Lipid Vesicle-Coated Complex Coacervates

Abstract

Compartmentalization by complex coacervation is important across a range of different fields including subcellular and prebiotic organization, biomedicine, food science, and personal care products. Often, lipid selfassemblies such as vesicles are also present intracellularly or in commercial formulations. A systematic understanding of how phospholipid vesicles interact with different complex coacervates could provide insight and improve control over these systems. In this manuscript, anionic phospholipid vesicles were added to a series of different complex coacervate samples in which coacervates were formed by mixing one of five polycations with one of three (poly)anions that varied in chemical structure and length. Vesicles were found to assemble at the coacervate/continuous phase interface and/or form aggregates. We report how factors such as the charge density of polyelectrolytes and the charge ratio of cationic-to-anionic moieties impact the vesicle distribution in coacervate samples. Our findings emphasize the importance of interactions between vesicles and polycations in the dilute supernatant phase for determining whether the vesicles aggregate prior to assembly at the liquid−liquid interface. The uptake of an RNA oligonucleotide (A 15 ) was also investigated to understand the effect of these liposome coatings on diffusion into coacervate droplets. Systems in which uniform vesicle coronas assemble around coacervate droplets without restricting the entry of biomolecules such as RNAs could be of interest as bioreactors.

Prebiotically-relevant low polyion multivalency can improve functionality of membraneless compartments

“…Turbidity was calculated using UV-Vis absorbance at 500 nm measured by Tecan M1000 Pro microplate reader. Turbidity alone cannot discriminate between aggregates and coacervates solutions 51 . Therefore, samples were also imaged with a Nikon Eclipse TE200 inverted optical microscope to test the presence of coacervate droplets.…”

Origin of Species before Origin of Life: The Role of Speciation in Chemical Evolution

“…Such systems can be of varying structural and functional complexity and could be produced from either associative (such as in complex coacervates [ 105 , 106 , 107 ]) or segregative (such as in polyethylene glycol (PEG) and dextran aqueous two-phase systems [ 78 , 108 ]) phase separation [ 109 ]. Other prebiotically plausible compartment systems have also been proposed, such as rock pores [ 110 , 111 ], polyester microdroplets [ 112 , 113 ], supercritical carbon dioxide droplets [ 114 , 115 ], or even combinations of different membraneless and membrane-bound systems [ 116 , 117 , 118 , 119 , 120 ].…”

A self-templated route to monodisperse complex droplets as artificial extremophile-mimic from coacervate-liposome interplay

“…Particles with | ζ | below 10 mV, between 10 mV to 40 mV, or above 40 mV preferentially locate in the dilute phase, interface, or coacervate phase, respectively, in agreement with our hypothesis. The interfacial tension driven partitioning behavior arising from particle-polymer association might account for the various cargo recruitment behaviors in synthetic coacervates 21,23 and biomolecular condensates 28 . For instance, negatively charged lipids were reported to be necessary for the recruiment of vesicles in synapsin condensates 28 .…”