l-DOPA modulates the kinetics but not the thermodynamic equilibrium of TTA+ amphiphiles forming lyotropic nematic liquid crystals

Abstract

Lyotropic liquid crystals (LLCs) are mixtures of amphiphile molecules usually studied as mimetic of biological membrane. The equilibrium dynamics of tetradecyltrimethyl ammonium cation (TTA⁺) molecules forming nematic LLCs (LNLCs) is guided by a dive-in mechanism where TTA⁺ molecules spontaneously leave and re-enter the bicelle. Of note, this dynamic behavior could be exploited to produce drug nano-delivery systems based on LNLCs. Therefore, the understanding of the effect of pharmaceutically interesting molecules in the dynamics of the dive-in mechanism should be crucial for drug delivery applications. In this work, we studied the effects of L-DOPA in the equilibrium dynamics of TTA⁺ bicelles forming LNLCs, employing a transdisciplinary approach based on ²H-NMR together with molecular modeling and molecular dynamics simulations. Our data suggest that L-DOPA perturbs the kinetic of the dive-in mechanism but not the thermodynamics of this process. As whole, our results provide fundamental insights on the mechanisms by which L-DOPA govern the equilibrium of LNLCs bicelles.