Mechanics of lipid bilayer junctions affecting the size of a connecting lipid nanotube
Artikel i vetenskaplig tidskrift, 2011

In this study we report a physical analysis of the membrane mechanics affecting the size of the highly curved region of a lipid nanotube (LNT) that is either connected between a lipid bilayer vesicle and the tip of a glass microinjection pipette (tube-only) or between a lipid bilayer vesicle and a vesicle that is attached to the tip of a glass microinjection pipette (two-vesicle). For the tube-only configuration (TOC), a micropipette is used to pull a LNT into the interior of a surface-immobilized vesicle, where the length of the tube L is determined by the distance of the micropipette to the vesicle wall. For the two-vesicle configuration (TVC), a small vesicle is inflated at the tip of the micropipette tip and the length of the tube L is in this case determined by the distance between the two interconnected vesicles. An electrochemical method monitoring diffusion of electroactive molecules through the nanotube has been used to determine the radius of the nanotube R as a function of nanotube length L for the two configurations. The data show that the LNT connected in the TVC constricts to a smaller radius in comparison to the tube-only mode and that tube radius shrinks at shorter tube lengths. To explain these electrochemical data, we developed a theoretical model taking into account the free energy of the membrane regions of the vesicles, the LNT and the high curvature junctions. In particular, this model allows us to estimate the surface tension coefficients from R(L) measurements.

membrane nanotubes


tether formation






Roger Karlsson

Göteborgs universitet

Michael Kurczy

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Richards Grzhibovskis

Universitat des Saarlandes

Kelly L. Adams

Göteborgs universitet

Andrew Ewing

Göteborgs universitet

Ann-Sofie Cans

Chalmers, Kemi- och bioteknik, Analytisk kemi

Marina Voinova

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Nanoscale Research Letters

1931-7573 (ISSN) 1556-276X (eISSN)

Vol. 6 1-6 421