title: Point-to-Plane Nonhomogeneous Electric-Field-Induced Simultaneous Formation of Giant Unilamellar Vesicles (GUVs) and Lipid Tubes.
abstract: It is well-known that homogeneous electric fields can be used to generate giant unilamellar vesicles (GUVs). Herein we report an interesting phenomenon of formation of GUVs and lipid tubes simultaneously using a nonhomogeneous electric field generated by point-to-plane electrodes. The underlying mechanism was analyzed using finite element analysis. The two forces play main roles, that is, the pulling force (F) to drag GUVs into lipid tubes induced by fluid flow, and the critical force (Fc) to prevent GUVs from deforming into lipid tubes induced by electric fields. In the center area underneath the needle electrode, the GUVs were found because F is less than Fc in that region, whereas in the edge area the lipid tubes were obtained because F is larger than Fc. The diffusion coefficient of lipid in the tubes was found to be 4.45 μm(2)  s(-1) using a fluorescence recovery after photobleaching (FRAP) technique. The method demonstrated here is superior to conventional GUV or lipid tube fabrication methods, and has great potential in cell mimic or hollow material fabrication using GUVs and tubes as templates.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Chemical Engineering and Technology, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, P. R. China.
authors.forename: Chuntao
authors.initials: C
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Chemical Engineering and Technology, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, P. R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Chemical Engineering and Technology, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, P. R. China.
authors.forename: Yinan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Chemical Engineering and Technology, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, P. R. China.
authors.forename: Qingchuan
authors.initials: Q
authors.lastname: Li
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Chemical Engineering and Technology, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, P. R. China. muwei@hit.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Mu
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Chemical Engineering and Technology, Harbin Institute of Technology, 92 West Da-Zhi Street, Harbin, 150001, P. R. China. hanxiaojun@hit.edu.cn.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Han
mesh_terms: D004560:Electricity; D008055:Lipids / Q000737:chemistry*; D008856:Microscopy, Fluorescence; D053835:Unilamellar Liposomes / Q000737:chemistry*
chemical_list: D008055:Lipids; D053835:Unilamellar Liposomes
keywords: electroformation; finite element analysis; fluorescence recovery after photobleaching; giant unilamellar vesicles; lipid tube