1
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Fielden SDP. Kinetically Controlled and Nonequilibrium Assembly of Block Copolymers in Solution. J Am Chem Soc 2024; 146:18781-18796. [PMID: 38967256 PMCID: PMC11258791 DOI: 10.1021/jacs.4c03314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/06/2024]
Abstract
Covalent polymers are versatile macromolecules that have found widespread use in society. Contemporary methods of polymerization have made it possible to construct sequence polymers, including block copolymers, with high precision. Such copolymers assemble in solution when the blocks have differing solubilities. This produces nano- and microparticles of various shapes and sizes. While it is straightforward to draw an analogy between such amphiphilic block copolymers and phospholipids, these two classes of molecules show quite different assembly characteristics. In particular, block copolymers often assemble under kinetic control, thus producing nonequilibrium structures. This leads to a rich variety of behaviors being observed in block copolymer assembly, such as pathway dependence (e.g., thermal history), nonergodicity and responsiveness. The dynamics of polymer assemblies can be readily controlled using changes in environmental conditions and/or integrating functional groups situated on polymers with external chemical reactions. This perspective highlights that kinetic control is both pervasive and a useful attribute in the mechanics of block copolymer assembly. Recent examples are highlighted in order to show that toggling between static and dynamic behavior can be used to generate, manipulate and dismantle nonequilibrium states. New methods to control the kinetics of block copolymer assembly will provide endless unanticipated applications in materials science, biomimicry and medicine.
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Affiliation(s)
- Stephen D. P. Fielden
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United
Kingdom
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2
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Eneh C, Nixon K, Lalwani SM, Sammalkorpi M, Batys P, Lutkenhaus JL. Solid-Liquid-Solution Phases in Poly(diallyldimethylammonium)/Poly(acrylic acid) Polyelectrolyte Complexes at Varying Temperatures. Macromolecules 2024; 57:2363-2375. [PMID: 38495383 PMCID: PMC10938883 DOI: 10.1021/acs.macromol.4c00258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 02/06/2024] [Indexed: 03/19/2024]
Abstract
The coacervation and complexation of oppositely charged polyelectrolytes are dependent on numerous environmental and preparatory factors, but temperature is often overlooked. Temperature effects remain unclear because the temperature dependence of both the dielectric constant and polymer-solvent interaction parameter can yield lower and/or upper critical solution phase behaviors for PECs. Further, secondary interactions, such as hydrogen bonding, can affect the temperature response of a PEC. That is, mixtures of oppositely charged polyelectrolytes can exhibit phase separation upon lowering and/or increasing the mixture's temperature. Here, the phase behavior of poly(diallylmethylammonium)/poly(acrylic acid) (PDADMA/PAA) complexes under varying KBr ionic strengths, mixing ratios, and temperatures at a fixed pH (in which PAA hydrogen bonding can occur) is examined. At room temperature, the PDADMA/PAA PECs exhibit four different phase states: precipitate, coexisting precipitate and coacervate, solid-like gel, and coacervate. Variable-temperature optical microscopy reveals the upper critical solution temperature (UCST) at which each phase transitioned to a solution state. Interestingly, the UCST value is highly dependent on the original phase of the PEC, in which solid-like precipitates exhibit higher UCST values. Large-scale all-atom molecular dynamics (MD) simulations support that precipitates exhibit kinetic trapping, which may contribute to the higher UCST values observed in the experiment. Taken together, this study highlights the significance of temperature on the phase behavior of PECs, which may play a larger role in stimuli-responsive materials, membraneless organelles, and separations applications.
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Affiliation(s)
- Chikaodinaka
I. Eneh
- Artie
McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Kevin Nixon
- Artie
McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Suvesh Manoj Lalwani
- Artie
McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Maria Sammalkorpi
- Department
of Chemistry and Materials Science, Aalto
University, P.O. Box 16100, Aalto 00076, Finland
- Department
of Bioproducts and Biosystems, Aalto University, P.O. Box 16100, Aalto 00076, Finland
- Academy
of Finland Center of Excellence in Life-Inspired Hybrid Materials
(LIBER), Aalto University, P.O. Box 16100, Aalto 00076, Finland
| | - Piotr Batys
- Jerzy
Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, Krakow 30-239, Poland
| | - Jodie L. Lutkenhaus
- Artie
McFerrin Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
- Department
of Materials Science and Engineering, Texas
A&M University, College Station, Texas 77840, United States
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3
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Heo TY, Choi SH. Ionic Strength-Dependent Structure of Complex Coacervate Core Micelles. J Phys Chem B 2024; 128:1256-1265. [PMID: 38288748 DOI: 10.1021/acs.jpcb.3c06004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Salt concentration-dependent structure of complex coacervate core micelles (C3Ms), formed by polyether-based block copolyelectrolytes containing cationic ammonium (A) or anionic sulfonate (S) groups in aqueous media, is investigated by light scattering and small-angle X-ray/neutron scattering (SAX/NS). As the salt concentration increases, both a core radius (Rcore) and an aggregation number (Nagg) significantly decrease, but a corona thickness (Lcorona) is nearly unchanged. Larger salt concentrations can lower the interfacial tension between the coacervate cores and aqueous media, resulting in an increased interfacial area per chain and a more relaxed conformation of the core blocks. Based on the structure characterization, the scaling relationship between structure parameters (i.e., Rcore, Nagg, and Lcorona) and salt concentration is obtained and compared to the theoretical description estimated by the free energy balance between the entropic penalty of core stretching and the interfacial energy. We propose that the free energy contribution of the core block stretching is not negligible in C3Ms because of the highly swollen cores caused by water.
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Affiliation(s)
- Tae-Young Heo
- Department of Chemical Engineering, Hongik University, Seoul 04066, Republic of Korea
| | - Soo-Hyung Choi
- Department of Chemical Engineering, Hongik University, Seoul 04066, Republic of Korea
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4
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Sabadini JB, Oliveira CLP, Loh W. Assessing the Structure and Equilibrium Conditions of Complex Coacervate Core Micelles by Varying Their Shell Composition and Medium Ionic Strength. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:2015-2027. [PMID: 38240211 DOI: 10.1021/acs.langmuir.3c01606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
Complex coacervates result from an associative phase separation commonly involving oppositely charged polyelectrolytes. When this associative interaction occurs between charged-neutral diblock copolymers and oppositely charged homopolymers, a nanometric aggregate called a complex coacervate core micelle, C3M, is formed. Recent studies have addressed the issue of their thermodynamic or kinetic stability but without a clear consensus. To further investigate this issue, we have studied C3Ms formed by the combination of poly(diallyldimethylammonium) and copolymer poly(acrylamide)-b-poly(acrylate) using different preparation protocols. Dynamic light scattering and small-angle X-ray scattering measurements suggest that these structures are in an equilibrium condition because the aggregates do not vary with different preparation protocols or upon aging. In addition, their stability and structures are critically dependent on several parameters such as the density of neutral blocks in their shell and the ionic strength of the medium. Decreasing the amount of copolymer in the system and, hence, the density of neutral blocks in the shell results in an increase in the aggregate size because of the core growth, although their globular shape is retained. On the other hand, larger clusters of micelles were formed at higher ionic strengths. Partially replacing 77% of the copolymer with a homopolymer of the same charge or increasing the ionic strength of the system (above 100 mmol L-1 NaCl) leads to a metastable state, after which phase separation is eventually observed. SAXS analyses reveal that this phase separation above a certain salt concentration occurs due to the coagulation of individual micelles that seem to retain their individual globular structures. Overall, these results confirm earlier claims that equilibrium C3Ms are achieved close to 1:1 charge stoichiometry but also reveal that these conditions may vary at different shell densities or higher ionic strengths, which constitute vital information for envisioning future applications of C3Ms.
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Affiliation(s)
- Júlia Bonesso Sabadini
- Institute of Chemistry, University of Campinas (UNICAMP), P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil
| | | | - Watson Loh
- Institute of Chemistry, University of Campinas (UNICAMP), P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil
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5
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Sinha NJ, Cunha KC, Murphy R, Hawker CJ, Shea JE, Helgeson ME. Competition between β-Sheet and Coacervate Domains Yields Diverse Morphologies in Mixtures of Oppositely Charged Homochiral Polypeptides. Biomacromolecules 2023; 24:3580-3588. [PMID: 37486022 DOI: 10.1021/acs.biomac.3c00361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Biomolecular assembly processes involving competition between specific intermolecular interactions and thermodynamic phase instability have been implicated in a number of pathological states and technological applications of biomaterials. As a model for such processes, aqueous mixtures of oppositely charged homochiral polypeptides such as poly-l-lysine and poly-l-glutamic acid have been reported to form either β-sheet-rich solid-like precipitates or liquid-like coacervate droplets depending on competing hydrogen bonding interactions. Herein, we report studies of polypeptide mixtures that reveal unexpectedly diverse morphologies ranging from partially coalescing and aggregated droplets to bulk precipitates, as well as a previously unreported re-entrant liquid-liquid phase separation at high polypeptide concentration and ionic strength. Combining our experimental results with all-atom molecular dynamics simulations of folded polypeptide complexes reveals a concentration dependence of β-sheet-rich secondary structure, whose relative composition correlates with the observed macroscale morphologies of the mixtures. These results elucidate a crucial balance of interactions that are important for controlling morphology during coacervation in these and potentially similar biologically relevant systems.
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Affiliation(s)
- Nairiti J Sinha
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Materials Department and Materials Research Laboratory, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Keila Cristina Cunha
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Robert Murphy
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Craig J Hawker
- Materials Department and Materials Research Laboratory, University of California Santa Barbara, Santa Barbara, California 93106, United States
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Matthew E Helgeson
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
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6
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García-Jiménez A, Román-Guerrero A, Pérez-Alonso C, Fouconnier B. Liquid-liquid and liquid-solid separation in self-assembled chitosan-alginate and chitosan-pectin complexes. Int J Biol Macromol 2022; 223:1368-1380. [PMID: 36395941 DOI: 10.1016/j.ijbiomac.2022.11.091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/14/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022]
Abstract
The complexation between two oppositely charged polyelectrolytes (PE) can lead liquid-liquid (complex coacervates, CC) or liquid-solid (solid precipitates, SP) phase separations. Herein, the effect of pH (2-11) and ionic strength (I, 0.05-1.0 M KCl) on the associative interactions between chitosan (QL)-alginate (SA) and QL-Pectin (Pec), polysaccharides widely used in biotechnology field, is described. pH and I, exhibited significant effect on the structure and phase transitions by modifying the ionization degree (α), pka, and associative interactions between PE. Onset of binding was established at pHc 9, while continued acidification (pHτ 5.8) led to simultaneous CC and SP exhibiting a maximum turbidity in both systems. At pHδ 4.0, QL-Pec showed preferably CC structures whereas QL-SA maintained the CC and SP structures. At pHω 2, the associative interactions were suppressed due to the low ionization of Pec and SA. I (1.0 M) significantly diminished the interactions in QL-Pec due to charge screening. Molecular weight, second virial coefficient, hydrodynamic size, ionizable groups, and persistence length of polyion, influenced on the phase behavior of QL-Pec and QL-SA systems. Therefore, CC and SP are found simultaneously in both systems, their transitions can be modulated by intrinsic and environmental conditions, expanding the functional properties of complexed polysaccharides.
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Affiliation(s)
- Abraham García-Jiménez
- Departamento de Biotecnología, Universidad Autónoma Metropolitana Unidad Iztapalapa, Av. Ferrocarril de San Rafael Atlixco, 186, Col. Leyes de Reforma 1ª secc., C.P. 09340 Mexico City, Mexico
| | - Angélica Román-Guerrero
- Departamento de Biotecnología, Universidad Autónoma Metropolitana Unidad Iztapalapa, Av. Ferrocarril de San Rafael Atlixco, 186, Col. Leyes de Reforma 1ª secc., C.P. 09340 Mexico City, Mexico.
| | - César Pérez-Alonso
- Departamento de Ingeniería Química, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón esq. Paseo Tollocan s/n, Residencial Colón, C.P. 50120 Toluca, State of Mexico, Mexico
| | - Benoit Fouconnier
- Facultad de Ciencias Químicas, Universidad Veracruzana, Av. Universidad Veracruzana Km. 7.5, Col. Santa Isabel, C.P. 96538 Coatzacoalcos, Veracruz, Mexico
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7
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Sproncken CM, Gumí-Audenis B, Foroutanparsa S, Magana JR, Voets IK. Controlling the Formation of Polyelectrolyte Complex Nanoparticles Using Programmable pH Reactions. Macromolecules 2022; 56:226-233. [PMID: 36644553 PMCID: PMC9835975 DOI: 10.1021/acs.macromol.2c01431] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/28/2022] [Indexed: 12/23/2022]
Abstract
Enabling complexation of weak polyelectrolytes, in the presence of a programmable pH-modulation, offers a means to achieve temporal control over polyelectrolyte coassembly. Here, by mixing oppositely charged poly(allylamine hydrochloride) and poly(sodium methacrylate) in a (bi)sulfite buffer, nanoscopic complex coacervates are formed. Addition of formaldehyde initiates the formaldehyde-sulfite clock reaction, affecting the polyelectrolyte assembly in two ways. First, the abrupt pH increase from the reaction changes the charge density of the polyelectrolytes and thus the ratio of cationic and anionic species. Simultaneously, reactions between the polyamine and formaldehyde lead to chemical modifications on the polymer. Interestingly, core-shell polymeric nanoparticles are produced, which remain colloidally stable for months. Contrastingly, in the same system, in the absence of the clock reaction, aggregation and phase separation occur within minutes to days after mixing. Introducing an acid-producing reaction enables further temporal control over the coassembly, generating transient nanoparticles with nanoscopic dimensions and an adjustable lifetime of tens of minutes.
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8
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Quadrado RF, Fajardo AR. Vapor-induced polyelectrolyte complexation of chitosan/pectin: A promising strategy for the preparation of hydrogels for controlled drug delivery. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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9
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Pugsley CE, Isaac RE, Warren NJ, Behra JS, Cappelle K, Dominguez-Espinosa R, Cayre OJ. Protection of Double-Stranded RNA via Complexation with Double Hydrophilic Block Copolymers: Influence of Neutral Block Length in Biologically Relevant Environments. Biomacromolecules 2022; 23:2362-2373. [PMID: 35549247 PMCID: PMC9198985 DOI: 10.1021/acs.biomac.2c00136] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/03/2022] [Indexed: 12/24/2022]
Abstract
Interaction between the anionic phosphodiester backbone of DNA/RNA and polycations can be exploited as a means of delivering genetic material for therapeutic and agrochemical applications. In this work, quaternized poly(2-(dimethylamino)ethyl methacrylate)-block-poly(N,N-dimethylacrylamide) (PQDMAEMA-b-PDMAm) double hydrophilic block copolymers (DHBCs) were synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization as nonviral delivery vehicles for double-stranded RNA. The assembly of DHBCs and dsRNA forms distinct polyplexes that were thoroughly characterized to establish a relationship between the length of the uncharged poly(N,N-dimethylacrylamide) (PDMA) block and the polyplex size, complexation efficiency, and colloidal stability. Dynamic light scattering reveals the formation of smaller polyplexes with increasing PDMA lengths, while gel electrophoresis confirms that these polyplexes require higher N/P ratio for full complexation. DHBC polyplexes exhibit enhanced stability in low ionic strength environments in comparison to homopolymer-based polyplexes. In vitro enzymatic degradation assays demonstrate that both homopolymer and DHBC polymers efficiently protect dsRNA from degradation by RNase A enzyme.
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Affiliation(s)
- Charlotte E. Pugsley
- School
of Chemical and Process Engineering, University
of Leeds, Leeds LS2 9JT, United Kingdom
- School
of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - R. Elwyn Isaac
- School
of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Nicholas. J. Warren
- School
of Chemical and Process Engineering, University
of Leeds, Leeds LS2 9JT, United Kingdom
| | - Juliette S. Behra
- School
of Chemical and Process Engineering, University
of Leeds, Leeds LS2 9JT, United Kingdom
| | - Kaat Cappelle
- Syngenta
Ghent Innovation Center, Technologiepark 30, B-9052 Gent-Zwijnaarde, Belgium
| | - Rosa Dominguez-Espinosa
- Syngenta
Jealott’s Hill International Research Centre, Bracknell, Berkshire RG42
6EY, England
| | - Olivier. J. Cayre
- School
of Chemical and Process Engineering, University
of Leeds, Leeds LS2 9JT, United Kingdom
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10
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Mehan S, Herrmann L, Chapel JP, Jestin J, Berret JF, Cousin F. The desalting/salting pathway: a route to form metastable aggregates with tuneable morphologies and lifetimes. SOFT MATTER 2021; 17:8496-8505. [PMID: 34474458 DOI: 10.1039/d1sm00260k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigate the formation/re-dissociation mechanisms of hybrid complexes made from negatively charged PAA2k coated γ-Fe2O3 nanoparticles (NP) and positively charged polycations (PDADMAC) in aqueous solution in the regime of very high ionic strength (I). When the building blocks are mixed at large ionic strength (1 M NH4Cl), the electrostatic interaction is screened and complexation does not occur. If the ionic strength is then lowered down to a targeted ionic strength Itarget, there is a critical threshold Ic = 0.62 M at which complexation occurs, that is independent of the charge ratio Z and the pathway used to reduce salinity (drop-by-drop mixing or fast mixing). If salt is added back up to 1 M, the transition is not reversible and persistent out-of-equilibrium aggregates are formed. The lifetimes of such aggregates depends on Itarget: the closer Itarget to Ic is, the more difficult it is to dissolve the aggregates. Such peculiar behavior is driven by the inner structure of the complexes that are formed after desalting. When Itarget is far below Ic, strong electrostatic interactions induce the formation of dense, compact and frozen aggregates. Such aggregates can only poorly reorganize further on with time, which makes their dissolution upon resalting almost reversible. Conversely, when Itarget is close to Ic more open aggregates are formed due to weaker electrostatic interactions upon desalting. The system can thus rearrange with time to lower its free energy and reach more stable out-of-equilibrium states which are very difficult to dissociate back upon resalting, even at very high ionic strength.
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Affiliation(s)
- Sumit Mehan
- Laboratoire Léon Brillouin, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette Cedex, France.
| | - Laure Herrmann
- Université de Paris, CNRS, Matière et systèmes complexes, 75013 Paris, France
| | - Jean-Paul Chapel
- Centre de Recherche Paul Pascal (CRPP), UMR CNRS 5031, Université de Bordeaux, 33600 Pessac, France
| | - Jacques Jestin
- Laboratoire Léon Brillouin, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette Cedex, France.
| | | | - Fabrice Cousin
- Laboratoire Léon Brillouin, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette Cedex, France.
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11
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Masella M, Crudu A, Léonforté F. Hybrid polarizable simulations of a conventional hydrophobic polyelectrolyte. Toward a theoretical tool for green science innovation. J Chem Phys 2021; 155:114903. [PMID: 34551548 DOI: 10.1063/5.0056508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hybrid modeling approaches based on all-atom force fields to handle a solute and coarse-grained models to account for the solvent are promising numerical tools that can be used to understand the properties of large and multi-components solutions and thus to speed up the development of new industrial products that obey the standard of green and sustainable chemistry. Here, we discuss the ability of a full polarizable hybrid approach coupled to a standard molecular dynamics scheme to model the behavior in the aqueous phase and at infinite dilution conditions of a standard hydrophobic polyelectrolyte polymer whose charge is neutralized by explicit counterions. Beyond the standard picture of a polyelectrolyte behavior governed by an interplay between opposite intra-polyelectrolyte and inter-polyelectrolyte/counterion Coulombic effects, our simulations show the key role played by both intra-solute polarization effects and long range solute/solvent electrostatics to stabilize compact globular conformations of that polyelectrolyte. Our full polarizable hybrid modeling approach is thus a new theoretical tool well suited to be used in digital strategies for accelerating innovation for green science, for instance.
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Affiliation(s)
- Michel Masella
- Laboratoire de Biologie Structurale et Radiobiologie, Service de Bioénergétique, Biologie Structurale et Mécanismes, Institut Joliot, CEA Saclay, F-91191 Gif sur Yvette Cedex, France
| | - Alina Crudu
- L'Oréal Research and Innovation, Aulnay-Sous-Bois, France
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12
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Lee M, Perry SL, Hayward RC. Complex Coacervation of Polymerized Ionic Liquids in Non-aqueous Solvents. ACS POLYMERS AU 2021; 1:100-106. [PMID: 36855425 PMCID: PMC9954202 DOI: 10.1021/acspolymersau.1c00017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Oppositely charged polymerized ionic liquids (PILs) were used to form complex coacervates in two different organic solvents, 2,2,2-trifluoroethanol (TFE) and hexafluoro-2-propanol (HFIP), and the corresponding phase diagrams were constructed using UV-vis, NMR, and turbidity experiments. While previous studies on complex coacervates have focused almost exclusively on aqueous environments, the use of PILs in the current work enabled studies in solvents with substantially lower dielectric constants (27.0 for TFE, 16.7 for HFIP). The critical salt concentration required to induce complete miscibility was roughly 2-fold larger in HFIP compared with TFE, and two different PIL complexes, solidlike precipitates and liquidlike coacervates, were found in both systems. This study provides insight into the effects of low-dielectric-constant solvents on complex coacervation, which has not been widely studied because of the limited solubility of conventional polyelectrolytes in these media.
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Affiliation(s)
- Minjung Lee
- Department
of Polymer Science and Engineering, University
of Massachusetts, Amherst, 120 Governors Drive, Amherst, Massachusetts 01003-9263, United States
| | - Sarah L. Perry
- Department
of Chemical Engineering, University of Massachusetts,
Amherst, 686 North Pleasant
Street, Amherst, Massachusetts 01003-9303, United States
| | - Ryan C. Hayward
- Department
of Polymer Science and Engineering, University
of Massachusetts, Amherst, 120 Governors Drive, Amherst, Massachusetts 01003-9263, United States,Department
of Chemical and Biological Engineering, University of Colorado Boulder, 596
UCB, Boulder, Colorado 80309, United States,
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13
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Marras AE, Ting JM, Stevens KC, Tirrell MV. Advances in the Structural Design of Polyelectrolyte Complex Micelles. J Phys Chem B 2021; 125:7076-7089. [PMID: 34160221 PMCID: PMC9282648 DOI: 10.1021/acs.jpcb.1c01258] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Polyelectrolyte complex micelles (PCMs) are a unique class of self-assembled nanoparticles that form with a core of associated polycations and polyanions, microphase-separated from neutral, hydrophilic coronas in aqueous solution. The hydrated nature and structural and chemical versatility make PCMs an attractive system for delivery and for fundamental polymer physics research. By leveraging block copolymer design with controlled self-assembly, fundamental structure-property relationships can be established to tune the size, morphology, and stability of PCMs precisely in pursuit of tailored nanocarriers, ultimately offering storage, protection, transport, and delivery of active ingredients. This perspective highlights recent advances in predictive PCM design, focusing on (i) structure-property relationships to target specific nanoscale dimensions and shapes and (ii) characterization of PCM dynamics primarily using time-resolved scattering techniques. We present several vignettes from these two emerging areas of PCM research and discuss key opportunities for PCM design to advance precision medicine.
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Affiliation(s)
- Alexander E Marras
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Jeffrey M Ting
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Kaden C Stevens
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Matthew V Tirrell
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
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14
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Marras AE, Campagna TR, Vieregg JR, Tirrell MV. Physical Property Scaling Relationships for Polyelectrolyte Complex Micelles. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00743] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Alexander E. Marras
- Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Trinity R. Campagna
- Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Jeffrey R. Vieregg
- Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Matthew V. Tirrell
- Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637, United States
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15
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Sproncken CM, Magana JR, Voets IK. 100th Anniversary of Macromolecular Science Viewpoint: Attractive Soft Matter: Association Kinetics, Dynamics, and Pathway Complexity in Electrostatically Coassembled Micelles. ACS Macro Lett 2021; 10:167-179. [PMID: 33628618 PMCID: PMC7894791 DOI: 10.1021/acsmacrolett.0c00787] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 01/05/2021] [Indexed: 02/07/2023]
Abstract
Electrostatically coassembled micelles constitute a versatile class of functional soft materials with broad application potential as, for example, encapsulation agents for nanomedicine and nanoreactors for gels and inorganic particles. The nanostructures that form upon the mixing of selected oppositely charged (block co)polymers and other ionic species greatly depend on the chemical structure and physicochemical properties of the micellar building blocks, such as charge density, block length (ratio), and hydrophobicity. Nearly three decades of research since the introduction of this new class of polymer micelles shed significant light on the structure and properties of the steady-state association colloids. Dynamics and out-of-equilibrium processes, such as (dis)assembly pathways, exchange kinetics of the micellar constituents, and reaction-assembly networks, have steadily gained more attention. We foresee that the broadened scope will contribute toward the design and preparation of otherwise unattainable structures with emergent functionalities and properties. This Viewpoint focuses on current efforts to study such dynamic and out-of-equilibrium processes with greater spatiotemporal detail. We highlight different approaches and discuss how they reveal and rationalize similarities and differences in the behavior of mixed micelles prepared under various conditions and from different polymeric building blocks.
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Affiliation(s)
- Christian
C. M. Sproncken
- Laboratory of Self-Organizing
Soft Matter, Department of Chemical Engineering and Chemistry and
Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600 MB, Eindhoven, The Netherlands
| | - J. Rodrigo Magana
- Laboratory of Self-Organizing
Soft Matter, Department of Chemical Engineering and Chemistry and
Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Ilja K. Voets
- Laboratory of Self-Organizing
Soft Matter, Department of Chemical Engineering and Chemistry and
Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600 MB, Eindhoven, The Netherlands
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16
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Bos I, Timmerman M, Sprakel J. FRET-Based Determination of the Exchange Dynamics of Complex Coacervate Core Micelles. Macromolecules 2021; 54:398-411. [PMID: 33456072 PMCID: PMC7808214 DOI: 10.1021/acs.macromol.0c02387] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 12/08/2020] [Indexed: 02/07/2023]
Abstract
Complex coacervate core micelles (C3Ms) are nanoscopic structures formed by charge interactions between oppositely charged macroions and used to encapsulate a wide variety of charged (bio)molecules. In most cases, C3Ms are in a dynamic equilibrium with their surroundings. Understanding the dynamics of molecular exchange reactions is essential as this determines the rate at which their cargo is exposed to the environment. Here, we study the molecular exchange in C3Ms by making use of Förster resonance energy transfer (FRET) and derive an analytical model to relate the experimentally observed increase in FRET efficiency to the underlying macromolecular exchange rates. We show that equilibrated C3Ms have a broad distribution of exchange rates. The overall exchange rate can be strongly increased by increasing the salt concentration. In contrast, changing the unlabeled homopolymer length does not affect the exchange of the labeled homopolymers and an increase in the micelle concentration only affects the FRET increase rate at low micelle concentrations. Together, these results suggest that the exchange of these equilibrated C3Ms occurs mainly by expulsion and insertion, where the rate-limiting step is the breaking of ionic bonds to expel the chains from the core. These are important insights to further improve the encapsulation efficiency of C3Ms.
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Affiliation(s)
- Inge Bos
- Physical Chemistry and Soft
Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Marga Timmerman
- Physical Chemistry and Soft
Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Joris Sprakel
- Physical Chemistry and Soft
Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
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17
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Timmers EM, Magana JR, Schoenmakers SMC, Fransen PM, Janssen HM, Voets IK. Sequence of Polyurethane Ionomers Determinative for Core Structure of Surfactant-Copolymer Complexes. Int J Mol Sci 2020; 22:E337. [PMID: 33396960 PMCID: PMC7795199 DOI: 10.3390/ijms22010337] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/20/2020] [Accepted: 12/23/2020] [Indexed: 01/04/2023] Open
Abstract
The core of micelles self-assembled from amphiphiles is hydrophobic and contains little water, whereas complex coacervate core micelles co-assembled from oppositely charged hydrophilic polymers have a hydrophilic core with a high water content. Co-assembly of ionic surfactants with ionic-neutral copolymers yields surfactant-copolymer complexes known to be capable of solubilizing both hydrophilic and hydrophobic cargo within the mixed core composed of a coacervate phase with polyelectrolyte-decorated surfactant micelles. Here we formed such complexes from asymmetric (PUI-A2) and symmetric (PUI-S2), sequence-controlled polyurethane ionomers and poly(N-methyl-2-vinylpyridinium iodide)29-b-poly(ethylene oxide)204 copolymers. The complexes with PUI-S2 were 1.3-fold larger in mass and 1.8-fold larger in radius of gyration than the PUI-A2 complexes. Small-angle X-ray scattering revealed differences in the packing of the similarly sized PUI micelles within the core of the complexes. The PUI-A2 micelles were arranged in a more ordered fashion and were spaced further apart from each other (10 nm vs. 6 nm) than the PUI-S2 micelles. Hence, this work shows that the monomer sequence of amphiphiles can be varied to alter the internal structure of surfactant-copolymer complexes. Since the structure of the micellar core may affect both the cargo loading and release, our findings suggest that these properties may be tuned through control of the monomer sequence of the micellar constituents.
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Affiliation(s)
- Elizabeth M. Timmers
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (E.M.T.); (J.R.M.)
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Jose Rodrigo Magana
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (E.M.T.); (J.R.M.)
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Sandra M. C. Schoenmakers
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - P. Michel Fransen
- SyMO-Chem B.V., Den Dolech 2, 5612 AZ Eindhoven, The Netherlands; (P.M.F.); (H.M.J.)
| | - Henk M. Janssen
- SyMO-Chem B.V., Den Dolech 2, 5612 AZ Eindhoven, The Netherlands; (P.M.F.); (H.M.J.)
| | - Ilja K. Voets
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (E.M.T.); (J.R.M.)
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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18
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Wu H, Ting JM, Yu B, Jackson NE, Meng S, de Pablo JJ, Tirrell MV. Spatiotemporal Formation and Growth Kinetics of Polyelectrolyte Complex Micelles with Millisecond Resolution. ACS Macro Lett 2020; 9:1674-1680. [PMID: 35617069 DOI: 10.1021/acsmacrolett.0c00543] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
We have directly observed the in situ self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. A synthesized neutral-charged diblock polycation and homopolyanion that we have previously investigated as a model charge-matched, core-shell micelle system were selected for this work. The initial micellization of the oppositely charged polyelectrolytes was completed within the dead time of mixing of 100 ms, followed by micelle growth and equilibration up to several seconds. By combining the structural evolution of the radius of gyration (Rg) with complementary molecular dynamics simulations, we show how the self-assemblies evolve incrementally in size over time through a two-step kinetic process: first, oppositely charged polyelectrolyte chains pair to form nascent aggregates that immediately assemble into spherical micelles, and second, these PEC micelles grow into larger micellar entities. This work has determined one possible kinetic pathway for the initial formation of PEC micelles, which provides useful physical insights for increasing fundamental understanding self-assembly dynamics, driven by polyelectrolyte complexation that occurs on ultrafast time scales.
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Affiliation(s)
- Hao Wu
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Jeffrey M. Ting
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Boyuan Yu
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Nicholas E. Jackson
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Siqi Meng
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Juan J. de Pablo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Matthew V. Tirrell
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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19
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SAXS methods for investigating macromolecular and self-assembled polyelectrolyte complexes. Methods Enzymol 2020; 646:223-259. [PMID: 33453927 DOI: 10.1016/bs.mie.2020.09.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Polyelectrolyte complexation is driven by associative interactions between oppositely charged polyelectrolytes, resulting in formation of a macroscopic polymer dense phase and a polymer dilute phase with applications in coatings, adhesives, and purification membranes. Beyond macroscale phase separation, precision polymer synthesis has enabled further development of polyelectrolyte complex (PEC)-based self-assembled micelles and hydrogels with applications in biotechnology. Interestingly, it has been suggested that mechanisms similar to polyelectrolyte complexation drive formation of biological condensates that play an indispensable role in cellular biogenesis. The formation pathways and functionality of these complex materials is dependent on the physical properties that are built into polymer structure and the resulting physical conformation in the dilute and dense phase. Scattering techniques have enabled in situ investigation of structure-function relationships in PEC materials that may address unresolved biophysical questions in cellular processes as well as catalyze the development of novel materials for diverse applications. We describe preparation of PEC materials with controlled polymer characteristics (length, blockiness, charge density), small-angle X-ray scattering (SAXS) techniques employed to probe appropriate length scales, and the data analysis routines from a practical standpoint for new users. This article deals with bulk complexes and not with the related, important and interesting area of non-equilibrium layer-by-layer assembly of polyelectrolytes.
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20
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Li L, Srivastava S, Meng S, Ting JM, Tirrell MV. Effects of Non-Electrostatic Intermolecular Interactions on the Phase Behavior of pH-Sensitive Polyelectrolyte Complexes. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00999] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Lu Li
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Samanvaya Srivastava
- Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Siqi Meng
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Jeffrey M. Ting
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Matthew V. Tirrell
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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21
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Meng S, Ting JM, Wu H, Tirrell MV. Solid-to-Liquid Phase Transition in Polyelectrolyte Complexes. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00930] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Siqi Meng
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Jeffrey M. Ting
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Hao Wu
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Matthew V. Tirrell
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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22
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Ting JM, Marras AE, Mitchell JD, Campagna TR, Tirrell MV. Comparing Zwitterionic and PEG Exteriors of Polyelectrolyte Complex Micelles. Molecules 2020; 25:E2553. [PMID: 32486282 PMCID: PMC7321349 DOI: 10.3390/molecules25112553] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/26/2020] [Accepted: 05/27/2020] [Indexed: 12/12/2022] Open
Abstract
A series of model polyelectrolyte complex micelles (PCMs) was prepared to investigate the consequences of neutral and zwitterionic chemistries and distinct charged cores on the size and stability of nanocarriers. Using aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization, we synthesized a well-defined diblock polyelectrolyte system, poly(2-methacryloyloxyethyl phosphorylcholine methacrylate)-block-poly((vinylbenzyl) trimethylammonium) (PMPC-PVBTMA), at various neutral and charged block lengths to compare directly against PCM structure-property relationships centered on poly(ethylene glycol)-block-poly((vinylbenzyl) trimethylammonium) (PEG-PVBTMA) and poly(ethylene glycol)-block-poly(l-lysine) (PEG-PLK). After complexation with a common polyanion, poly(sodium acrylate), the resulting PCMs were characterized by dynamic light scattering (DLS) and small angle X-ray scattering (SAXS). We observed uniform assemblies of spherical micelles with a diameter ~1.5-2× larger when PMPC-PVBTMA was used compared to PEG-PLK and PEG-PVBTMA via SAXS and DLS. In addition, PEG-PLK PCMs proved most resistant to dissolution by both monovalent and divalent salt, followed by PEG-PVBTMA then PMPC-PVBTMA. All micelle systems were serum stable in 100% fetal bovine serum over the course of 8 h by time-resolved DLS, demonstrating minimal interactions with serum proteins and potential as in vivo drug delivery vehicles. This thorough study of the synthesis, assembly, and characterization of zwitterionic polymers in PCMs advances the design space for charge-driven micelle assemblies.
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Affiliation(s)
- Jeffrey M. Ting
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA; (J.M.T.); (A.E.M.); (J.D.M.); (T.R.C.)
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Alexander E. Marras
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA; (J.M.T.); (A.E.M.); (J.D.M.); (T.R.C.)
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Joseph D. Mitchell
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA; (J.M.T.); (A.E.M.); (J.D.M.); (T.R.C.)
| | - Trinity R. Campagna
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA; (J.M.T.); (A.E.M.); (J.D.M.); (T.R.C.)
| | - Matthew V. Tirrell
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA; (J.M.T.); (A.E.M.); (J.D.M.); (T.R.C.)
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, IL 60439, USA
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23
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Abstract
AbstractStrongly interacting polyelectrolyte complexes (PECs) are a versatile class of materials whose physical states can be driven from solids into liquids and ultimately into homogenous solution upon salt addition. However, many of these materials can display high stability using common monovalent salts, leading to difficulties in accessing the entire PEC spectrum. Here, the model system, composed of two styrenic polyelectrolytes, required exceptionally high salt to drive phase transition. We term the amount of salt required to drive these transitions salt resistance. In water, the PEC transferred from solid into liquid at 2.5 M NaBr and never fully dissociated within the studied salt range. We discovered an unconventional approach of weakening salt resistance by switching the solvent to miscible ethylene glycol/water and ethanol/water, allowing us to systematically introduce more hydrophobic constituents. Employing microscopy to determine physical states qualitatively, we found that higher hydrophobicity lowered salt resistance for phase transition and disassembly.
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24
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Sing CE. Micro- to macro-phase separation transition in sequence-defined coacervates. J Chem Phys 2020; 152:024902. [DOI: 10.1063/1.5140756] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- Charles E. Sing
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, Illinois 61801, USA
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25
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Wu H, Ting JM, Tirrell MV. Mechanism of Dissociation Kinetics in Polyelectrolyte Complex Micelles. Macromolecules 2020. [DOI: 10.1021/acs.macromol.9b01814] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Hao Wu
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
| | - Jeffrey M. Ting
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
- Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Matthew V. Tirrell
- Pritzker School of Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States
- Argonne National Laboratory, Lemont, Illinois 60439, United States
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26
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Potaufeux JE, Odent J, Notta-Cuvier D, Lauro F, Raquez JM. A comprehensive review of the structures and properties of ionic polymeric materials. Polym Chem 2020. [DOI: 10.1039/d0py00770f] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This review focuses on the mechanistic approach, the structure–property relationship and applications of ionic polymeric materials.
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Affiliation(s)
- Jean-Emile Potaufeux
- Laboratory of Polymeric and Composite Materials (LPCM)
- Center of Innovation and Research in Materials and Polymers (CIRMAP)
- University of Mons (UMONS)
- Mons
- Belgium
| | - Jérémy Odent
- Laboratory of Polymeric and Composite Materials (LPCM)
- Center of Innovation and Research in Materials and Polymers (CIRMAP)
- University of Mons (UMONS)
- Mons
- Belgium
| | - Delphine Notta-Cuvier
- Laboratory of Industrial and Human Automatic Control and Mechanical Engineering (LAMIH)
- UMR CNRS 8201
- University Polytechnique Hauts-De-France (UPHF)
- Le Mont Houy
- France
| | - Franck Lauro
- Laboratory of Industrial and Human Automatic Control and Mechanical Engineering (LAMIH)
- UMR CNRS 8201
- University Polytechnique Hauts-De-France (UPHF)
- Le Mont Houy
- France
| | - Jean-Marie Raquez
- Laboratory of Polymeric and Composite Materials (LPCM)
- Center of Innovation and Research in Materials and Polymers (CIRMAP)
- University of Mons (UMONS)
- Mons
- Belgium
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27
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Bos I, Sprakel J. Langevin Dynamics Simulations of the Exchange of Complex Coacervate Core Micelles: The Role of Nonelectrostatic Attraction and Polyelectrolyte Length. Macromolecules 2019; 52:8923-8931. [PMID: 31787780 PMCID: PMC6881903 DOI: 10.1021/acs.macromol.9b01442] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/04/2019] [Indexed: 12/12/2022]
Abstract
Complex coacervate core micelles (C3Ms) are promising encapsulators for a wide variety of (bio)molecules. To protect and stabilize their cargo, it is essential to control their exchange dynamics. Yet, to date, little is known about the kinetic stability of C3Ms and the dynamic equilibrium of molecular building blocks with micellar species. Here we study the C3M exchange during the initial micellization by using Langevin dynamics simulations. In this way, we show that charge neutral heterocomplexes consisting of multiple building blocks are the primary mediator for exchange. In addition, we show that the kinetic stability of the C3Ms can be tuned not only by the electrostatic interaction but also by the nonelectrostatic attraction between the polyelectrolytes, the polyelectrolyte length ratio, and the overall polyelectrolyte length. These insights offer new rational design guides to aid the development of new C3M encapsulation strategies.
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Affiliation(s)
- Inge Bos
- Physical Chemistry and Soft
Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Joris Sprakel
- Physical Chemistry and Soft
Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
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28
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Wu H, Ting JM, Weiss TM, Tirrell MV. Interparticle Interactions in Dilute Solutions of Polyelectrolyte Complex Micelles. ACS Macro Lett 2019; 8:819-825. [PMID: 35619501 DOI: 10.1021/acsmacrolett.9b00226] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The application of dilute solutions of polyelectrolyte complex (PEC) micelles for delivering therapeutic nucleic acids into disease sites has gained momentum. This Letter reports a detailed characterization of PEC micelles in dilute solutions including their internal structures and the determination of the interparticle interactions. The polymer concentration ranges from 0.1 to 0.5 wt %, a regime where micelle-micelle interactions are infrequent. We employ synchrotron small-angle X-ray scattering (SAXS) to simultaneously probe the morphology, internal structure, and radius of gyration (Rg) of the self-assemblies formed by charged diblock polyelectrolytes and homopolyelectrolytes. The emerging appearance of the structure factor in SAXS profiles with the increasing polymer concentration demonstrates the presence of the repulsive intermicellar correlations, which is further confirmed by the differences between the "reciprocal Rg" estimated by Guinier approximation and the "real space Rg" determined by pair distribution functions. We find that the soft corona chains tethered on the surface of phase-separated complex domains are compressed when micelles come close to the point where a hard-sphere interaction takes over. These findings contribute to the fundamental understanding of the structure and space-filling constraints in the complexation-driven self-assemblies and advance the rational design of cationic polymer-based nonviral gene delivery vectors.
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Affiliation(s)
- Hao Wu
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Jeffrey M. Ting
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Thomas M. Weiss
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Matthew V. Tirrell
- Institute for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Argonne National Laboratory, Lemont, Illinois 60439, United States
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29
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Ong GMC, Sing CE. Mapping the phase behavior of coacervate-driven self-assembly in diblock copolyelectrolytes. SOFT MATTER 2019; 15:5116-5127. [PMID: 31188388 DOI: 10.1039/c9sm00741e] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Oppositely-charged polymers can undergo an associative phase separation process known as complex coacervation, which is driven by the electrostatic attraction between the two polymer species. This driving force for phase separation can be harnessed to drive self-assembly, via pairs of block copolyelectrolytes with opposite charge and thus favorable coulombic interactions. There are few predictions of coacervate self-assembly phase behavior due to the wide variety of molecular and environmental parameters, along with fundamental theoretical challenges. In this paper, we use recent advances in coacervate theory to predict the solution-phase assembly of diblock polyelectrolyte pairs for a number of molecular design parameters (charged block fraction, polymer length). Phase diagrams show that self-assembly occurs at high polymer, low salt concentrations for a range of charge block fractions. We show that we qualitatively obtain limiting results seen in the experimental literature, including the emergence of a high polymer-fraction reentrant transition that gives rise to a self-compatibilized homopolymer coacervate behavior at the limit of high charge block fraction. In intermediate charge block fractions, we draw an analogy between the role of salt concentration in coacervation-driven assembly and the role of temperature in χ-driven assembly. We also explore salt partitioning between microphase separated domains in block copolyelectrolytes, with parallels to homopolyelectrolyte coacervation.
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Affiliation(s)
- Gary M C Ong
- Department of Chemical and Biomolecular Engineering, 600 S. Mathews Ave., Urbana, IL, USA.
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30
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Marras AE, Vieregg JR, Ting JM, Rubien JD, Tirrell MV. Polyelectrolyte Complexation of Oligonucleotides by Charged Hydrophobic-Neutral Hydrophilic Block Copolymers. Polymers (Basel) 2019; 11:E83. [PMID: 30960067 PMCID: PMC6402004 DOI: 10.3390/polym11010083] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/01/2019] [Accepted: 01/02/2019] [Indexed: 12/12/2022] Open
Abstract
Polyelectrolyte complex micelles (PCMs, core-shell nanoparticles formed by complexation of a polyelectrolyte with a polyelectrolyte-hydrophilic neutral block copolymer) offer a solution to the critical problem of delivering therapeutic nucleic acids, Despite this, few systematic studies have been conducted on how parameters such as polycation charge density, hydrophobicity, and choice of charged group influence PCM properties, despite evidence that these strongly influence the complexation behavior of polyelectrolyte homopolymers. In this article, we report a comparison of oligonucleotide PCMs and polyelectrolyte complexes formed by poly(lysine) and poly((vinylbenzyl) trimethylammonium) (PVBTMA), a styrenic polycation with comparatively higher charge density, increased hydrophobicity, and a permanent positive charge. All of these differences have been individually suggested to provide increased complex stability, but we find that PVBTMA in fact complexes oligonucleotides more weakly than does poly(lysine), as measured by stability versus added salt. Using small angle X-ray scattering and electron microscopy, we find that PCMs formed from both cationic blocks exhibit very similar structure-property relationships, with PCM radius determined by the cationic block size and shape controlled by the hybridization state of the oligonucleotides. These observations narrow the design space for optimizing therapeutic PCMs and provide new insights into the rich polymer physics of polyelectrolyte self-assembly.
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Affiliation(s)
- Alexander E Marras
- Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
| | - Jeffrey R Vieregg
- Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
| | - Jeffrey M Ting
- Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
- Institute for Molecular Engineering at Argonne National Laboratory, Lemont, IL 60439, USA.
| | - Jack D Rubien
- Departments of Biology and Physics, Swarthmore College, Swarthmore, PA 19081, USA.
| | - Matthew V Tirrell
- Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
- Institute for Molecular Engineering at Argonne National Laboratory, Lemont, IL 60439, USA.
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31
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van Hees IA, Swinkels PJM, Fokkink RG, Velders AH, Voets IK, van der Gucht J, Kamperman M. Self-assembly of oppositely charged polyelectrolyte block copolymers containing short thermoresponsive blocks. Polym Chem 2019; 10:3127-3134. [PMID: 34912475 PMCID: PMC8612725 DOI: 10.1039/c9py00250b] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 03/27/2019] [Indexed: 12/12/2022]
Abstract
The assembly of oppositely charged block copolymers, containing small thermoresponsive moieties, was investigated as a function of salt concentration and temperature. Aqueous solutions of poly-[N-isopropylacrylamide]-b-poly[dimethylaminoethyl methacrylate] (NIPAM44-b-DMAEMA216) and PNIPAM-b-poly[acrylic acid]-b-PNIPAM (NIPAM35-b-AA200-b-NIPAM35) were mixed in equal charge stoichiometry, and analysed by light scattering (LS), NMR spectroscopy and small angle X-ray scattering (SAXS). At room temperature, two different micelle morphologies were found at different salt concentrations. At NaCl concentrations below 0.75 M, complex coacervate core micelles (C3M) with a PNIPAM corona were formed as a result of interpolyelectrolyte complexation. At NaCl concentrations exceeding 0.75 M, the C3M micelles inverted into PNIPAM cored micelles (PCM), containing a water soluble polyelectrolyte corona. This behavior is ascribed to the salt concentration dependence of both the lower critical solution temperature (LCST) of PNIPAM, and the complex coacervation. Above 0.75 M NaCl, the PNIPAM blocks are insoluble in water at room temperature, while complexation between the polyelectrolytes is prevented because of charge screening by the salt. Upon increasing the temperature, both types of micelles display a cloud point temperature (Tcp), despite the small thermoresponsive blocks, and aggregate into hydrogels. These hydrogels consist of a complexed polyelectrolyte matrix with microphase separated PNIPAM domains. Controlling the morphology and aggregation of temperature sensitive polyelectrolytes can be an important tool for drug delivery systems, or the application and hardening of underwater glues. The assembly of oppositely charged block copolymers, containing small thermoresponsive moieties, was investigated as a function of salt concentration and temperature.![]()
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Affiliation(s)
- I. A. van Hees
- Physical Chemistry and Soft Matter
- Wageningen University and Research
- 6708 WE Wageningen
- The Netherlands
| | - P. J. M. Swinkels
- Institute of Physics
- University of Amsterdam
- 1098 XH Amsterdam
- the Netherlands
| | - R. G. Fokkink
- Physical Chemistry and Soft Matter
- Wageningen University and Research
- 6708 WE Wageningen
- The Netherlands
| | - A. H. Velders
- Laboratory of BioNanoTechnology
- Wageningen University and Research
- Wageningen
- The Netherlands
| | - I. K. Voets
- Department of Chemical Engineering and Chemistry
- Eindhoven University of Technology
- 5600 MB Eindhoven
- The Netherlands
| | - J. van der Gucht
- Physical Chemistry and Soft Matter
- Wageningen University and Research
- 6708 WE Wageningen
- The Netherlands
| | - M. Kamperman
- Polymer Science
- Zernike Institute for Advanced Materials
- University of Groningen
- 9747 AG Groningen
- The Netherlands
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32
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Ferreira GA, Piculell L, Loh W. Hydration-Dependent Hierarchical Structures in Block Copolymer–Surfactant Complex Salts. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b02053] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Guilherme A. Ferreira
- Institute of Chemistry, University of Campinas (UNICAMP), P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil
| | - Lennart Piculell
- Division of Physical Chemistry, Lund University, P.O. Box 124, S-221 00 Lund, Sweden
| | - Watson Loh
- Institute of Chemistry, University of Campinas (UNICAMP), P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil
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