pH-responsive self-assembled compartments as tuneable model protocellular membrane systems

Abstract

Prebiotically plausible single-chain amphiphiles are enticing as model protocellular compartments to study the emergence of cellular life owing to their self-assembling properties. Here, we investigated the self-assembly behaviour of mono-N-dodecyl phosphate (DDP) and mixed systems of DDP with 1-dodecanol (DDOH) at varying pH conditions. Membranes composed of DDP showed pH-responsive vesicle formation in a wide range of pH with a low critical bilayer concentration (CBC). Further, the addition of DDOH to DDP membrane system enhanced vesicle formation and stability in alkaline pH regimes. We also compared the high-temperature behaviour of DDP and DDP:DDOH membranes with conventional fatty acid membranes. Both, DDP and DDP:DDOH mixed membranes possess packing that is similar to decanoic acid membrane. However, the micropolarity of these systems are similar to phospholipid membranes. Finally, the pH-dependent modulation of different phospholipid membranes doped with DDP was also demonstrated to engineer tuneable membranes with potential translational implications.