D. POPESCU*, I. STELIAN*, A.G. POPESCU**, NICOLETA NEACŞU, MARIA-LUISA FLONTA

Department of Biophysics & Physiology, Faculty of Biology, University of Bucharest, 91-95, Splaiul Independenţei, Bucharest, Romania
*Institute of Statistics Mathematics and Applied Mathematics, Calea 13 Septembrie, Bucharest, Romania
**Faculty of Automatics and Computers Control, “Politehnica” University, 313, Splaiul Independenţei, Bucharest, Romania

Abstract. In this work we have determined the parameters of transbilayer pore formation induced by the collective thermal motion (CTM) of phospholipid bilayer molecules. Using the general theory of continuous elastic media we have designed a simple model of pore formation. The pore radius calculus describes in mathematical terms the lipid bilayer fluctuations, which give rise to different types of pores: open stable pores, closed stable pores (zippered pores) and unstable open pores (which determine the membrane breakdown). After bilayer deformation, the sinusoidal torus becomes an elliptical torus. Equating the volumes of these geometrical shapes, we obtain the mathematical expression of the pore radius. Comparing the pore radius with the hydrophobic bilayer thickness, the pore stability can be estimated. The effect of different degrees of polar groups hydration on the thermoporation process was analyzed.

Corresponding author’s e-mail: popescu@bio.bio.unibuc.ro

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