The increased environmental presence of micro-/nanoplastics (MNPLs) and the potential health risks associated with their exposure classify them as environmental pollutants with special environmental and health concerns. Consequently, there is an urgent need to investigate the potential risks associated with secondary MNPLs. In this context, using “true-to-life” MNPLs, resulting from the laboratory degradation of plastic goods, may be a sound approach. These non-commercial secondary MNPLs must be labeled to track their presence/journeys inside cells or organisms. Because the cell internalization of MNPLs is commonly analyzed using fluorescence techniques, the use of fluorescent dyes may be a sound method to label them. Five different compounds comprising two chemical dyes (Nile Red and Rhodamine-B), one optical brightener (Opticol), and two industrial dyes (Amarillo Luminoso and iDye PolyPink) were tested to determine their potential for such applications. Using commercial standards of polystyrene nanoplastics (PSNPLs) with an average size of 170 nm, different characteristics of the selected dyes such as the absence of impact on cell viability, specificity for plastic staining, no leaching, and lack of interference with other fluorochromes were analyzed. Based on the overall data obtained in the wide battery of assays performed, iDye PolyPink exhibited the most advantages, with respect to the other compounds, and was selected to effectively label “true-to-life” MNPLs. These advantages were confirmed using a proposed protocol, and labeling titanium-doped PETNPLs (obtained from the degradation of milk PET plastic bottles), as an example of “true-to-life” secondary NPLs. These results confirmed the usefulness of iDye PolyPink for labeling MNPLs and detecting cell internalization.

中文翻译：

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用于生物应用的微/纳米塑料荧光标记，重点是“逼真”跟踪


微/纳米塑料（MNPL）在环境中的存在量不断增加，以及与其接触相关的潜在健康风险，将其归类为具有特殊环境和健康问题的环境污染物。因此，迫切需要调查与次要 MNPL 相关的潜在风险。在这种情况下，使用由塑料制品实验室降解产生的“逼真”MNPL 可能是一种合理的方法。这些非商业性二级 MNPL 必须进行标记，以追踪它们在细胞或生物体中的存在/旅程。由于 MNPL 的细胞内化通常使用荧光技术进行分析，因此使用荧光染料可能是标记它们的合理方法。测试了五种不同的化合物，包括两种化学染料（尼罗红和罗丹明-B）、一种荧光增白剂（Opticol）和两种工业染料（Amarillo Luminoso 和 iDye PolyPink），以确定它们在此类应用中的潜力。使用平均尺寸为 170 nm 的聚苯乙烯纳米塑料 (PSNPL) 商业标准，分析了所选染料的不同特性，例如对细胞活力不产生影响、塑料染色的特异性、无浸出以及不与其他荧光染料干扰。根据在进行的广泛测定中获得的总体数据，iDye PolyPink 相对于其他化合物表现出最大的优势，并被选择用于有效标记“真实”的 MNPL。使用拟议的方案和标记掺钛 PETNPL（从牛奶 PET 塑料瓶的降解中获得）作为“真实”二级不良贷款的示例，证实了这些优点。 这些结果证实了 iDye PolyPink 在标记 MNPL 和检测细胞内化方面的有用性。