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Tagliabue A, Micheletti C, Mella M. Effect of Counterion Size on Knotted Polyelectrolyte Conformations. J Phys Chem B 2024; 128:4183-4194. [PMID: 38648610 DOI: 10.1021/acs.jpcb.3c07446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Using Langevin dynamics simulations and a coarse-grained primitive model of electrolytes, we show that the behavior of knotted circular strong polyelectrolytes (PEs) in diluted aqueous solution is largely affected by the diameter of the counterions (CIs), σCI. Indeed, we observe that both gyration radius and knot length vary nonmonotonically with σCI, with both small and bulky CIs favoring knot localization, while medium-sized ones promote delocalized knots. We also show that the conformational change from delocalized to tight knots occurs via the progressive coalescence of the knot's essential crossings. The emerging conformers correspond to the minima of the free energy landscape profiled as a function of the knot length or PE size. We demonstrate that different conformational states can coexist, the transition between them appearing first-order-like and controlled by the enthalpic and entropic trade-off of the amount of CIs condensed on the PE. Such balance can be further altered by varying CI concentrations, thus providing an additional and more convenient tuning parameter for the system properties. Our results lay the foundation for achieving broader and more precise external adjustability of knotted PE size and shape by choosing the nature of its CIs. Thus, they offer new intriguing possibilities for designing novel PE-based materials that are capable of responding to changes in ionic solution properties.
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Affiliation(s)
- Andrea Tagliabue
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 11, Como 22100, Italy
- SISSA (Scuola Internazionale Superiore di Studi Avanzati), via Bonomea 265, Trieste 34136, Italy
| | - Cristian Micheletti
- SISSA (Scuola Internazionale Superiore di Studi Avanzati), via Bonomea 265, Trieste 34136, Italy
| | - Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 11, Como 22100, Italy
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2
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On the role played by hydrogen bonding between water soluble polyacids and surfactants on their micellization as a function of pH. Colloids Surf A Physicochem Eng Asp 2023. [DOI: 10.1016/j.colsurfa.2023.130923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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3
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Tagliabue A, Micheletti C, Mella M. Tuning Knotted Copolyelectrolyte Conformations via Solution Properties. Macromolecules 2022. [DOI: 10.1021/acs.macromol.2c01933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Affiliation(s)
- Andrea Tagliabue
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell’Insubria, via Valleggio 11, 22100Como, Italy
- SISSA (Scuola Internazionale Superiore di Studi Avanzati), via Bonomea 265, 34136Trieste, Italy
| | - Cristian Micheletti
- SISSA (Scuola Internazionale Superiore di Studi Avanzati), via Bonomea 265, 34136Trieste, Italy
| | - Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell’Insubria, via Valleggio 11, 22100Como, Italy
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4
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Antignano I, D’Acunzo F, Arena D, Casciardi S, Del Giudice A, Gentile F, Pelosi M, Masci G, Gentili P. Influence of Nanoaggregation Routes on the Structure and Thermal Behavior of Multiple-Stimuli-Responsive Micelles from Block Copolymers of Oligo(ethylene glycol) Methacrylate and the Weak Acid [2-(Hydroxyimino)aldehyde]butyl Methacrylate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:14371-14386. [PMID: 36346681 PMCID: PMC9686140 DOI: 10.1021/acs.langmuir.2c02515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/20/2022] [Indexed: 06/16/2023]
Abstract
In this work, we compare nanoaggregation driven by pH-induced micellization (PIM) and by the standard solvent displacement (SD) method on a series of pH-, light-, and thermosensitive amphiphilic block copolymers. Specifically, we investigate poly(HIABMA)-b-poly(OEGMA) and poly(HIABMA)-b-poly(DEGMA-r-OEGMA), where HIABMA = [(hydroxyimino)aldehyde]butyl methacrylate, OEGMA = oligo(ethylene glycol)methyl ether methacrylate, and DEGMA = di(ethylene glycol)methyl ether methacrylate. The weakly acidic HIA group (pKa ≈ 8) imparts stability to micelles at neutral pH, unlike most of the pH-responsive copolymers investigated in the literature. With SD, only some of our copolymers yield polymeric micelles (34-59 nm), and their thermoresponsivity is either poor or altogether absent. In contrast, PIM affords thermoresponsive, smaller micelles (down to 24 nm), regardless of the polymer composition. In some cases, cloud points are remarkably well defined and exhibit limited hysteresis. By combining turbidimetric, dyamic light scattering, and small-angle X-ray scattering measurements, we show that SD yields loose micelles with POEGMA segments partly involved in the formation of the hydrophobic core, whereas PIM yields more compact core-shell micelles with a well-defined PHIABMA core. We conclude that pH-based nanoaggregation provides advantages over block-selective solvation to obtain compact micelles exhibiting well-defined responses to external stimuli.
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Affiliation(s)
- Irene Antignano
- Department
of Chemistry, Sapienza University of Rome, P.le A. Moro 5, 00185Roma, Italy
| | - Francesca D’Acunzo
- Institute
of Biological Systems (ISB), Italian National Research Council (CNR),
Sezione Meccanismi di Reazione, c/o Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185Roma, Italy
| | - Davide Arena
- Department
of Chemistry, Sapienza University of Rome, P.le A. Moro 5, 00185Roma, Italy
| | - Stefano Casciardi
- National
Institute for Insurance Against Accidents at Work (INAIL Research),
Department of Occupational and Environmental Medicine, Epidemiology and Hygiene, Via Fontana Candida 1, 00078Monte Porzio Catone (Rome), Italy
| | | | - Francesca Gentile
- Department
of Chemistry, Sapienza University of Rome, P.le A. Moro 5, 00185Roma, Italy
| | - Maria Pelosi
- Department
of Chemistry, Sapienza University of Rome, P.le A. Moro 5, 00185Roma, Italy
| | - Giancarlo Masci
- Department
of Chemistry, Sapienza University of Rome, P.le A. Moro 5, 00185Roma, Italy
| | - Patrizia Gentili
- Department
of Chemistry, Sapienza University of Rome, P.le A. Moro 5, 00185Roma, Italy
- Institute
of Biological Systems (ISB), Italian National Research Council (CNR),
Sezione Meccanismi di Reazione, c/o Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185Roma, Italy
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5
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Interaction between surfaces decorated with like-charged pendants: Unravelling the interplay between energy and entropy leading to attraction. J Colloid Interface Sci 2022; 619:51-64. [DOI: 10.1016/j.jcis.2022.03.065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/12/2022] [Accepted: 03/14/2022] [Indexed: 11/18/2022]
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6
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Mella M, Tagliabue A, Viscusi G, Gorrasi G, Izzo L. How chemical structure and composition impact on the release of salt-like drugs from hydrophobic matrices: Variation of mechanism upon adding hydrophilic features to PMMA. Colloids Surf A Physicochem Eng Asp 2022. [DOI: 10.1016/j.colsurfa.2022.128878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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7
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Zhou S. Effective electrostatic forces between two neutral surfaces with surface charge separation: valence asymmetry and dielectric constant heterogeneity. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2094296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- S. Zhou
- School of Physics and Electronics, Central South University, Changsha, People’s Republic of China
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Mella M, Tagliabue A. Impact of Chemically Specific Interactions between Anions and Weak Polyacids on Chain Ionization, Conformations, and Solution Energetics. Macromolecules 2022. [DOI: 10.1021/acs.macromol.1c02625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell’Insubria, via Valleggio 11, 22100 Como (I), Italy
| | - Andrea Tagliabue
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell’Insubria, via Valleggio 11, 22100 Como (I), Italy
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Mella M, Tagliabue A, Mollica L, Vaghi S, Izzo L. Inducing pH control over the critical micelle concentration of zwitterionic surfactants via polyacids adsorption: Effect of chain length and structure. J Colloid Interface Sci 2022; 606:1636-1651. [PMID: 34500165 DOI: 10.1016/j.jcis.2021.07.076] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
HYPOTHESIS The critical concentration above which micelles form from zwitterionic surfactant solutions and their thermodynamic stability is affected by the interaction with weak Brønsted polyacid chains (An) via the formation of charged hydrogen bonds between the latter and anionic moieties. EXPERIMENTS The interaction between zwitterionic micelles and polyacids capable of forming hydrogen bonds, and its dependence on the environmental pH and polymer structure, has been studied with constant-pH simulations and a restricted primitive model for all electrolytes. FINDINGS At low pH, the formation of polyacid/micelle complexes is witnessed independently of the polymer size or structure, so that the concentration above which micelles form is substantially decreased compared to polyacid-free cases. Upon rising pH, polymer desorption takes place within a narrow range of pH values, its location markedly depending on the size and structure of polyacids, and on the relative disposition between headgroup charged moieties. Thus, the desorption onset for long linear polyacids (A60) interacting with sulphobetainic headgroups is roughly two pH units higher than for six decameric chains (6A10) adsorbed onto micelles bearing phosphorylcholinic headgroups. This effect, together with the preferential desorption of chain ends at intermediate pH, may be exploited for drug delivery purposes or building advanced metamaterials.
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Affiliation(s)
- Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 9, 22100 Como, Italy.
| | - Andrea Tagliabue
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 9, 22100 Como, Italy
| | - Luca Mollica
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Vanvitelli 32, 20133 Milano, Italy
| | - Stefano Vaghi
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 9, 22100 Como, Italy
| | - Lorella Izzo
- Dipartimento di Biotecnologie e Scienze della Vita, Universitá degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy
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Tagliabue A, Micheletti C, Mella M. Tunable Knot Segregation in Copolyelectrolyte Rings Carrying a Neutral Segment. ACS Macro Lett 2021; 10:1365-1370. [PMID: 35549022 DOI: 10.1021/acsmacrolett.1c00453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We use Langevin dynamics simulations to study the knotting properties of copolyelectrolyte rings carrying neutral segments. We show that by solely tuning the relative length of the neutral and charged blocks, one can achieve different combinations of knot contour position and size. Strikingly, the latter is shown to vary nonmonotonically with the length of the neutral segment; at the same time, the knot switches from being pinned at the block's edge to becoming trapped inside it. Model calculations relate both effects to the competition between two adversarial mechanisms: the energy gain of localizing one or more of the knot's essential crossings on the neutral segment and the entropic cost of such localization. Tuning the length of the neutral segment sets the balance between the two mechanisms and hence the number of localized essential crossings, which in turn modulates the knot's size. This general principle ought to be useful in more complex systems, such as multiblock copolyelectrolytes, to achieve a more granular control of topological constraints.
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Affiliation(s)
- Andrea Tagliabue
- Dipartimento di Scienza ed Alta Tecnologia, Universitá degli Studi dell’Insubria, via Valleggio 11, 22100, Como, Italy
| | - Cristian Micheletti
- SISSA (Scuola Internazionale Superiore di Studi Avanzati), via Bonomea 265, 34136, Trieste, Italy
| | - Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Universitá degli Studi dell’Insubria, via Valleggio 11, 22100, Como, Italy
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11
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Mella M, Tagliabue A, Vaghi S, Izzo L. Evidences for charged hydrogen bonds on surfaces bearing weakly basic pendants: The case of PMMA–ran–PDMAEMA polymeric films. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126525] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Tagliabue A, Landsgesell J, Mella M, Holm C. Can oppositely charged polyelectrolyte stars form a gel? A simulational study. SOFT MATTER 2021; 17:1574-1588. [PMID: 33351002 DOI: 10.1039/d0sm01617a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We present a Langevin molecular dynamics study of an equimolar mixture of monodispersed oppositely charged di-block four-armed polyelectrolyte stars. We used an implicit solvent coarse-grained representation of the polyelectrolyte stars, and varied the length of the terminal charged blocks that reside on each arm. By varying the polymer concentration, we computed PV diagrams and determined the free-swelling equilibrium concentration with respect to a pure water reservoir as a function of the charged block length. We investigated various structural properties of the resulting equilibrium structures, like the number of ionic bonds, dangling arms, isolated stars, and cluster sizes. The ionic bonds featured a broad distribution of the number of arms involved and also displayed a distribution of net charges peaked around the neutral ionic bond. Our main result is that for charged block length equal to 4 and 5 ionized beads the resulting macro-aggregate spans the box and forms a network phase. Furthermore, we investigated the restructuring dynamics of ionic bonds; the results suggested both short bond lifetimes and a high frequency of ballistic association/dissociation events. Bonds result strong enough to yield a stable gel phase, but they are still weak enough to allow network restructuring under thermal fluctuations.
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Affiliation(s)
- Andrea Tagliabue
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 9, 22100, Como, Italy
| | - Jonas Landsgesell
- Institute for Computational Physics, University of Stuttgart, Allmandring 3, Stuttgart, 70569, Germany.
| | - Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 9, 22100, Como, Italy
| | - Christian Holm
- Institute for Computational Physics, University of Stuttgart, Allmandring 3, Stuttgart, 70569, Germany.
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13
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Mella M, Tagliabue A, Izzo L. On the distribution of hydrophilic polyelectrolytes and their counterions around zwitterionic micelles: the possible impact on the charge density in solution. SOFT MATTER 2021; 17:1267-1283. [PMID: 33300543 DOI: 10.1039/d0sm01541e] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Despite their charge neutrality, micelles composed of surfactants with zwitterionic headgroups selectively accumulate anions at their hydrophobic core/solution interphase due to electrostatic interactions if headgroup positive moieties are the innermost. This tendency may be markedly enhanced if polyions substitute simple ions. To investigate this possibility, solutions composed of zwitterionic micelles and hydrophilic polyanions have been investigated with Monte Carlo simulations representing the studied systems via primitive electrolyte models. Structural and energetic properties are obtained to highlight the impact of connecting simple ions into polyions on the interactions between electrolytes and micelles. Despite the latter, polyanions conserve their conformational properties. A marked increase in the concentration of charged species inside the micellar corona is, instead, found when polyions are present independently of their charge sign or the headgroup structure. Thus, polyelectrolytes act as "shuttle" for all charged species, with the potential of increasing reactions rates involving the latter due to mass effects. Besides, results for the polyions/micelles mixing free energy and Helmholtz energy profiles indicate that the critical micelle concentration is impacted minimally by hydrophilic polyelectrolytes, an outcome agreeing with experiments. This finding is entirely due to weak enthalpic effects while mixing hydrophilic polyions and micelles. A strong reduction in the screening of the micelle negative charge, acquired following the adsorption of anions in the corona and due to counterions layering just outside it (the so called "chameleon effect"), is forecasted when polyanions substitute monovalent anions.
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Affiliation(s)
- Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 11, 22100, Como, Italy.
| | - Andrea Tagliabue
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 11, 22100, Como, Italy.
| | - Lorella Izzo
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100, Varese, Italy
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14
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Tagliabue A, Izzo L, Mella M. Interface Counterion Localization Induces a Switch between Tight and Loose Configurations of Knotted Weak Polyacid Rings despite Intermonomer Coulomb Repulsions. J Phys Chem B 2020; 124:2930-2937. [PMID: 32154720 DOI: 10.1021/acs.jpcb.0c00620] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Stochastic simulations have been used to investigate the conformational behavior of knotted weak polyacid rings as a function of pH. Different from the commonly expected ionization-repulsion-expansion scheme upon increasing pH, theoretical results suggest a nonmonotonic behavior of the gyration radius Rg2. Polyelectrolyte recontraction at high ionization is induced by the weakening of Coulomb repulsion due to counterions (CIs) localizing at the interphase between the polymer and solvent, and the more marked it appears, the more complex is the knot topology. Compared with strong polyelectrolytic species of identical ionization, weak polyacids present tighter knots due to their ability to localize neutral monomers inside the tangled part. Increasing the solvent Bjerrum length enhances CIs localization, lowering the pH at which polyacids start decreasing their average size. A similar effect is also obtained by increasing the amount of "localizable" cations by adding salts.
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Affiliation(s)
- Andrea Tagliabue
- Dipartimento di Scienza ed Alta Tecnologia, Universitá degli Studi dell'Insubria, via Valleggio 9, 22100 Como, Italy
| | - Lorella Izzo
- Dipartimento di Biotecnologie e Scienze della Vita, Universitá degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy
| | - Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Universitá degli Studi dell'Insubria, via Valleggio 9, 22100 Como, Italy
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Miele Y, Mingotaud AF, Caruso E, Malacarne MC, Izzo L, Lonetti B, Rossi F. Hybrid giant lipid vesicles incorporating a PMMA-based copolymer. Biochim Biophys Acta Gen Subj 2020; 1865:129611. [PMID: 32272202 DOI: 10.1016/j.bbagen.2020.129611] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/16/2020] [Accepted: 04/02/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND In recent years, there has been a growing interest in the formation of copolymer-lipid hybrid self-assemblies, which allow combining and improving the main features of pure lipid-based and copolymer-based systems known for their potential applications in the biomedical field. As the most common method used to obtain giant vesicles is electroformation, most systems so far used low Tg polymers for their flexibility at room temperature. METHODS Copolymers used in the hybrid vesicles have been synthesized by a modified version of the ATRP, namely the Activators ReGenerated by Electron Transfer ATRP and characterized by NMR and DSC. Giant hybrid vesicles have been obtained using electroformation and droplet transfer method. Confocal fluorescence microscopy was used to image the vesicles. RESULTS Electroformation enabled to obtain hybrid vesicles in a narrow range of compositions (15 mol% was the maximum copolymer content). This range could be extended by the use of a droplet transfer method, which enabled obtaining hybrid vesicles incorporating a methacrylate-based polymer in a wide range of compositions. Proof of the hybrid composition was obtained by fluorescence microscopy using labeled lipids and copolymers. CONCLUSIONS This work describes for the first time, to the best of our knowledge, the formation of giant hybrid polymer/lipid vesicles formed with such a content of a polymethylmethacrylate copolymer, the glass temperature of which is above room temperature. GENERAL SIGNIFICANCE This work shows that polymer structures, more complex than the ones mostly employed, can be possibly included in giant hybrid vesicles by using the droplet transfer method. This will give easier access to functionalized and stimuli-responsive giant vesicles and to systems exhibiting a tunable permeability, these systems being relevant for biological and technological applications.
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Affiliation(s)
- Ylenia Miele
- Department of Chemistry and Biology, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano, Italy
| | - Anne-Françoise Mingotaud
- Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 Rte de Narbonne, F-31062 Toulouse cedex 9, France
| | - Enrico Caruso
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J. H. Dunant, 3, 21100 Varese, Italy
| | - Miryam C Malacarne
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J. H. Dunant, 3, 21100 Varese, Italy
| | - Lorella Izzo
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J. H. Dunant, 3, 21100 Varese, Italy.
| | - Barbara Lonetti
- Laboratoire des IMRCP, Université de Toulouse, CNRS UMR 5623, Université Toulouse III - Paul Sabatier, 118 Rte de Narbonne, F-31062 Toulouse cedex 9, France.
| | - Federico Rossi
- Department of Earth, Environmental and Physical Sciences - DEEP Sciences - Pian dei Mantellini 44, 53100 Siena, Italy
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Mella M, Tagliabue A, Mollica L, Izzo L. Monte Carlo study of the effects of macroion charge distribution on the ionization and adsorption of weak polyelectrolytes and concurrent counterion release. J Colloid Interface Sci 2020; 560:667-680. [PMID: 31704002 DOI: 10.1016/j.jcis.2019.10.051] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 10/12/2019] [Accepted: 10/14/2019] [Indexed: 01/16/2023]
Abstract
HYPOTHESIS Adsorption of weak polyelectrolytes onto charged nanoparticles, and concurrent effects such as spatial partitioning of ions may be influenced by details of the polyelectrolyte structure (linear or star-like) and size, by the mobility of the nanoparticle surface charge, or the valence of the nanoparticle counterions. EXPERIMENTS Ionization and complexation of weak polyelectrolytes on spherical macroions with monovalent and divalent countrions has been studied with constant-pH Monte Carlo titrations and primitive electrolyte models for linear and star-like polymers capable, also, of forming charged hydrogen bonds. Nanoparticles surface charge has been represented either as a single colloid-centered total charge (CCTC) or as surface-tethered mobile monovalent spherical charges (SMMSC). FINDINGS Differences in the average number of adsorbed polyelectrolyte arms and their average charge, and in the relative amount of macroion counterions (m-CI's) released upon polymer adsorption are found between CCTC and SMMSC nanoparticles. The amount of the counterions released also depends on the polymer structure. As CCTC adsorbs a lower number of star-like species arms, the degree of condensation of polymer counterions (p-CI's) onto the polyelectrolyte is also substantially higher for the CCTC colloid, with a concurrent decrease of the osmotic coefficient values.
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Affiliation(s)
- Massimo Mella
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 11, 22100 Como, Italy.
| | - Andrea Tagliabue
- Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, via Valleggio 11, 22100 Como, Italy
| | - Luca Mollica
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Vanvitelli 32, 20133 Milano, Italy; Istituto Nazionale Genetica Molecolare "Romeo ed Enrica Invernizzi", Via F. Sforza 35, 20122 Milano, Italy
| | - Lorella Izzo
- Dipartimento di Biotecnologie e Scienze della Vita, Università degli Studi dell'Insubria, via J. H. Dunant 3, 21100 Varese, Italy.
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