Nanoclays and graphene oxide nanomaterials represent a class of materials sharing similar shapes constituted of high aspect ratio platelets. The increased production of these materials for various industrial applications increases the risk of occupational exposure, consequently with elevated risk of adverse reactions and development of pulmonary diseases, including lung cancer. In this study, pro-inflammatory responses and genotoxicity were assessed in alveolar epithelial cells (A549) and activated THP-1 macrophages (THP-1a) after exposure to three nanoclays; a pristine (Bentonite) and two surface modified (benzalkonium chloride-coated Nanofil9, and dialkyldimethyl-ammonium-coated NanofilSE3000); graphene oxide (GO) and reduced graphene oxide (r-GO) nanomaterials. The pro-inflammatory response in terms of IL-8 expression was strongest in cells exposed to Bentonite, whereas surface modification resulted in decreased toxicity in both cell lines when exposed to Nanofil9 and NanofilSE3000. GO and r-GO induced a pro-inflammatory response in A549 cells, while no effect was detected with the two nanomaterials on THP-1a cells. The pro-inflammatory response was strongly correlated with in vivo inflammation in mice after intra-tracheal instillation when doses were normalized against surface area. Genotoxicity was assessed as DNA strand breaks, using the alkaline comet assay. In A549 cells, an increase in DNA strand breaks was detected only in cells exposed to Bentonite, whereas Bentonite, NanofilSE3000 and GO caused an increased level of genotoxicity in THP-1a cells. Genotoxicity in THP-1a cells was concordant with the DNA damage in bronchoalveolar lavage fluid cells following 1 and 3 days after intra-tracheal instillation in mice. In conclusion, this study shows that surface modification of pristine nanoclays reduces the inflammatory and genotoxic response in A549 and THP-1a cells, and these in vitro models show comparable toxicity to what seen in previous mouse studies with the same materials.

纳米粘土和氧化石墨烯纳米材料代表了一类具有相似形状的材料，由高纵横比薄片构成。用于各种工业应用的这些材料产量的增加增加了职业暴露的风险，因此增加了不良反应和肺部疾病（包括肺癌）发展的风险。在这项研究中，在暴露于三种纳米粘土后，评估了肺泡上皮细胞 (A549) 和活化的 THP-1 巨噬细胞 (THP-1a) 的促炎反应和遗传毒性；一个原始的（膨润土）和两个表面改性的（苯扎氯铵涂层的 Nanofil9 和二烷基二甲基铵涂层的 NanofilSE3000）；氧化石墨烯（GO）和还原氧化石墨烯（r-GO）纳米材料。就IL-8而言的促炎反应在暴露于膨润土的细胞中表达最强，而当暴露于 Nanofil9 和 NanofilSE3000 时，表面修饰导致两种细胞系的毒性降低。GO 和 r-GO 在 A549 细胞中诱导促炎反应，而这两种纳米材料未检测到对 THP-1a 细胞的影响。当剂量相对于表面积标准化时，促炎反应与气管内滴注后小鼠体内炎症密切相关。使用碱性彗星试验将遗传毒性评估为 DNA 链断裂。在 A549 细胞中，仅在暴露于膨润土的细胞中检测到 DNA 链断裂的增加，而膨润土、NanofilSE3000 和 GO 导致 THP-1a 细胞的基因毒性水平增加。THP-1a 细胞的基因毒性与小鼠气管内滴注后 1 天和 3 天后支气管肺泡灌洗液细胞中的 DNA 损伤一致。总之，这项研究表明，原始纳米粘土的表面改性降低了 A549 和 THP-1a 细胞的炎症和遗传毒性反应，并且这些体外模型显示出与以前使用相同材料进行的小鼠研究中所见的毒性相当。