管间相互作用对细胞膜包裹碳纳米管的影响  

Effects of Interaction Between Carbon Nanotubes on Membrane-Wrapped Carbon Nanotubes

作　　者：陈鸿韬 吴凯 梁桃 修鹏 CHEN Hongtao;WU Kai;LIANG Tao;XIU Peng(Department of Engineering Mechanics,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学工程力学系,杭州310027

出　　处：《医用生物力学》2022年第3期441-447,共7页Journal of Medical Biomechanics

基　　金：国家自然科学基金项目(11574268,11932017);中央高校基本科研业务费专项资金(2017QNA4033)。

摘　　要：目的针对平行放置于细胞膜表面的两单壁碳纳米管系统,探究两碳管间相互作用对膜包裹碳管方式的影响,并给出能量最优的构象。方法建立考虑两根碳管间范德华相互作用的膜包裹碳管的力学模型,并引入反映细胞膜形态的参数以及描述碳管相对位置的参数。利用基于Helfrich自由能的连续介质力学建模,计算膜弯曲能量,并利用Lennard-Jones势描述碳管之间的相互作用。通过查表法计算系统不同位置的自由能,并给出细胞膜包裹碳管的典型结构。结果与未考虑管间相互作用的情况相比,系统自由能曲线出现了较大改变:在碳管间距约为0.3倍管半径时,能量曲线上出现深势阱;随着碳管间距增大,自由能恢复到没有管间相互作用能时的大小。结论引入碳管间相互作用能后,膜包裹碳管的方式发生变化,两碳管倾向于以触碰到一起的方式进行协同胞吞。研究结果为理解并设计基于纳米管的药物输运系统提供理论借鉴。Objective For the system of two single-walled carbon nanotubes(CNTs)placed in parallel onto a cell membrane,effects of the interaction between carbon nanotubes on wrapping manner of carbon tubes by the membrane were investigated,and the energy-optimized configurations were obtained.Methods A physical model for membrane-wrapped CNTs considering the interaction between two CNTs,and parameters describing the morphology of cell membrane and positions of CNTs were introduced.The Helfrich model based on continuum mechanics was used to calculate the membrane’s bending energy and the Lennard-Jones potential was introduced to describe the interaction between CNTs.Free energy of the system at different distances of NTs was calculated by the look-up table method,and the typical configurations of the membrane-wrapped CNTs was obtained.Results Compared with the case wherein the interaction between CNTs was not considered,the free energy profile of the system significantly changed.Deep well appeared on energy curve,when the distance between CNTs of carbon was 0.3 times of the tube diameter;as the distance between CNTs increased,the energy returned to the case wherein the interaction between CNTs was not considered.Conclusions With introduction of the interaction between CNTs,the wrapping manner of CNTs by the cell membrane changed,and the two CNTs tended to contact during their endocytosis.These results provide theoretical references for understanding and developing novel nanotube-based system for drug delivery.

关 键 词：细胞膜力学 碳纳米管 胞吞 Helfrich模型 范德华作用 

分 类 号：R318.01[医药卫生—生物医学工程]