engleski

Dynamics of liposome adhesion at electrified interface

The dynamics of interaction of single liposome with a charged mercury electrode strongly depends on the adhesion forces which can be potentiostatically controlled by surface charge density and by interfacial tension. Dynamics of adhesion is analysed through its amperometric signal using a reaction kinetics model and a mechanical model. We present analytical solutions of the reaction kinetics model for decoupling and identifying temporal evolution of three distinct states: i) the initial state corresponding to an intact liposome, ii) the intermediate state where the liposome is partly deformed, and iii) the final state of a lipid layer formation. The results obtained with this model indicate that all three states simultaneously evolve from the onset of the adhesion process. The new mechanical model provides a physical interpretation of the three states and emphasises the role of the forces involved in liposome adhesion process. The main conclusion is that the water content of the liposome is released through the pores formed in the membrane rather than through the channels parallel to the electrode. Both models reproduce the measurements well. By combining the predictions of the two models, we demonstrate how to associate various features of the amperometric signal with the states of an adhesion event, and how to capture geometry of spherical liposome at the electrode. The complementary information extracted from the two models is important for better understanding of the adhesion mechanisms of soft organic particles at charged interfaces. These results may well be useful in related biological studies involving cell adhesion, cell activity, and cell fusion.

electrified interface; liposome adhesion; mechanical model; reaction kinetics model

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