Microscopics of Complexation between Long DNA Molecules and Positively Charged Colloids

Keren, Kinneret; Soen, Yoav; Yoseph, G. Ben; Gilad, Rachel; Braun, Erez; Sivan, Uri; Talmon, Yeshayahu

doi:10.1103/physrevlett.89.088103

Cited by 91 publications

(104 citation statements)

References 18 publications

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“…Eventually, when the particle surface is completely saturated by the adsorbed polyelectrolyte and the overcharging has reached its plateau value, the size of the particles in the suspension equals again the size of the primary particles ('reentrant condensation') plus a thin layer of adsorbed polymer [3,8,6]. This reentrant condensation has been observed in a variety of colloidal systems, ranging from polyelectrolyte-micelle complexes [2], latex particles [29], dendrimers [30], phospholipid vesicles (liposomes) [31,4,8], to 'hybrid niosomal' vesicles [12]. Although the adsorption patterns are further complicated by the presence of short-range interactions specific to the different systems, the similarities in the observed behavior for such different systems strongly indicate that the overall phenomenology is mainly governed by electrostatic interactions, arising from double layer overlap (repulsion) and surface charge non-uniformity (attraction).…”

Section: Introductionmentioning

confidence: 99%

Effect of Temperature on the Reentrant Condensation in Polyelectrolyte−Liposome Complexation

et al. 2008

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Interactions of oppositely charged macroions in aqueous solution give rise to intriguing aggregation phenomena, resulting in finite-size, longlived clusters, characterized by a quite narrow size distribution. Particularly, the adsorption of highly charged linear polyelectrolytes on oppositely charged colloidal particles is strongly correlated and some short-range order arises from competing electrostatic interactions between like-charged polymer chains (repulsion) and between polymer chains and particle surface (attraction). The charge inversion observed for the polyelectrolytedecorated primary particles has been recently explained in terms of correlated adsorption. In these systems, long-lived clusters of polyelectrolytedecorated particles form in an interval of concentrations around the inversion point. However, the mechanisms that drive the aggregation and stabilize, at the different polymer/particle ratios, a well defined size of the aggregates are not completely understood. Nor is clear the role that the correlated adsorption plays in the aggregation, although the importance of 'patchy interactions' has been stressed as the possible source of attractive interactions between colloidal particles. Different models have been introduced to explain the formation of the observed finite-size cluster phase. However a central question still remains unanswered, i.e., whether the clusters are true equilibrium or metastable aggregates. To elucidate this point, in this work, we have investigated the effect of the temperature on the formation of the clusters. We employed liposomes built up by DOTAP lipid interacting with a simple anionic polyion, sodium polyacrylate, over an extended concentration range below and over the isoelectric condition. Our results show that the aggregation process can be described by a thermally-activated mechanism.

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Section: Introductionmentioning

confidence: 99%

Effect of Temperature on the Reentrant Condensation in Polyelectrolyte−Liposome Complexation

et al. 2008

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“…An artificial chromatin system in the presence of monovalent salt is studied in experiments 20 , where the phase diagram of reentrant condensation is found and the domain of partial aggregation is not observed. This is qualitatively consistent with our theory that the relative size of the partial aggregation domain is small due to screening effect of monovalent salt.…”

Section: Rmentioning

confidence: 99%

Phase diagram of aggregation of oppositely charged colloids in salty water

Zhang

Shklovskiǐ

2004

Phys. Rev. E

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Aggregation of two oppositely charged colloids in salty water is studied. We focus on the role of Coulomb interaction in strongly asymmetric systems in which the charge and size of one colloid is much larger than the other one. In the solution, each large colloid (macroion) attracts certain number of oppositely charged small colloids (Z-ion) to form a complex. If the concentration ratio of the two colloids is such that complexes are not strongly charged, they condense in a macroscopic aggregate. As a result, the phase diagram in a plane of concentrations of two colloids consists of an aggregation domain sandwiched between two domains of stable solutions of complexes. The aggregation domain has a central part of total aggregation and two wings corresponding to partial aggregation. A quantitative theory of the phase diagram in the presence of monovalent salt is developed. It is shown that as the Debye-Hückel screening radius rs decreases, the aggregation domain grows, but the relative size of the partial aggregation domains becomes much smaller. As an important application of the theory, we consider solutions of long double-helix DNA with strongly charged positive spheres (artificial chromatin). We also consider implications of our theory for in vitro experiments with the natural chromatin. Finally, the effect of different shapes of macroions on the phase diagram is discussed.

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“…This intriguing phenomenology has been observed in a variety of polyelectrolyte-colloid systems dispersed in aqueous solutions such as polyelectrolyte-micelle complexes, [20] latex particles [21,22], dendrimers [23], ferric oxide particles [24], phospholipid vesicles (liposomes) [25][26][27], 'hybrid niosome' vesicles [28].…”

Section: Introductionmentioning

confidence: 99%

Interaction between like-charged polyelectrolyte-colloid complexes in electrolyte solutions: A Monte Carlo simulation study in the Debye–Hückel approximation

Truzzolillo

Bordi

Sciortino

et al. 2010

The Journal of Chemical Physics

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We study the effective interaction between differently charged polyelectrolyte-colloid complexes in electrolyte solutions via Monte Carlo simulations. These complexes are formed when short and flexible polyelectrolyte chains adsorb onto oppositely charged colloidal spheres, dispersed in an electrolyte solution. In our simulations the bending energy between adjacent monomers is small compared to the electrostatic energy, and the chains, once adsorbed, do not exchange with the solution, although they rearrange on the particles surface to accomodate further adsorbing chains or due to the electrostatic interaction with neighbor complexes. Rather unexpectedly, when two interacting particles approach each others, the rearrangement of the surface charge distribution invariably produces anti-parallel dipolar doublets, that invert their orientation at the isoelectric point. These findings clearly rule out a contribution of dipole-dipole interactions to the observed attractive interaction between the complexes, pointing out that such suspensions can not be considered dipolar fluids. On varying the ionic strength of the electrolyte, we find that a screening length κ −1 , short compared with the size of the colloidal particles, is required in order to observe the attraction between like charged complexes due to the non-uniform distribution of the electric charge on their surface ('patch attraction'). On the other hand, by changing the polyelectrolyte/particle charge ratio, ξ s , the interaction between like-charged polyelectrolyte-decorated (pd) particles, at short separations, evolves from purely repulsive to strongly attractive. Hence, the effective interaction between the complexes is characterized by a potential barrier, whose height depends on the net charge and on the non-uniformity of their surface charge distribution.2

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Microscopics of Complexation between Long DNA Molecules and Positively Charged Colloids

Cited by 91 publications

References 18 publications

Effect of Temperature on the Reentrant Condensation in Polyelectrolyte−Liposome Complexation

Effect of Temperature on the Reentrant Condensation in Polyelectrolyte−Liposome Complexation

Phase diagram of aggregation of oppositely charged colloids in salty water

Interaction between like-charged polyelectrolyte-colloid complexes in electrolyte solutions: A Monte Carlo simulation study in the Debye–Hückel approximation

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