THE INFLUENCE OF THE EXTERNAL BATH ON THE NUMBER OF CYCLES OF A LIPID UNILAMELLAR VESICLE UNDER HYPOTONIC CONDITIONS

D. POPESCU#, A.G. POPESCU

Department of Mathematical Modelling in Life Sciences, Institute of Mathematical Statistics and Applied Mathematics, 13, Calea 13 Septembrie, Bucharest-050711, Romania

In this paper we consider a unilamellar vesicle (i.e., a liposome) filled with an aqueous solution of an osmotic solute, inserted into a spherical closed box filled with water. Due to the mechanical tension induced by the osmotic flow, the lipid vesicle swells up to a critical size, when suddenly only one transient pore appears. The appearance of the pore changes the sense of the liposome evolution. A part of internal solution comes out of the liposome through transmembrane pore in the aqueous medium from closed box. The liposome relaxes up to the initial size, when the pore is closed and another cycle can begin. Therefore, the liposome performs a periodic dynamic process. The differential equation that describes the swelling stage of the pulsatory liposome during each cycle of its running time, when it is inserted in a closed environment (a closed bath) was obtained. Such liposomes may be used, in the future, in medical applications, as devices for controlled drug delivery to ill tissues In tissues, the drug charged liposomes will work inside a closed space, where it will thus delivering the drug.

Key words: pulsatory liposome, osmotic stress, liposome swelling.

Corresponding author’s e-mail: dghpopescu@gmail.com

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