Polynucleotides in cellular mimics: Coacervates and lipid vesicles

Vieregg, Jeffrey; Tang, T-Y Dora

doi:10.1016/j.cocis.2016.09.004

Cited by 44 publications

(40 citation statements)

References 82 publications

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“…This strong uptake of molecules into complex coacervates is largely driven by electrostatic interactions, although other factors, such as protein conformation or persistence length, also influence the partitioning. Thanks to its negatively charged backbone, for example, RNA is generally taken up effectively …”

Section: Resultsmentioning

confidence: 99%

Physicochemical Characterization of Polymer‐Stabilized Coacervate Protocells

et al. 2019

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The bottom‐up construction of cell mimics has produced a range of membrane‐bound protocells that have been endowed with functionality and biochemical processes reminiscent of living systems. The contents of these compartments, however, experience semidilute conditions, whereas macromolecules in the cytosol exist in protein‐rich, crowded environments that affect their physicochemical properties, such as diffusion and catalytic activity. Recently, complex coacervates have emerged as attractive protocellular models because their condensed interiors would be expected to mimic this crowding better. Here we explore some relevant physicochemical properties of a recently developed polymer‐stabilized coacervate system, such as the diffusion of macromolecules in the condensed coacervate phase, relative to in dilute solutions, the buffering capacity of the core, the molecular organization of the polymer membrane, the permeability characteristics of this membrane towards a wide range of compounds, and the behavior of a simple enzymatic reaction. In addition, either the coacervate charge or the cargo charge is engineered to allow the selective loading of protein cargo into the coacervate protocells. Our in‐depth characterization has revealed that these polymer‐stabilized coacervate protocells have many desirable properties, thus making them attractive candidates for the investigation of biochemical processes in stable, controlled, tunable, and increasingly cell‐like environments.

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Section: Resultsmentioning

confidence: 99%

Physicochemical Characterization of Polymer‐Stabilized Coacervate Protocells

et al. 2019

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“…The resulting self-assembled core-shell nanoparticles are variously referred to as polyelectrolyte complex micelles (PCMs), polyion complex micelles, block ionomer complexes, or coacervate-core micelles by analogy to surfactant micellization, even though all components of the system are hydrophilic 6,7 . PCMs' ability to encapsulate hydrophilic molecules such as proteins and nucleic acids, as well as the extensive tunability offered by the block copolymer carrier architecture makes them attractive candidates for delivering therapeutic molecules in vivo [8][9][10][11][12][13] .…”

Section: Introductionmentioning

confidence: 99%

Assembly and Characterization of Polyelectrolyte Complex Micelles

Marras

Vieregg

Tirrell

2020

JoVE

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Polyelectrolyte complex micelles (PCMs), core-shell nanoparticles formed by selfassembly of charged polymers in aqueous solution, provide a powerful platform for exploring the physics of polyelectrolyte interactions and also offer a promising solution to the pressing problem of delivering therapeutic oligonucleotides in vivo. Developing predictive structure-property relationships for PCMs has proven difficult, in part due to the presence of strong kinetic traps during nanoparticle self-assembly. This article discusses criteria for choosing polymers for PCM construction and provides protocols based on salt annealing that enable assembly of repeatable, low-polydispersity nanoparticles. We also discuss PCM characterization using light scattering, small-angle X-ray scattering, and electron microscopy. Polymer selection and preparationPCM properties are strongly influenced by the physical and chemical characteristics of the constituent polymers, making polymer selection a critical step in the design process. The most well-characterized block copolymers for nucleic acid PCMs are linear diblocks such as poly(lysine)-poly(ethylene glycol) (pLys-PEG), but PCMs can be formed between polyelectrolytes and a variety of hydrophilic neutral-charged polymers, which can be

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“…The droplets disassemble and reassemble under UV and blue light, respectively,d ue to azobenzene trans/cis photoisomerisation. [14] Polynucleotides have been used as scaffold components to assemble coacervate droplets, [15][16][17][18][19] and selective sequestration of guest polynucleotides has been demonstrated in preformed coacervates. [1,2] They play acrucial role for example in the compaction of polynucleotides and regulation of genetic expression.…”

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confidence: 99%

“…[3,4] Microdroplets produced in vitro by associative (coacervates) or segregative (aqueous two-phase systems) liquid-liquid phase separation have recently been used as synthetic models of dynamic protocells. [14] Polynucleotides have been used as scaffold components to assemble coacervate droplets, [15][16][17][18][19] and selective sequestration of guest polynucleotides has been demonstrated in preformed coacervates. [14] Polynucleotides have been used as scaffold components to assemble coacervate droplets, [15][16][17][18][19] and selective sequestration of guest polynucleotides has been demonstrated in preformed coacervates.…”

mentioning

confidence: 99%

“…[5][6][7] These membrane-free molecularly crowded compartments seques-ter functional biomolecules [5,8] and support enzymatic activity, [9,10] protein folding, [11] RNAc atalysis, [12,13] and cell-free protein expression. [14] Polynucleotides have been used as scaffold components to assemble coacervate droplets, [15][16][17][18][19] and selective sequestration of guest polynucleotides has been demonstrated in preformed coacervates. [12,20,21] Owing to their liquid-like nature and the weak molecular interactions,s ynthetic coacervate droplets can dynamically respond to external stimuli.…”

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confidence: 99%

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Photoswitchable Phase Separation and Oligonucleotide Trafficking in DNA Coacervate Microdroplets

et al. 2019

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Coacervate microdroplets produced by liquid-liquid phase separation have been used as synthetic protocells that mimic the dynamical organization of membrane-free organelles in living systems.A chieving spatiotemporal control over droplet condensation and disassembly remains challenging. Herein, we describe the formation and photoswitchable behavior of light-responsive coacervate droplets prepared from mixtures of double-stranded DNAa nd an azobenzene cation. The droplets disassemble and reassemble under UV and blue light, respectively,d ue to azobenzene trans/cis photoisomerisation. Sequestration and release of captured oligonucleotides followt he dynamics of phase separation such that light-activated transfer,m ixing,h ybridization, and trafficking of the oligonucleotides can be controlled in binary populations of the droplets.O ur results open perspectives for the spatiotemporal control of DNAc oacervates and provide as tep towards the dynamic regulation of synthetic protocells.The dynamic compartmentalization of biological components in space and time is ah allmark of functional synchronization in living cells.Biomolecular condensates formed via liquid-liquid phase separation are dynamic subcellular compartments that are actively formed and dissolved in response to environmental cues. [1,2] They play acrucial role for example in the compaction of polynucleotides and regulation of genetic expression. [3,4] Microdroplets produced in vitro by associative (coacervates) or segregative (aqueous two-phase systems) liquid-liquid phase separation have recently been used as synthetic models of dynamic protocells. [5][6][7] These membrane-free molecularly crowded compartments seques-ter functional biomolecules [5,8] and support enzymatic activity, [9,10] protein folding, [11] RNAc atalysis, [12,13] and cell-free protein expression. [14] Polynucleotides have been used as scaffold components to assemble coacervate droplets, [15][16][17][18][19] and selective sequestration of guest polynucleotides has been demonstrated in preformed coacervates. [12,20,21] Owing to their liquid-like nature and the weak molecular interactions,s ynthetic coacervate droplets can dynamically respond to external stimuli. [7,22,23] Fori nstance,t heir formation and dissolution has been achieved by changes in pH, [5] temperature, [24][25][26] ionic strength, [27,28] and more recently by enzymemediated catalytic activity. [15,[29][30][31][32] However,p latforms enabling the rapid and localized actuation of polynucleotide microphase separation have not yet been developed. Due to its favourable spectral and spatiotemporal capabilities,l ight holds great promise as aprogrammable trigger for controlling the reversible assembly and disassembly of coacervate droplets.L ight has been used to control synthetic microcompartments, [33][34][35] trigger biomolecular condensation in cellulo via optogenetic tools, [36,37] promote the dynamical shaping of soft colloids, [38] and induce the reversible compaction of single DNAc hains. [39][40][41] Here,w ee xploit t...

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Polynucleotides in cellular mimics: Coacervates and lipid vesicles

Cited by 44 publications

References 82 publications

Physicochemical Characterization of Polymer‐Stabilized Coacervate Protocells

Physicochemical Characterization of Polymer‐Stabilized Coacervate Protocells

Assembly and Characterization of Polyelectrolyte Complex Micelles

Photoswitchable Phase Separation and Oligonucleotide Trafficking in DNA Coacervate Microdroplets

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