外胃肠道消化相关蛋白冠增加了人类 THP-1 衍生巨噬细胞的摄取

微塑料和纳米塑料 (MNP) 是二十一世纪最广泛的环境污染物之一，所有人类都通过口腔接触到它。摄入后，MNP 在胃肠道内通过严酷的生化条件，在 MNP 表面形成独特的蛋白冠。关于消化相关蛋白冠及其对 MNP 细胞摄取的影响知之甚少。在这里，我们使用 THP-1 衍生的巨噬细胞系统地研究了胃肠道消化对中性和带电聚苯乙烯 MNP 的细胞摄取的影响。使用基于 LC-MS-MS 的蛋白质组学对蛋白质冠组成进行定量，并使用流式细胞术和共聚焦显微镜测定 MNP 的细胞摄取。胃肠道消化导致 MNP 上形成独特的蛋白冠，该蛋白冠保留在含血清的细胞培养基中。消化使 500 nm 以下不带电 MNP 的摄取增加了 4.0-6.1 倍，但不影响较大尺寸或带电 MNP 的摄取。四十种蛋白质在蛋白质丰度和 MNP 摄取之间显示出良好的相关性，包括凝血因子、载脂蛋白和玻连蛋白。这项研究提供了 MNP 上胃肠道蛋白存在的定量数据，并将其与细胞摄取联系起来，支持将蛋白冠纳入 MNP 危害评估的必要性。