Dynamic Vesicles Formed By Dissipative Self‐Assembly

Abstract

Synthetic lipid membranes have served as important models for cellular membranes. However, these static membranes do not recapitulate the dynamic nature of the biological membranes which are frequently remodeled to support cellular function. An ideal membrane model would thus also display dynamic exchange of lipids. In this work, we achieve such a system by coupling the self‐assembly of peptides into membranes with a chemical reaction cycle. The reaction cycle activates and deactivates the peptides for self‐assembly at the expense of a chemical fuel. The resulting membranes are dynamically remodeled, and, over their 40 min lifetime, they emerge, grow, and are torn apart before they eventually decay.

Active coacervate droplets as a model for membraneless organelles and protocells

“…Such kinetic regulation is inspired by biology's mode of controlling assemblies like the membraneless organelles. Examples of synthetic dissipative assemblies include fibers driven by photochemical 35 or fuel-driven reaction cycles, [36][37][38][39][40] vesicles driven by ATP 41 or carbodiimides, 42 and others. 43 In this work, we thus introduce a model for membraneless organelles based on complex coacervate droplets regulated by a fuel-driven chemical reaction cycle.…”

Robust Dynamics of Synthetic Molecular Systems as a Consequence of Broken Symmetry

“…A recently proposed concept, 'dissipative self-assembly', seems to share the same issues [74][75][76][77][78][79]. However, from the author's standpoint, the claims of dissipative self-assembly are still unclear and weak in the aspect of the distancing from equilibrium; most of the papers reported consecutive reactions where the intermedium products were assemblies and claimed that the assembled state can be maintained through continuous substance supply [72,73,[80][81][82][83][84][85][86][87]. The structure of such nonequilibrium systems is not a dissipative structure, according to Prigogine [3].…”

Devising Synthetic Reaction Cycles for Dissipative Nonequilibrium Self‐Assembly

“…The size of the assemblies could be tuned by adding different amounts of the fuel and the pathway complexity depends on the preparative method. Owing to the broadly applicable functional group and the easily purchased fuels, the system has been used in different examples and applications such as: the dissipative assembly of macrocycles that act similarly to crown ethers;40 regulating the assembly of luminescent silicon nanocrystals that were used to delay the delivery of silicon into mammalian cells;43 the chemically fueled cross‐linking of polymers, showing a transient increase in strength of the obtained materials;44 the formation of dynamic vesicles that have a controlled lifetime and can grow, change morphology, and be destroyed spontaneously by the addition of fuel;46 and the transient gel‐to‐gel transition from one architecture to another, of an amino‐acid containing gelator 47…”

“…The desired reaction cycles can be divided into the following categories: Cat. (1) when spontaneous deactivation of the self‐assembling molecules occurs by the solvent (e.g., hydrolysis by water);36–47 Cat. (2) where the same chemistry (catalyzed or not) is responsible for all activation and/or deactivation steps;48–50 Cat.…”