1
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Truong HP, Saleh OA. Magnetic tweezers characterization of the entropic elasticity of intrinsically disordered proteins and peptoids. Methods Enzymol 2024; 694:209-236. [PMID: 38492952 DOI: 10.1016/bs.mie.2023.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
Understanding the conformational behavior of biopolymers is essential to unlocking knowledge of their biophysical mechanisms and functional roles. Single-molecule force spectroscopy can provide a unique perspective on this by exploiting entropic elasticity to uncover key biopolymer structural parameters. A particularly powerful approach involves the use of magnetic tweezers, which can easily generate lower stretching forces (0.1-20 pN). For forces at the low end of this range, the elastic response of biopolymers is sensitive to excluded volume effects, and they can be described by Pincus blob elasticity model that allow robust extraction of the Flory polymer scaling exponent. Here, we detail protocols for the use of magnetic tweezers for force-extension measurements of intrinsically disordered proteins and peptoids. We also discuss procedures for fitting low-force elastic curves to the predictions of polymer physics models to extract key conformational parameters.
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Affiliation(s)
- Hoang P Truong
- Materials Department, University of California, Santa Barbara, CA, United States
| | - Omar A Saleh
- Materials Department, University of California, Santa Barbara, CA, United States; Biomolecular Sciences and Engineering Program, University of California, Santa Barbara, CA, United States; Physics Department, University of California, Santa Barbara, CA, United States.
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2
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Huo H, Zhao W, Duan X, Sun ZY. Control of Diblock Copolyelectrolyte Morphology through Electric Field Application. Macromolecules 2023. [DOI: 10.1021/acs.macromol.2c01780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Haiyang Huo
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei230026, China
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun130022, China
| | - Wanchen Zhao
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun130022, China
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun130012, China
| | - Xiaozheng Duan
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun130022, China
| | - Zhao-Yan Sun
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei230026, China
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun130022, China
- Xinjiang Laboratory of Phase Transitions and Microstructures in Condensed Matters, College of Physical Science and Technology, Yili Normal University, Yining835000, China
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3
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Ramesh PS, Patra TK. Polymer sequence design via molecular simulation-based active learning. SOFT MATTER 2023; 19:282-294. [PMID: 36519427 DOI: 10.1039/d2sm01193j] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Molecular-scale interactions and chemical structures offer an enormous opportunity to tune material properties. However, designing materials from their molecular scale is a grand challenge owing to the practical limitations in exploring astronomically large design spaces using traditional experimental or computational methods. Advancements in data science and machine learning have produced a host of tools and techniques that can address this problem and facilitate the efficient exploration of large search spaces. In this work, a blended approach integrating physics-based methods, machine learning techniques and uncertainty quantification is implemented to effectively screen a macromolecular sequence space and design target structures. Here, we survey and assess the efficacy of data-driven methods within the framework of active learning for a challenging design problem, viz., sequence optimization of a copolymer. We report the impact of surrogate models, kernels, and initial conditions on the convergence of the active learning method for the sequence design problem. This work establishes optimal strategies and hyperparameters for efficient inverse design of polymer sequences via active learning.
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Affiliation(s)
- Praneeth S Ramesh
- Department of Chemical Engineering, Center for Atomistic Modeling and Materials Design and Center for Carbon Capture Utilization and Storage, Indian Institute of Technology Madras, Chennai, TN 600036, India.
| | - Tarak K Patra
- Department of Chemical Engineering, Center for Atomistic Modeling and Materials Design and Center for Carbon Capture Utilization and Storage, Indian Institute of Technology Madras, Chennai, TN 600036, India.
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4
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Laghmach R, Malhotra I, Potoyan DA. Multiscale Modeling of Protein-RNA Condensation in and Out of Equilibrium. Methods Mol Biol 2023; 2563:117-133. [PMID: 36227470 PMCID: PMC11186142 DOI: 10.1007/978-1-0716-2663-4_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A vast number of intracellular membraneless bodies also known as biomolecular condensates form through a liquid-liquid phase separation (LLPS) of biomolecules. To date, phase separation has been identified as the main driving force for a membraneless organelles such as nucleoli, Cajal bodies, stress granules, and chromatin compartments. Recently, the protein-RNA condensation is receiving increased attention, because it is closely related to the biological function of cells such as transcription, translation, and RNA metabolism. Despite the multidisciplinary efforts put forth to study the biophysical properties of protein-RNA condensates, there are many fundamental unanswered questions regarding the mechanism of formation and regulation of protein-RNA condensates in eukaryotic cells. Major challenges in studying protein-RNA condensation stem from (i) the molecular heterogeneity and conformational flexibility of RNA and protein chains and (ii) the nonequilibrium nature of transcription and cellular environment. Computer simulations, bioinformatics, and mathematical models are uniquely positioned for shedding light on the microscopic nature of protein-RNA phase separation. To this end, there is an urgent need for innovative models with the right spatiotemporal resolution for confronting the experimental observables in a comprehensive and physics-based manner. In this chapter, we will summarize the currently emerging research efforts, which employ atomistic and coarse-grained molecular models and field theoretical models to understand equilibrium and nonequilibrium aspects of protein-RNA condensation.
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Affiliation(s)
- Rabia Laghmach
- Department of Chemistry, Iowa State University, Ames, IA, USA
| | - Isha Malhotra
- Department of Chemistry, Iowa State University, Ames, IA, USA
| | - Davit A Potoyan
- Department of Chemistry, Iowa State University, Ames, IA, USA.
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5
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Chen X, Chen EQ, Yang S. Multiphase Coacervation of Polyelectrolytes Driven by Asymmetry of Charged Sequence. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Xu Chen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, China
| | - Er-Qiang Chen
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, China
| | - Shuang Yang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry and Molecular Engineering, Peking University, Beijing100871, China
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6
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Yu B, Liang H, Rumyantsev AM, de Pablo JJ. Isotropic-to-Nematic Transition in Salt-Free Polyelectrolyte Coacervates from Coarse-Grained Simulations. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Boyuan Yu
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois60637, United States
| | - Heyi Liang
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois60637, United States
| | - Artem M. Rumyantsev
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois60637, United States
| | - Juan J. de Pablo
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois60637, United States
- Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois60439, United States
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7
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Xie O, Olsen BD. A Self-Consistent Field Theory Formalism for Sequence-Defined Polymers. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Oliver Xie
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Bradley D. Olsen
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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8
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Chen S, Zhang P, Wang ZG. Complexation between Oppositely Charged Polyelectrolytes in Dilute Solution: Effects of Charge Asymmetry. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00339] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shensheng Chen
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd., Pasadena, California 91125, United States
| | - Pengfei Zhang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-Dimension Materials, College of Materials and Engineering, Donghua University, Shanghai 201620, China
| | - Zhen-Gang Wang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd., Pasadena, California 91125, United States
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9
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Bale AA, Gautham SMB, Patra TK. Sequence‐defined Pareto frontier of a copolymer structure. JOURNAL OF POLYMER SCIENCE 2022. [DOI: 10.1002/pol.20220088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Ashwin A. Bale
- Department of Chemical Engineering Birla Institute of Technology and Science Pilani‐Hyderabad Hyderabad India
| | - Sachin M. B. Gautham
- Department of Chemical Engineering, Center for Atomistic Modeling and Materials Design and Center for Carbon Capture Utilization and Storage Indian Institute of Technology Madras Chennai India
| | - Tarak K. Patra
- Department of Chemical Engineering, Center for Atomistic Modeling and Materials Design and Center for Carbon Capture Utilization and Storage Indian Institute of Technology Madras Chennai India
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10
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Wessén J, Pal T, Chan HS. Field theory description of ion association in re-entrant phase separation of polyampholytes. J Chem Phys 2022; 156:194903. [DOI: 10.1063/5.0088326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Phase separation of several different overall neutral polyampholyte species (with zero net charge) is studied in solution with two oppositely charged ion species that can form ion-pairs through an association reaction. A field theory description of the system, that treats polyampholyte charge sequence dependent electrostatic interactions as well as excluded volume effects, is hereby given. Interestingly, analysis of the model using random phase approximation and field theoretic simulation consistently show evidence of a re-entrant polyampholyte phase separation at high ion concentrations when there is an overall decrease of volume upon ion-association. As an illustration of the ramifications of our theoretical framework, several polyampholyte concentration vs ion concentration phase diagrams under constant temperature conditions are presented to elucidate the dependence of phase separation behavior on polyampholyte sequence charge pattern as well as ion-pair dissociation constant, volumetric effects on ion association, solvent quality, and temperature.
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Affiliation(s)
- Jonas Wessén
- Department of Biochemsitry, University of Toronto, Canada
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11
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Gioldasis C, Gergidis LN, Vlahos C. Complexation of a Polyelectrolyte Brush with Oppositely Charged AB Diblock Copolymers: The Zipper Brushes. MACROMOL THEOR SIMUL 2022. [DOI: 10.1002/mats.202200011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Leonidas N. Gergidis
- Department of Materials Science & Engineering University of Ioannina Ioannina 45110 Greece
| | - Costas Vlahos
- Department of Chemistry University of Ioannina Ioannina 45110 Greece
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12
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Lebold KM, Best RB. Tuning Formation of Protein-DNA Coacervates by Sequence and Environment. J Phys Chem B 2022; 126:2407-2419. [PMID: 35317553 DOI: 10.1021/acs.jpcb.2c00424] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The high concentration of nucleic acids and positively charged proteins in the cell nucleus provides many possibilities for complex coacervation. We consider a prototypical mixture of nucleic acids together with the polycationic C-terminus of histone H1 (CH1). Using a minimal coarse-grained model that captures the shape, flexibility, and charge distributions of the molecules, we find that coacervates are readily formed at physiological ionic strengths, in agreement with experiment, with a progressive increase in local ordering at low ionic strength. Variation of the positions of charged residues in the protein tunes phase separation: for well-mixed or only moderately blocky distributions of charge, there is a modest increase of local ordering with increasing blockiness that is also associated with an increased propensity to phase separate. This ordering is also associated with a slowdown of rotational and translational diffusion in the dense phase. However, for more extreme blockiness (and consequently higher local charge density), we see a qualitative change in the condensed phase to become a segregated structure with a dramatically increased ordering of the DNA. Naturally occurring proteins with these sequence properties, such as protamines in sperm cells, are found to be associated with very dense packing of nucleic acids.
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Affiliation(s)
- Kathryn M Lebold
- Laboratory of Chemical Physics, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Robert B Best
- Laboratory of Chemical Physics, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, United States
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13
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Madinya JJ, Sing CE. Hybrid Field Theory and Particle Simulation Model of Polyelectrolyte–Surfactant Coacervation. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c00187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jason J. Madinya
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana−Champaign, 600 S. Matthews Ave., Urbana, Illinois 61820, United States
| | - Charles E. Sing
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana−Champaign, 600 S. Matthews Ave., Urbana, Illinois 61820, United States
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14
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Chang Q, Jiang J. Sequence Effects on the Salt-Enhancement Behavior of Polyelectrolytes Adsorption. Macromolecules 2022. [DOI: 10.1021/acs.macromol.1c02243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Qiuhui Chang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Jian Jiang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China
- University of Chinese Academy of Sciences, Beijing 100049, P.R. China
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15
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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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16
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Affiliation(s)
- Qiuhui Chang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jian Jiang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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17
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Jiang J, Chen EQ, Yang S. The effect of ion pairs on coacervate-driven self-assembly of block polyelectrolytes. J Chem Phys 2021; 154:144903. [PMID: 33858167 DOI: 10.1063/5.0044845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The incorporation of oppositely charged polyelectrolytes into a block copolymer system can lead to formation of microphase separated nanostructures driven by the electrostatic complex between two oppositely charged blocks. It is a theoretical challenge to build an appropriate model to handle such coacervate-driven self-assembly, which should capture the strong electrostatic correlations for highly charged polymers. In this paper, we develop the self-consistent field theory considering the ion paring effect to predict the phase behavior of block polyelectrolytes. In our model, two types of ion pairs, the binding between two oppositely charged monomers and the binding between charged monomers and counterions, are included. Their strength of formation is controlled by two parameters Kaa and Kac, respectively. We give a detailed analysis about how the binding strength Kac and Kaa and salt concentration affect the self-assembled nanostructure of diblock polyelectrolyte systems. The results show that the binding between two oppositely charged blocks provides driven force for microphase separation, while the binding between charged monomers and counterions competes with the polyion pairing and thus suppresses the microphase separation. The addition of salt has a shielding effect on the charges of polymers, which is a disadvantage to microphase separation. The phase diagrams as a function of polymer concentration and salt concentration at different situations are constructed, and the influence of Kaa, Kac, and charged block composition fa is analyzed in depth. The obtained phase diagrams are in good agreement with currently existing experimental and theoretical results.
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Affiliation(s)
- Jiadi Jiang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, People's Republic of China
| | - Er-Qiang Chen
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, People's Republic of China
| | - Shuang Yang
- Beijing National Laboratory for Molecular Sciences, Department of Polymer Science and Engineering and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, People's Republic of China
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18
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Grzetic DJ, Delaney KT, Fredrickson GH. Electrostatic Manipulation of Phase Behavior in Immiscible Charged Polymer Blends. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c00095] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Douglas J. Grzetic
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Kris T. Delaney
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
| | - Glenn H. Fredrickson
- Materials Research Laboratory, University of California, Santa Barbara, Santa Barbara, California 93106, United States
- Departments of Chemical Engineering and Materials, University of California, Santa Barbara, Santa Barbara, California 93106, United States
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19
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Abstract
A scaling model for the structure of coacervates is presented for mixtures of oppositely-charged polyelectrolytes of both symmetric and asymmetric charge-densities for different degrees of electrostatic strength and levels of added salt. At low electrostatic strengths, weak coacervates, with the energy of electrostatic interactions between charges less than the thermal energy, k B T, are liquid. At higher electrostatic strengths, strong coacervates are gels with crosslinks formed by ion pairs of opposite charges bound to each other with energy higher than k B T. Charge-symmetric coacervates are formed for mixtures of oppositely-charged polyelectrolytes with equal and opposite charge-densities. While charge-symmetric weak coacervates form a semidilute polymer solution with a correlation length equal to the electrostatic blob size, charge-symmetric strong coacervates form reversible gels with a correlation length on the order of the distance between bound ion pairs. Charge-asymmetric coacervates are formed from mixtures of oppositely-charged polyelectrolytes with different charge-densities. While charge-asymmetric weak coacervates form double solutions with two correlation lengths and qualitatively different chain conformations of polycations and polyanions, charge-asymmetric strong coacervates form bottlebrush and star-like gels. Unlike liquid coacervates, for which an increase in the concentration of added salt screens electrostatic interactions, causing structural rearrangement and eventually leads to their dissolution, the salt does not affect the structure of strong coacervates until ion pairs dissociate and the gel disperses.
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Affiliation(s)
- Scott P O Danielsen
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708, United States
| | - Sergey Panyukov
- P. N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow 117924, Russia
| | - Michael Rubinstein
- Department of Mechanical Engineering and Materials Science, Duke University, Durham, NC 27708, United States
- Departments of Biomedical Engineering, Physics, and Chemistry, Duke University, Durham, NC 27708, United States
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20
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Liu Y, Santa Chalarca CF, Carmean RN, Olson RA, Madinya J, Sumerlin BS, Sing CE, Emrick T, Perry SL. Effect of Polymer Chemistry on the Linear Viscoelasticity of Complex Coacervates. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00758] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yalin Liu
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Cristiam F. Santa Chalarca
- Department of Polymer Science & Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - R. Nicholas Carmean
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Rebecca A. Olson
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Jason Madinya
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Brent S. Sumerlin
- George & Josephine Butler Polymer Research Laboratory, Center for Macromolecular Science & Engineering, Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Charles E. Sing
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Todd Emrick
- Department of Polymer Science & Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Sarah L. Perry
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
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21
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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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Sing CE, Perry SL. Recent progress in the science of complex coacervation. SOFT MATTER 2020; 16:2885-2914. [PMID: 32134099 DOI: 10.1039/d0sm00001a] [Citation(s) in RCA: 317] [Impact Index Per Article: 79.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Complex coacervation is an associative, liquid-liquid phase separation that can occur in solutions of oppositely-charged macromolecular species, such as proteins, polymers, and colloids. This process results in a coacervate phase, which is a dense mix of the oppositely-charged components, and a supernatant phase, which is primarily devoid of these same species. First observed almost a century ago, coacervates have since found relevance in a wide range of applications; they are used in personal care and food products, cutting edge biotechnology, and as a motif for materials design and self-assembly. There has recently been a renaissance in our understanding of this important class of material phenomena, bringing the science of coacervation to the forefront of polymer and colloid science, biophysics, and industrial materials design. In this review, we describe the emergence of a number of these new research directions, specifically in the context of polymer-polymer complex coacervates, which are inspired by a number of key physical and chemical insights and driven by a diverse range of experimental, theoretical, and computational approaches.
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Affiliation(s)
- Charles E Sing
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews, Urbana, IL, USA.
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23
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Perry SL, Sing CE. 100th Anniversary of Macromolecular Science Viewpoint: Opportunities in the Physics of Sequence-Defined Polymers. ACS Macro Lett 2020; 9:216-225. [PMID: 35638672 DOI: 10.1021/acsmacrolett.0c00002] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Polymer science has been driven by ever-increasing molecular complexity, as polymer synthesis expands an already-vast palette of chemical and architectural parameter space. Copolymers represent a key example, where simple homopolymers have given rise to random, alternating, gradient, and block copolymers. Polymer physics has provided the insight needed to explore this monomer sequence parameter space. The future of polymer science, however, must contend with further increases in monomer precision, as this class of macromolecules moves ever closer to the sequence-monodisperse polymers that are the workhorses of biology. The advent of sequence-defined polymers gives rise to opportunities for material design, with increasing levels of chemical information being incorporated into long-chain molecules; however, this also raises questions that polymer physics must address. What properties uniquely emerge from sequence-definition? Is this circumstance-dependent? How do we define and think about sequence dispersity? How do we think about a hierarchy of sequence effects? Are more sophisticated characterization methods, as well as theoretical and computational tools, needed to understand this class of macromolecules? The answers to these questions touch on many difficult scientific challenges, setting the stage for a rich future for sequence-defined polymers in polymer physics.
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Affiliation(s)
- Sarah L. Perry
- Department of Chemical Engineering, University of Massachusetts−Amherst, 686 North Pleasant Street, Amherst, Massachusetts 01003, United States
| | - Charles E. Sing
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana−Champaign, 600 South Mathews Avenue Urbana, Illinois 61801, United States
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