title: Diffusion and Directionality of Charged Nanoparticles on Lipid Bilayer Membrane.
abstract: Diffusion dynamics of charged nanoparticles on the lipid membrane is of essential importance to cellular functioning. Yet a fundamental insight into electrostatics-mediated diffusion dynamics of charged nanoparticles on the membrane is lacking and remains to be an urgent issue. Here we present the computational investigation to uncover the pivotal role of electrostatics in the diffusion dynamics of charged nanoparticles on the lipid membrane. Our results demonstrate diffusive behaviors and directional transport of a charged nanoparticle, significantly depending on the sign and spatial distribution of charges on its surface. In contrast to the Fickian diffusion of neutral nanoparticles, randomly charged nanoparticles undergo superdiffusive transport with directionality. However, the dynamics of uniformly charged nanoparticles favors Fickian diffusion that is significantly enhanced. Such observations can be explained in term of electrostatics-induced surface reconstruction and fluctuation of lipid membrane. We finally present an analytical model connecting surface reconstruction and local deformation of the membrane. Our findings bear wide implications for the understanding and control of the transport of charged nanoparticles on the cell membrane.
authors.affiliation: Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Pengyu
authors.initials: P
authors.lastname: Chen
authors.affiliation: Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Zihan
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Junshi
authors.initials: J
authors.lastname: Liang
authors.affiliation: Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Tianqi
authors.initials: T
authors.lastname: Cui
authors.affiliation: School of Science, Beijing Jiaotong University , Beijing 100044, China.
authors.forename: Xinghua
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Miao
authors.affiliation: Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Li-Tang
authors.identifier: 0000-0002-6090-3039
authors.initials: LT
authors.lastname: Yan
mesh_terms: D002462:Cell Membrane; D004058:Diffusion; D008051:Lipid Bilayers; D053758:Nanoparticles; D055672:Static Electricity
chemical_list: D008051:Lipid Bilayers
keywords: Saffman−Delbrück theory; charged nanoparticle; diffusion; lipid membrane; surface reconstruction