School of Materials Science and Engineering, China University of Petroleum (East China), Qingdao 266580, China.
Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong, China.
Nanoscale. 2022 Apr 7;14(14):5384-5391. doi: 10.1039/d1nr07684a.
The interaction between nanomaterials and phospholipid membranes underlies many emerging biological applications. To what extent hydrophilic phospholipid heads shield the bilayer from the integration of hydrophobic nanomaterials remains unclear, and this open question contains important insights for understanding biological membrane physics. Here, we present molecular dynamics (MD) simulations to clarify the resistance of phospholipid heads to the membrane penetration of graphene nanosheets. With 130 simulation trials, we observed that ∼22% graphene nanosheets penetrate the POPC bilayer. Sharp corners of the nanosheets should have a lower energy barrier than nanosheet edges, but interestingly, the membrane penetration mainly starts from the edge-approaching orientation. We thoroughly analyzed the pentration pathway and propulsion, indicating that the membrane penetration of graphene nanosheets is dominated by the joint effects of nanosheet edges and corners. Furthermore, the molecular origin of the resistance is clarified by evaluating the bilayers of different phospholipids, which successfully correlates the penetration resistance of phospholipid heads with the correlated motions of neighboring phospholipids for the first time. These results are expected to inspire future studies on the dynamic behavior of phospholipids, bio-nano interfaces, and design of biological nanomaterials.
纳米材料与磷脂膜的相互作用是许多新兴生物应用的基础。亲水磷脂头在多大程度上保护双层膜不受疏水性纳米材料的整合仍不清楚，这个悬而未决的问题对于理解生物膜物理具有重要的见解。在这里，我们通过分子动力学（MD）模拟来阐明磷脂头对石墨烯纳米片穿透磷脂膜的阻力。通过 130 次模拟试验，我们观察到约 22%的石墨烯纳米片穿透 POPC 双层膜。纳米片的尖角应该比纳米片边缘具有更低的能量势垒，但有趣的是，膜的穿透主要从边缘接近的方向开始。我们彻底分析了穿透途径和推进，表明石墨烯纳米片的膜穿透主要由纳米片边缘和拐角的共同作用决定。此外，通过评估不同磷脂的双层膜，阐明了穿透阻力的分子起源，这是首次成功地将磷脂头的穿透阻力与相邻磷脂的相关运动相关联。这些结果有望激发未来对磷脂动力学、生物纳米界面和生物纳米材料设计的研究。
