Acceleration of lipid reproduction by emergence of microscopic motion

Abstract

Self-reproducing molecules abound in nature where they support growth and motion of living systems. In artificial settings, chemical reactions can also show complex kinetics of reproduction, however integrating self-reproducing molecules into larger chemical systems remains a challenge towards achieving higher order functionality. Here, we show that self-reproducing lipids can initiate, sustain and accelerate the movement of octanol droplets in water. Reciprocally, the chemotactic movement of the octanol droplets increases the rate of lipid reproduction substantially. Reciprocal coupling between bond-forming chemistry and droplet motility is thus established as an effect of the interplay between molecular-scale events (the self-reproduction of lipid molecules) and microscopic events (the chemotactic movement of the droplets). This coupling between molecular chemistry and microscopic motility offers alternative means of performing work and catalysis in micro-heterogeneous environments.

Self‐Sustained Marangoni Flows Driven by Chemical Reactions**

“…Controlling the chemistry of such reaction-driven Marangoni flows becomes then an interesting approach to achieve complex behavior at air-water interfaces and within organic droplets. [44][45][46] Such insight is also useful to develop applications where Marangoni flows are used for propulsion, [47,48] self-assembly direction [49][50][51] or to design systems with Marangoni-based feedback mechanisms. [52]…”

Self-Propelled Motion of an Oil Droplet Containing a Phospholipid and its Stability in Collectivity

“…We could observe that Marangoni convection (blue arrow) occurred inside the droplet because ejection points were transported along the interface. Therefore, we inferred that this convection, which has been identified as the primary driving force in many selfpropelled droplet systems, was the cause of the self-propulsion of the droplet in this system [40][41][42][43][44][45][46]. In general, Marangoni convection occurs when the interfacial tension γ at the droplet interface becomes unbalanced.…”

“…In this phenomenon, surfactant molecules first enter the lipid membrane with an increasing surfactant concentration, and aggregates of the surfactant and lipid molecules are formed as surfactant concentration is increased further. Furthermore, another study showed that solubilization, namely micellization of surfactants with oil, and ejection of solubilized emulsions proceed when the concentration of the surfactant at the droplet interface exceeds a threshold value [46]. Therefore, we infer that, in this study, TSA + is first inserted into the self-assembled DMPC monolayer surrounding the droplet, and aggregated emulsions are formed and ejected them owing to the solubilization promoted by the micellization among TSA + , DMPC, and nitrobenzene oil when the concentration of the inserted TSA + exceeds a threshold value.…”

Self-organization at air-water interfaces emerging from Marangoni and elastocapillary effects directed by amphiphile filament connections.

“…This imbalance results in an internal Marangoni flow, which propels the droplet towards the side with the highest surfactant concentration. 25,26,28 Alternatively, self-organizing elements can interact via capillary effects, which involve the deformation of a liquid interface caused by objects in contact with it. 29 Capillary forces have been demonstrated to deform elastic microstructures, 30,31 even causing them to collapse into hierarchical assemblies.…”