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Hriberšek P, Kogej K. Tacticity and Counterion Modulated Temperature Response of Weak Polyelectrolytes: The Case of Poly(methacrylic acid) Stereoisomers in Aqueous Solutions. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01467] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Patricija Hriberšek
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana SI-1000, Slovenia
| | - Ksenija Kogej
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana SI-1000, Slovenia
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Viscosity of Plasma as a Key Factor in Assessment of Extracellular Vesicles by Light Scattering. Cells 2019; 8:cells8091046. [PMID: 31500151 PMCID: PMC6769602 DOI: 10.3390/cells8091046] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/19/2019] [Accepted: 09/04/2019] [Indexed: 12/31/2022] Open
Abstract
Extracellular vesicles (EVs) isolated from biological samples are a promising material for use in medicine and technology. However, the assessment methods that would yield repeatable concentrations, sizes and compositions of the harvested material are missing. A plausible model for the description of EV isolates has not been developed. Furthermore, the identity and genesis of EVs are still obscure and the relevant parameters have not yet been identified. The purpose of this work is to better understand the mechanisms taking place during harvesting of EVs, in particular the role of viscosity of EV suspension. The EVs were harvested from blood plasma by repeated centrifugation and washing of samples. Their size and shape were assessed by using a combination of static and dynamic light scattering. The average shape parameter of the assessed particles was found to be ρ ~ 1 (0.94–1.1 in exosome standards and 0.7–1.2 in blood plasma and EV isolates), pertaining to spherical shells (spherical vesicles). This study has estimated the value of the viscosity coefficient of the medium in blood plasma to be 1.2 mPa/s. It can be concluded that light scattering could be a plausible method for the assessment of EVs upon considering that EVs are a dynamic material with a transient identity.
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Effect of Multivalent Cations on Intermolecular Association of Isotactic and Atactic Poly(Methacrylic Acid) Chains in Aqueous Solutions. Polymers (Basel) 2019; 11:polym11040605. [PMID: 30960589 PMCID: PMC6523823 DOI: 10.3390/polym11040605] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 03/22/2019] [Accepted: 03/26/2019] [Indexed: 11/18/2022] Open
Abstract
The formation of nanoparticles of two poly(methacrylic acid) (PMA) isomers, atactic (aPMA) and isotactic (iPMA), was investigated in aqueous solutions in the presence of mono- (Na+) and multivalent cations (Mg2+ and La3+). Using dynamic (DLS) and static light scattering (SLS), we show that PMA nanoparticles have characteristics of microgel-like particles with a denser core and a swollen corona. iPMA aggregates are stable at a much higher degree of neutralization (αN) than the aPMA ones, indicating a much stronger association between iPMA chains. This is explained by proposing segregation of ionized and unionized carboxyl groups within the iPMA aggregates and subsequent cooperative hydrogen-bonding between COOH groups. The calculated shape parameter (ρ) suggests different behavior of both isomers in the presence of Mg2+ ions on one hand and Na+ and La3+ on the other. The microgel-like particles formed in the presence of Mg2+ ions have a more even mass distribution (possibly a no core-shell structure) in comparison with those in the presence of Na+ and La3+ ions. Differences between the aggregate structures in the presence of different ions are reflected also in calorimetric experiments and supported by pH and fluorimetric measurements. Reasons for different behavior in the presence of Mg2+ ions lie in specific properties of this cation, in particular in its strong hydration and preference towards monodentate binding to carboxylate groups.
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Aggregation and microstructure of cereal β-glucan and its association with other biomolecules. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2018.10.042] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Zielke C, Stradner A, Nilsson L. Characterization of cereal β-glucan extracts: Conformation and structural aspects. Food Hydrocoll 2018. [DOI: 10.1016/j.foodhyd.2017.12.036] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Glagoleva AA, Vasilevskaya VV. Macromolecules with amphiphilic monomer units at interface of two immiscible liquids. J Chem Phys 2017; 147:184902. [DOI: 10.1063/1.5001880] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- A. A. Glagoleva
- A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova ul. 28, Moscow 119991, Russia
| | - V. V. Vasilevskaya
- A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova ul. 28, Moscow 119991, Russia
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Sitar S, Aseyev V, Kogej K. Microgel-like aggregates of isotactic and atactic poly(methacrylic acid) chains in aqueous alkali chloride solutions as evidenced by light scattering. SOFT MATTER 2014; 10:7712-7722. [PMID: 25137480 DOI: 10.1039/c4sm01448k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A comparative light-scattering study of isotactic and atactic poly(methacrylic acid), iPMA and aPMA, respectively, in aqueous solutions with added alkali chlorides, XCl (X = Li, Na, Cs), at 25 °C and XCl concentration of 0.1 mol L(-1), demonstrates that both PMA isomers are strongly associated at low degrees of neutralization, αN (= 0 for aPMA and 0.25 for iPMA), in the presence of all XCls. The shape parameter ρ and the scattering functions suggest that aggregates have the characteristics of microgel particles, with a dense core surrounded by a less dense shell. The extent of aggregation depends on the stereoregular structure of the polymer and on the type of the added cation. Li(+) and Na(+) ions support aggregation better than Cs(+) ions. Besides, iPMA chains are more strongly aggregated than aPMA chains and form particles with a denser core. A model of the aggregation process is suggested for iPMA. At high αN, a slow diffusive process (so-called extraordinary or anomalous mode in diffusion of polyelectrolytes), arising from electrostatic interactions between charged chains, is observed for both PMAs. Results suggest that under the same experimental conditions iPMA is effectively more charged than aPMA. The role of ions in the slow-mode phenomenon is less pronounced than in aggregation.
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Affiliation(s)
- Simona Sitar
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, P.O. Box 537, SI-1001, Ljubljana, Slovenia.
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Sitar S, Aseyev V, Kogej K. Differences in association behavior of isotactic and atactic poly(methacrylic acid). POLYMER 2014. [DOI: 10.1016/j.polymer.2014.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Renamayor CS, Pastoriza A, Usma CL, Pierola IF. Ionic liquid–water mixtures as solvents for poly(N-vinylimidazole). Colloid Polym Sci 2013. [DOI: 10.1007/s00396-013-2963-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Unusual behavior in light scattering experiments of poly(N-vinylimidazole) prepared by precipitation polymerization. Colloid Polym Sci 2009. [DOI: 10.1007/s00396-009-2104-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Huang X, Misra GP, Vaish A, Flanagan JM, Sutermaster B, Lowe TL. Novel Nanogels with Both Thermoresponsive and Hydrolytically Degradable Properties. Macromolecules 2008. [DOI: 10.1021/ma800081g] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiao Huang
- Departments of Surgery, Bioengineering, and Materials Science and Engineering, Pennsylvania State University, 500 University Drive, Hershey, Pennsylvania 17033
| | - Gauri P. Misra
- Departments of Surgery, Bioengineering, and Materials Science and Engineering, Pennsylvania State University, 500 University Drive, Hershey, Pennsylvania 17033
| | - Amit Vaish
- Departments of Surgery, Bioengineering, and Materials Science and Engineering, Pennsylvania State University, 500 University Drive, Hershey, Pennsylvania 17033
| | - John M. Flanagan
- Departments of Surgery, Bioengineering, and Materials Science and Engineering, Pennsylvania State University, 500 University Drive, Hershey, Pennsylvania 17033
| | - Bryan Sutermaster
- Departments of Surgery, Bioengineering, and Materials Science and Engineering, Pennsylvania State University, 500 University Drive, Hershey, Pennsylvania 17033
| | - Tao Lu Lowe
- Departments of Surgery, Bioengineering, and Materials Science and Engineering, Pennsylvania State University, 500 University Drive, Hershey, Pennsylvania 17033
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Shen L, Wang H, Guerin G, Wu C, Manners I, Winnik MA. A Micellar Sphere-to-Cylinder Transition of Poly(ferrocenyldimethylsilane-b-2-vinylpyridine) in a Selective Solvent Driven by Crystallization. Macromolecules 2008. [DOI: 10.1021/ma702852j] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lei Shen
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6, The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, Anhui, China, Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, and School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Hai Wang
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6, The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, Anhui, China, Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, and School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Gerald Guerin
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6, The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, Anhui, China, Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, and School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Chi Wu
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6, The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, Anhui, China, Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, and School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Ian Manners
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6, The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, Anhui, China, Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, and School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Mitchell A. Winnik
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6, The Hefei National Laboratory for Physical Sciences at Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei 230026, Anhui, China, Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong, and School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
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Tarassova E, Aseyev V, Filippov A, Tenhu H. Structure of poly(vinyl pyrrolidone) – C70 complexes in aqueous solutions. POLYMER 2007. [DOI: 10.1016/j.polymer.2007.05.069] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Trappe V, Leukel J, Burchard W. Branched Architectures from Anhydride Cured Glycidylethers. J MACROMOL SCI B 2007. [DOI: 10.1080/00222340500332392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Veronique Trappe
- a Institute of Macromolecular Chemistry , “Albert‐Ludwig” University of Freiburg , Freiburg, Germany
| | - Jörg Leukel
- a Institute of Macromolecular Chemistry , “Albert‐Ludwig” University of Freiburg , Freiburg, Germany
| | - Walther Burchard
- a Institute of Macromolecular Chemistry , “Albert‐Ludwig” University of Freiburg , Freiburg, Germany
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Boyko V, Richter S, Burchard W, Arndt KF. Chain dynamics in microgels: poly(N-vinylcaprolactam-co-N-vinylpyrrolidone) microgels as examples. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:776-84. [PMID: 17209633 DOI: 10.1021/la062181+] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Microgels are highly swollen colloids built up of flexible cross-linked chains. We studied the static and dynamic light scattering (LS) behavior of thermosensitive microgels based on N-vinylcaprolactam and N-vinylpyrrolidone prepared by precipitation copolymerization in H2O (CP-1) and D2O (CP-2). Striking differences in behavior were observed in the two solvents. In both cases the angular dependence of static LS could reasonably well be described by a soft sphere model (J. Polym. Sci., Polym. Phys. Ed. 1982, 20, 157) with small deviations at large qRg. At temperatures larger than the collapse temperatures, the CP-1 sample in water started to aggregate whereas the CP-2 sample in D2O showed no association and developed the expected change toward hard sphere behavior. Dynamic LS permitted the determination of internal or segmental mobility. A remarkable shift toward large qRg was found for CP-1 compared to the behavior of linear chains. The dynamic behavior is clearly displayed in a plot of Gamma*(q) = (Gamma1(q)/q3)(eta0/kT), with Gamma1(q) the first cumulant of the field time correlation function and the common meaning of the other parameters. A long range of hard sphere behavior indicated the suppression of internal modes, but at large qRg the swollen microgel CP-1 in water displayed internal motions with a spectrum similar to that of Zimm relaxations. No internal mobility could be detected with the CP-2 sample in D2O. The behavior is in agreement with observations in the literature. The differences in the two similar solvents were attributed to the poorer solvent quality of D2O.
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Affiliation(s)
- Volodymyr Boyko
- Physical Chemistry of Polymers, Dresden University of Technology, Dresden, Germany
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Vasilevskaya VV, Markov VA, Khalatur PG, Khokhlov AR. Semiflexible amphiphilic polymers: Cylindrical-shaped, collagenlike, and toroidal structures. J Chem Phys 2006; 124:144914. [PMID: 16626252 DOI: 10.1063/1.2191049] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A coarse-grained model is used to study the conformational properties of semiflexible polymers with amphiphilic monomer units containing both hydrophilic and hydrophobic interaction sites. The hydrophobically driven conformational transitions are studied using molecular dynamics simulations for the chains of varying stiffness, as characterized by intrinsic Kuhn segment lengths that vary over a decade. It is shown that the energy of hydrophobic attraction required for the realization of the coil-to-globule transition increases with increasing chain stiffness. For rather stiff backbone, the coil-to-globule transition corresponds to a first order phase transition. We find that depending on the chain stiffness, a variety of thermodynamically stable anisometric chain morphologies are possible in a solvent selectively poor for hydrophobic sites of amphiphilic monomer units. For flexible chains, the amphiphilic polymer forms a cylindrical globule having blob structure with nearly spherical blobs. With increasing stiffness, the number of blobs composing the globule decreases and the shape of blobs transforms into elongated cylinder. Further increase in stiffness leads to compaction of macromolecules into a collagenlike structure when the chain folds itself several times and different strands wind round each other. In this state, the collagenlike structures coexist with toroidal globules, both conformations having approximately equal energies.
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Burchard W. Angular Dependence of Scattered Light from Hyperbranched Structures in a Good Solvent. A Fractal Approach. Macromolecules 2004. [DOI: 10.1021/ma049950l] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Walther Burchard
- Institute of Macromolecular Chemistry, Albert-Ludwig University of Freiburg, 79104 Freiburg
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