Life-Inspired Endogenous Dynamic Behavior of Lipid Droplet-like Microcompartments in Artificial Adipocyte-like Structures

Chemical systems that can replicate cellular behaviors are gaining increasing attention and are being used to study various biological processes.Here,a protein-or amylose-based assembly at an oil/water interface was employed to construct a large compartmentalized adipocyte-like structure,and a lipid droplet-like microcompartment(amylose-polymerstabilized 2-ethyl-1-hexanol microcompartment),which exhibits floating behaviors driven by the amylose-polymer micelle solubilization,was introduced inside these adipocyte-like structures.When the lipase-based catalytic reaction and the external oil composition were controlled and another lipid droplet-like microcompartment(lipase-stabilized tributyrin microcompartment)was introduced,then a series of dynamic behaviors were exhibited by the two types of lipid droplet-like microcompartments,including growth,self-sorting,and fusion within the adipocyte-like structures.Therefore,it is anticipated that this autonomous generation of hierarchical multicompartments represents a breakthrough compared to the traditional bottom-up strategies,and the artificial life systems we studied could contribute a chemical-based strategy of understanding the process of lipid droplet growth and fusion inside a living adipocyte cell.

Bacterial microcompartment-mimicking Pickering emulsion droplets for detoxification of chemical threats under sweet conditions

Chemical warfare agents represent a severe threat to mankind and their efficient decontamination is a global necessity.However,traditional disposal strategies have limitations,including high energy consumption,use of aggressive reagents and generation of toxic byproducts.Here,inspired by the compartmentalized architecture and detoxification mechanism of bacterial microcompartments,we constructed oil-in-water Pickering emulsion droplets stabilized by hydrogen-bonded organic framework immobilized cascade enzymes for decontaminating mustard gas simulant(2-chloroethyl ethyl sulfide,CEES)under sweet conditions.Two exemplified droplet systems were developed with two-enzyme(glucose oxidase/chloroperoxidase)and threeenzyme(invertase/glucose oxidase/chloroperoxidase)cascades,both achieving over 6-fold enhancement in decontamination efficiency compared with free enzymes and>99% selectivity towards non-toxic sulfoxide.We found that the favored mass transfer of sugars and CEES from their respective phases to approach the cascade enzymes located at the droplet surface and the facilitated substrate channeling between proximally immobilized enzymes were key factors in augmenting the decontamination efficacy.More importantly,the robustness of immobilized enzymes enabled easy reproduction of both the droplet formation and detoxification performance over 10 cycles,following long-term storage and in far-field locations.