Molecular Dynamics Simulations of the Silica-Cell Membrane Interaction: Insights on Biomineralization and Nanotoxicity
Molecular Dynamics Simulations of the Silica-Cell Membrane Interaction: Insights on Biomineralization and Nanotoxicity
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DOI：
10.1021/acs.jpcc.8b04537
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发表时间：
2018-09-20
影响因子：
3.7
通讯作者：
Ciacchi, Lucio Colombi
中科院分区：
文献类型：
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作者：
Delle Piane, Massimo;Potthoff, Sebastian;Ciacchi, Lucio Colombi
二氧化硅(SiO_2)与生物体系的相互作用是复杂而矛盾的。一方面，二氧化硅是几种生物矿化过程的基础(例如，在海绵中)。另一方面，二氧化硅纳米颗粒和粉尘可能会导致矽肺，并在细胞水平上导致溶血。这些毒性反应强烈依赖于二氧化硅多晶型，其根本原因仍在争论中。二氧化硅生物矿化和二氧化硅诱导的纳米毒性都可能与细胞膜和二氧化硅颗粒表面的分子识别机制相似。在这一假设的基础上，我们利用经典的分子动力学模拟，结合先进的采样技术，获得了不同类型的二氧化硅纳米颗粒与红细胞膜之间相互作用的原子图。我们预测的与膜交叉相关的自由能分布没有证据表明纳米颗粒在膜/水界面上的分离，无论它们的硅核性、结构和电荷如何。然而，相关的分子轨迹暗示了一种可能的直接移位机制，在这种机制中，二氧化硅纳米团簇对膜的动力学和稳定性产生了局部和大规模的影响。这为基于纳米颗粒诱导的膜穿孔的二氧化硅纳米毒性的可能途径提供了线索。
The interaction of silica (SiO2) with biological systems is complex and contradictory. On the one hand, silica is at the basis of several biomineralization processes (e.g., in sponges). On the other hand, silica nanoparticles and dust may lead to silicosis and, at the cellular level, hemolysis. These toxic responses are strongly dependent on the silica polymorph and their root causes are still under debate. Both silica biomineralization and silica-induced nanotoxicity could be related to similar mechanisms of molecular recognition between the cellular membranes and the surface of the SiO2 particles. On the basis of this hypothesis, we employed classical molecular dynamics simulations, coupled to advanced sampling techniques, to achieve an atomistic picture of the interactions between different types of silica nanoparticles and the membrane of erythrocytes. Our predicted free-energy profiles associated with membrane crossing give no evidence for segregation of nanoparticles at the membrane/water interface, irrespective of their Si nuclearity, structure, and charge. The associated molecular trajectories, however, are suggestive of a possible direct translocation mechanism, in which silica nanoclusters elicit both local and large-scale effects on the membrane dynamics and stability. This gives hints on possible pathways for silica nanotoxicity based on nanoparticle-induced membrane perforation.