Aluminium oxide nanoparticles (Al2O3 NPs) potentially cause health hazards after their release into the environment. The crystalline phase of Al2O3 NPs determines their surface structure and the number of functional groups. The adsorption of natural organic matter (NOM) or biomolecules on the surface Al2O3 NPs also alters their surface properties and subsequent interactions with organisms. In this study, the roles of the Al2O3 crystalline phase and the surface coating of the nanoparticles on the membrane integrity and fluidity were investigated. Giant and small unilamellar vesicles (GUVs and SUVs) were prepared as model cell membranes to detect membrane disruption after exposure to Al2O3 NPs. Due to amorphous structure and high surface activity of γ-Al2O3 NPs, they had a stronger affinity with the membrane and caused more serious membrane rupture than that of α-Al2O3 NPs. The deposition of Al2O3 NPs on the membrane and the induced membrane disruption were monitored by a quartz crystal microbalance with dissipation (QCM-D) method. HA-coated Al2O3 NPs disrupted the SUV layer on the QCM-D sensor, while BSA-coated Al2O3 NPs only adhered to the membrane and induced unremarkable vesicle disruption. In addition, untreated γ-Al2O3 NPs induced remarkable gelation of a negatively charged membrane, but other types of Al2O3 NPs caused negligible membrane phase changes. The outcomes of this study demonstrate that the crystalline phase of the Al2O3 NPs affects the integrity and fluidity of cell membranes. The protein coatings on the NPs weaken the NP-membrane interaction, while HA coatings increase the damage of the NP-induced interaction.

中文翻译：

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Al2O3纳米颗粒的结晶相和表面涂层及其对模型细胞膜完整性和流动性的影响。

氧化铝纳米粒子（Al2O3 NPs）释放到环境中后可能对健康造成危害。Al2O3 NP的晶相决定了它们的表面结构和官能团的数量。天然有机物（NOM）或生物分子在表面Al2O3 NP上的吸附也会改变其表面性质以及随后与生物的相互作用。在这项研究中，研究了Al2O3结晶相和纳米颗粒表面涂层对膜完整性和流动性的作用。制备了巨大的单层小囊泡（GUV和SUV）作为模型细胞膜，以检测暴露于Al2O3 NP后的膜破裂。由于γ-Al2O3NP的非晶结构和高表面活性，与α-Al2O3NPs相比，它们与膜的亲和力更强，并引起更严重的膜破裂。Al2O3 NPs在膜上的沉积和诱导的膜破裂通过带耗散的石英晶体微天平（QCM-D）方法进行监测。HA涂层的Al2O3 NP破坏了QCM-D传感器上的SUV层，而BSA涂层的Al2O3 NP仅粘附在膜上，并引起了明显的囊泡破坏。此外，未经处理的γ-Al2O3NPs引起带负电的膜明显凝胶化，但其他类型的Al2O3 NPs引起的膜相变可忽略不计。这项研究的结果表明，Al2O3 NP的结晶相会影响细胞膜的完整性和流动性。NP上的蛋白质涂层会削弱NP膜的相互作用，