Reaction kinetics and mechanical models of liposome adhesion at charged interface

Abstract

Dynamics of adhesion of single liposome at the charged mercury interface is analyzed 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 monolayer. 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 emphasizes 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 in the wide potential range and offer a complementary insight into the dynamics of single adhesion event, which can find application in studies of cell adhesion and in drug delivery.