Influence of Wet–Dry Cycling on the Self-Assembly and Physicochemical Properties of Model Protocellular Membrane Systems

Graphical Abstract

Survival of the fittest: In this work, the influence of wet-dry cycling on the self-assembly and physicochemical properties of model protocellular membranes was studied. It was demonstrated that wet-dry cycling can increase their encapsulation efficiency and impinge upon the membrane composition, thereby affecting their physicochemical properties. This underscores the imminent implications wet-dry cycling would have had for protocell evolution.

Abstract

Wet-dry cycles are hypothesized to facilitate fundamental steps towards the emergence of life on prebiotic Earth. Multiple wet–dry cycles have been demonstrated to promote biopolymer formation. However, the effect of recurring wet-dry cycles on the self-assembly and physicochemical properties of model protocellular membranes remains somewhat obscure. Towards this end, we evaluated the structural and chemical stability of composite model protocell membrane systems composed of single chain amphiphiles, under wet-dry cycles. The change in membrane properties, size and encapsulation was also investigated. Model protocellular membrane systems were found to reassemble into vesicles even over multiple cycling. Wet-dry cycling induced compositional changes in the membranes, leading to changes in their physicochemical properties. Multiple cycles were also found to increase vesicular encapsulation of calcein. This work outlines how wet-dry cycling on the early Earth could have helped in the formation of protocellular entities and their evolution on prebiotic Earth.