Eur. Phys. J. E 7, 381-386 (2002)
DOI: 10.1140/epje/i2001-10103-x

Membrane-mediated interactions of rod-like inclusions

P. Biscari¹ and F. Bisi<sup>2

1</sup>  Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy and Istituto Nazionale di Fisica della Materia, via Ferrata 1, 27100 Pavia, Italy
²  Dipartimento di Matematica, Università di Pavia, via Ferrata 1, 27100 Pavia, Italy and Istituto Nazionale di Fisica della Materia, via Ferrata 1, 27100 Pavia, Italy

paolo.biscari@polimi.it
bisi@dimat.unipv.it

(Received 22 October 2001 and Received in final form 8 March 2002)

Abstract
Inclusions embedded in lipid membranes undergo a mediated force, due to the tendency of the membrane to relax its excess of elastic energy. In this paper we determine the exact shape of a two-dimensional vesicle hosting two different inclusions, and we analyse how the inclusion conformation influences the mediated interaction. We find non-trivial equilibrium configurations for the inclusions along the hosting membrane, and we derive the complete phase diagram of the mediated interaction. In particular, we find a non-vanishing mediated force even when the distance between the inclusions is much greater than their size. Our model can be applied to describe the mediated interactions of parallel, elongated inclusions embedded in three-dimensional membranes.

PACS
87.16.Dg - Membranes, bilayers, and vesicles.
34.20.Gj - Intermolecular and atom-molecule potentials and forces.


© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2002