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

RSC Adv. 2020 Apr 17;10(26):15366-15374. doi: 10.1039/d0ra00764a. eCollection 2020 Apr 16.

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.