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Confined polyelectrolytes: The complexity of a simple system.

Nunes, Sandra C C; Skepö, Marie LU and Pais, Alberto A C C (2015) In Journal of Computational Chemistry 36(21). p.1579-1586
Abstract
The interaction between polyelectrolytes and counterions in confined situations and the mutual relationship between chain conformation and ion condensation is an important issue in several areas. In the biological field, it assumes particular relevance in the understanding of the packaging of nucleic acids, which is crucial in the design of gene delivery systems. In this work, a simple coarse-grained model is used to assess the cooperativity between conformational change and ion condensation in spherically confined backbones, with capsides permeable to the counterions. It is seen that the variation on the degree of condensation depends on counterion valence. For monovalent counterions, the degree of condensation passes through a minimum... (More)
The interaction between polyelectrolytes and counterions in confined situations and the mutual relationship between chain conformation and ion condensation is an important issue in several areas. In the biological field, it assumes particular relevance in the understanding of the packaging of nucleic acids, which is crucial in the design of gene delivery systems. In this work, a simple coarse-grained model is used to assess the cooperativity between conformational change and ion condensation in spherically confined backbones, with capsides permeable to the counterions. It is seen that the variation on the degree of condensation depends on counterion valence. For monovalent counterions, the degree of condensation passes through a minimum before increasing as the confining space diminishes. In contrast, for trivalent ions, the overall tendency is to decrease the degree of condensation as the confinement space also decreases. Most of the particles reside close to the spherical wall, even for systems in which the density is higher closer to the cavity center. This effect is more pronounced, when monovalent counterions are present. Additionally, there are clear variations in the charge along the concentric layers that cannot be totally ascribed to polyelectrolyte behavior, as shown by decoupling the chain into monomers. If both chain and counterions are confined, the formation of a counterion rich region immediately before the wall is observed. Spool and doughnut-like structures are formed for stiff chains, within a nontrivial evolution with increasing confinement. © 2015 Wiley Periodicals, Inc. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Computational Chemistry
volume
36
issue
21
pages
1579 - 1586
publisher
John Wiley & Sons
external identifiers
  • pmid:26096545
  • wos:000357896900002
  • scopus:84936991162
ISSN
1096-987X
DOI
10.1002/jcc.23969
language
English
LU publication?
yes
id
b22146dd-e4f5-44fb-9500-26cb5648f5af (old id 7484246)
date added to LUP
2015-07-09 13:09:56
date last changed
2017-01-01 03:05:46
@article{b22146dd-e4f5-44fb-9500-26cb5648f5af,
  abstract     = {The interaction between polyelectrolytes and counterions in confined situations and the mutual relationship between chain conformation and ion condensation is an important issue in several areas. In the biological field, it assumes particular relevance in the understanding of the packaging of nucleic acids, which is crucial in the design of gene delivery systems. In this work, a simple coarse-grained model is used to assess the cooperativity between conformational change and ion condensation in spherically confined backbones, with capsides permeable to the counterions. It is seen that the variation on the degree of condensation depends on counterion valence. For monovalent counterions, the degree of condensation passes through a minimum before increasing as the confining space diminishes. In contrast, for trivalent ions, the overall tendency is to decrease the degree of condensation as the confinement space also decreases. Most of the particles reside close to the spherical wall, even for systems in which the density is higher closer to the cavity center. This effect is more pronounced, when monovalent counterions are present. Additionally, there are clear variations in the charge along the concentric layers that cannot be totally ascribed to polyelectrolyte behavior, as shown by decoupling the chain into monomers. If both chain and counterions are confined, the formation of a counterion rich region immediately before the wall is observed. Spool and doughnut-like structures are formed for stiff chains, within a nontrivial evolution with increasing confinement. © 2015 Wiley Periodicals, Inc.},
  author       = {Nunes, Sandra C C and Skepö, Marie and Pais, Alberto A C C},
  issn         = {1096-987X},
  language     = {eng},
  number       = {21},
  pages        = {1579--1586},
  publisher    = {John Wiley & Sons},
  series       = {Journal of Computational Chemistry},
  title        = {Confined polyelectrolytes: The complexity of a simple system.},
  url          = {http://dx.doi.org/10.1002/jcc.23969},
  volume       = {36},
  year         = {2015},
}