1
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Kłos JS, Paturej J. Binding mechanisms in dendrimer-surfactant complexes. Phys Rev E 2022; 105:034501. [PMID: 35428143 DOI: 10.1103/physreve.105.034501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
Molecular dynamics simulations were employed to investigate the impact of interactions between dendritic polyeclectrolytes and amphiphilic surfactants on the supramolecular complex formation. We recognize two crucial parameters that govern association of surfactants within dendrimers: surfactant hydrophobicity, ε^{*}, and dendrimer generation, G. We find that depending on the values of ε^{*} and G encapsulation of surfactants by dendrimers is either noncooperative or cooperative. The noncooperative binding is characterized by absorption of surfactants as unimers, whereas in cooperative binding absorption of unimers is followed by aggregate formation through hydrophobic attractions between the surfactant tails. Our results provide guidelines for controlled encapsulation of guest molecules in dendrimer-based guest-host complexes.
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Affiliation(s)
- J S Kłos
- Faculty of Physics, A. Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
- Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany
| | - J Paturej
- Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany
- Institute of Physics, University of Silesia, 75 Pułku Piechoty 1, 41-500 Chorzów, Poland
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2
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Markelov DA, Semisalova AS, Mazo MA. Formation of a Hollow Core in Dendrimers in Solvents. MACROMOL CHEM PHYS 2021. [DOI: 10.1002/macp.202100085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Denis A. Markelov
- Saint Petersburg State University Universitetskaya nab. 7/9 St. Petersburg 199034 Russia
| | - Anna S. Semisalova
- Faculty of Physics and CENIDE University of Duisburg‐Essen Lotharstr. 1 Duisburg 47057 Germany
| | - Mikhail A. Mazo
- Semenov Institute of Chemical Physics Russian Academy of Sciences Kosygina 4 Moscow 119991 Russia
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3
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Spatial segregation of mixed-sized counterions in dendritic polyelectrolytes. Sci Rep 2021; 11:8108. [PMID: 33854111 PMCID: PMC8046808 DOI: 10.1038/s41598-021-87448-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/30/2021] [Indexed: 11/08/2022] Open
Abstract
Langevin dynamics simulations are utilized to study the structure of a dendritic polyelectrolyte embedded in two component mixtures comprised of conventional (small) and bulky counterions. We vary two parameters that trigger conformational properties of the dendrimer: the reduced Bjerrum length, [Formula: see text], which controls the strength of electrostatic interactions and the number fraction of the bulky counterions, [Formula: see text], which impacts on their steric repulsion. We find that the interplay between the electrostatic and the counterion excluded volume interactions affects the swelling behavior of the molecule. As compared to its neutral counterpart, for weak electrostatic couplings the charged dendrimer exists in swollen conformations whose size remains unaffected by [Formula: see text]. For intermediate couplings, the absorption of counterions into the pervaded volume of the dendrimer starts to influence its conformation. Here, the swelling factor exhibits a maximum which can be shifted by increasing [Formula: see text]. For strong electrostatic couplings the dendrimer deswells correspondingly to [Formula: see text]. In this regime a spatial separation of the counterions into core-shell microstructures is observed. The core of the dendrimer cage is preferentially occupied by the conventional ions, whereas its periphery contains the bulky counterions.
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4
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Affiliation(s)
- J. S. Kłos
- Faculty of Physics, A. Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
- Leibniz Institute of Polymer Research Dresden e.V., 01069 Dresden, Germany
| | - J. Paturej
- Institute of Physics, University of Silesia, 75 Pułku Piechoty 1, 41-500 Chorzów, Poland and
- Leibniz Institute of Polymer Research Dresden e.V., 01069 Dresden, Germany
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5
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Kłos JS. The Poisson–Boltzmann–Flory Approach to Charged Dendrimers: Effect of Generation and Spacer Length. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b00446] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. S. Kłos
- Faculty of Physics, A. Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland
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6
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Freire JJ, Rubio AM. Binary Intermolecular Potential and Scattering Curves of PAMAM-EDA Dendrimers. MACROMOL THEOR SIMUL 2018. [DOI: 10.1002/mats.201800004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Juan J. Freire
- Departamento de Ciencias y Técnicas Fisicoquímicas; Facultad de Ciencias; Universidad Nacional de Educación a Distancia (UNED); Paseo Senda del Rey 9 28040 Madrid Spain
| | - Ana M. Rubio
- Departamento de Química Física; Facultad de Ciencias Químicas; Universidad Complutense; 28040 Madrid Spain
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7
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Kłos JS. Dendritic polyelectrolytes revisited through the Poisson-Boltzmann-Flory theory and the Debye-Hückel approximation. Phys Chem Chem Phys 2018; 20:2693-2703. [PMID: 29319706 DOI: 10.1039/c7cp07138h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The properties of a dendritic polyelectrolyte in equilibrium with a reservoir of monovalent salts are investigated using the cell model and the Poisson-Boltzmann-Flory theory. Within this approach we use the Debye-Hückel approximation to solve the Poisson-Boltzmann equation and minimize the semi-grand potential of the system with respect to the size of the molecule which enables us to inspect its conformations as well as the electric field, the ionic density profile, the overall charge density, the effective charge of the dendrimer and the osmotic pressure based on their response to the salt concentration and the dendrimer charge. The model predicts pronounced trapping of salt ions, a local charge neutrality and a zero electric field in the volume of the molecule as well as oscillations of the density profiles and the electric field in the vicinity of the dendrimer-bulk interface. As a result of ion trapping and screening of Coulomb interactions monovalent salts are found to have a minor effect on the size of the dendrimer. Specifically, the dendrimer exists in slightly swollen states as compared to the neutral molecule which indicates that the conformational properties of the polyelectrolyte depend weakly on monovalent salts. These observations harmonise with the equilibrium behavior of the dendrimer pressure, the internal pressure and the bulk pressure, respectively.
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Affiliation(s)
- J S Kłos
- Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland.
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8
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Kłos JS, Milewski J. Dendritic polyelectrolytes as seen by the Poisson–Boltzmann–Flory theory. Phys Chem Chem Phys 2018; 20:17818-17828. [DOI: 10.1039/c8cp02440e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The conformational and electrostatic properties of dendritic polyelectrolytes accompanied by counterions are investigated using the Poisson–Boltzmann–Flory theory.
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Affiliation(s)
- J. S. Kłos
- Faculty of Physics
- A. Mickiewicz University
- 61-614 Poznań
- Poland
- Leibniz Institute of Polymer Research Dresden e.V
| | - J. Milewski
- Institute of Mathematics
- Faculty of Electrical Engineering
- Poznań University of Technology
- 60-963 Poznań
- Poland
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9
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Yu C, Ma L, Li K, Li S, Liu Y, Liu L, Zhou Y, Yan D. Computer Simulation Studies on the pH-Responsive Self-Assembly of Amphiphilic Carboxy-Terminated Polyester Dendrimers in Aqueous Solution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:388-399. [PMID: 28001081 DOI: 10.1021/acs.langmuir.6b03480] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This paper investigates the pH-responsive self-assembly of an amphiphilic carboxyl-terminated polyester dendrimer, H20-COOH, in aqueous solution using the dissipative particle dynamics method. The electrostatic interactions were described by introducing the explicit interaction between the smeared charges on ionized polymer beads and the counterions. The results show that the self-assemblies could change from unimolecular micelles, microphase-separated small micelles, wormlike micelles, sheetlike micelles, and small vesicles to large vesicles with the decrease in the degree of ionization (α) of carboxylic acid groups. In addition, the detailed self-assembly mechanisms and the molecular packing models have also been disclosed for each self-assembly stages. Interestingly, the wormlike micelles are found to change from linear to branched when α decreases from 0.182 to 0.109. The current work might serve as a comprehensive understanding on the effect of carboxylic acid groups on the self-assembly behaviors of dendritic polymers.
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Affiliation(s)
- Chunyang Yu
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, China
| | - Li Ma
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, China
| | - Ke Li
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, China
| | - Shanlong Li
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, China
| | - Yannan Liu
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, China
| | - Lifen Liu
- Center for Membrane and Water Science and Technology, Ocean College, Zhejiang University of Technology , Hangzhou 310014, China
| | - Yongfeng Zhou
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, China
| | - Deyue Yan
- School of Chemistry & Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, China
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10
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Merlitz H, Li C, Wu C, Sommer JU. Polyelectrolyte brushes in external fields: molecular dynamics simulations and mean-field theory. SOFT MATTER 2015; 11:5688-5696. [PMID: 26096075 DOI: 10.1039/c5sm01275a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A mean-field model is developed to predict the layer-thickness of sparse and salt-free polyelectrolyte brushes, exposed to an external electric field, which attracts the polyelectrolytes to the substrate. In molecular dynamics simulations, it is shown that a fraction of polymers collapses entirely to screen the charge of the substrate. The remaining brushes are then treated as field-free brushes at reduced grafting density. The mean-field model may thus be applied to field-free brushes, both in their osmotic and their weak charge regimes. It yields simple, closed equations for the brush height and for the partition of counterions in- and outside the brushes, and accurately reproduces simulation data of the collapse of the brushes during the crossover between both charge regimes.
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Affiliation(s)
- Holger Merlitz
- Department of Physics and ITPA, Xiamen University, Xiamen 361005, P. R. China.
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11
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Freire JJ, Rubio AM, McBride C. Coarse-Grained and Atomistic Simulations for theG = 4 PAMAM-EDA Dendrimer. MACROMOL THEOR SIMUL 2015. [DOI: 10.1002/mats.201500028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Juan J. Freire
- Departamento de Ciencias y Técnicas Fisicoquímicas, Facultad de Ciencias; Universidad Nacional de Educación a Distancia; Paseo Senda del Rey 9 28040 Madrid Spain
| | - Ana M. Rubio
- Departamento de Química Física, Facultad de Ciencias Químicas; Universidad Complutense; 28040 Madrid Spain
| | - Carl McBride
- Departamento de Ciencias y Técnicas Fisicoquímicas, Facultad de Ciencias; Universidad Nacional de Educación a Distancia; Paseo Senda del Rey 9 28040 Madrid Spain
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12
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Kłos JS, Sommer JU. Simulations of a Grafted Dendritic Polyelectrolyte in Electric Fields. Macromolecules 2015. [DOI: 10.1021/ma502301a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. S. Kłos
- Leibniz Institute
of Polymer Research Dresden e.V., 01069 Dresden, Germany
- Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland
| | - J.-U. Sommer
- Leibniz Institute
of Polymer Research Dresden e.V., 01069 Dresden, Germany
- Institute for Theoretical
Physics, Technische Universität Dresden, 01069 Dresden, Germany
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13
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Sommer JU, Kłos JS, Mironova ON. Adsorption of branched and dendritic polymers onto flat surfaces: a Monte Carlo study. J Chem Phys 2014; 139:244903. [PMID: 24387392 DOI: 10.1063/1.4849176] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Using Monte Carlo simulations based on the bond fluctuation model we study the adsorption of starburst dendrimers with flexible spacers onto a flat surface. The calculations are performed for various generation number G and spacer length S in a wide range of the reduced temperature τ as the measure of the interaction strength between the monomers and the surface. Our simulations indicate a two-step adsorption scenario. Below the critical point of adsorption, τc, a weakly adsorbed state of the dendrimer is found. Here, the dendrimer retains its shape but sticks to the surface by adsorbed spacers. By lowering the temperature below a spacer-length dependent value, τ*(S) < τc, a step-like transition into a strongly adsorbed state takes place. In the flatly adsorbed state the shape of the dendrimer is well described by a mean field model of a dendrimer in two dimensions. We also performed simulations of star-polymers which display a simple crossover-behavior in full analogy to linear chains. By analyzing the order parameter of the adsorption transition, we determine the critical point of adsorption of the dendrimers which is located close to the critical point of adsorption for star-polymers. While the order parameter for the adsorbed spacers displays a critical crossover scaling, the overall order parameter, which combines both critical and discontinuous transition effects, does not display simple scaling. The step-like transition from the weak into the strong adsorbed regime is confirmed by analyzing the shape-anisotropy of the dendrimers. We present a mean-field model based on the concept of spacer adsorption which predicts a discontinuous transition of dendrimers due to an excluded volume barrier. The latter results from an increased density of the dendrimer in the flatly adsorbed state which has to be overcome before this state is thermodynamically stable.
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Affiliation(s)
- J-U Sommer
- Leibniz Institute of Polymer Research Dresden e. V., 01069 Dresden, Germany
| | - J S Kłos
- Leibniz Institute of Polymer Research Dresden e. V., 01069 Dresden, Germany
| | - O N Mironova
- Leibniz Institute of Polymer Research Dresden e. V., 01069 Dresden, Germany
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14
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Jurjiu A, Dockhorn R, Mironova O, Sommer JU. Two universality classes for random hyperbranched polymers. SOFT MATTER 2014; 10:4935-4946. [PMID: 24882064 DOI: 10.1039/c4sm00711e] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We grow AB2 random hyperbranched polymer structures in different ways and using different simulation methods. In particular we use a method of ad hoc construction of the connectivity matrix and the bond fluctuation model on a 3D lattice. We show that hyperbranched polymers split into two universality classes depending on the growth process. For a "slow growth" (SG) process where monomers are added sequentially to an existing molecule which strictly avoids cluster-cluster aggregation the resulting structures share all characteristic features with regular dendrimers. For a "quick growth" (QG) process which allows for cluster-cluster aggregation we obtain structures which can be identified as random fractals. Without excluded volume interactions the SG model displays a logarithmic growth of the radius of gyration with respect to the degree of polymerization while the QG model displays a power law behavior with an exponent of 1/4. By analyzing the spectral properties of the connectivity matrix we confirm the behavior of dendritic structures for the SG model and the corresponding fractal properties in the QG case. A mean field model is developed which explains the extension of the hyperbranched polymers in an athermal solvent for both cases. While the radius of gyration of the QG model shows a power-law behavior with the exponent value close to 4/5, the corresponding result for the SG model is a mixed logarithmic-power-law behavior. These different behaviors are confirmed by simulations using the bond fluctuation model. Our studies indicate that random sequential growth according to our SG model can be an alternative to the synthesis of perfect dendrimers.
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Affiliation(s)
- A Jurjiu
- Leibniz Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, D-01069, Dresden, Germany.
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15
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Das AK, Hsiao PY. Charged dendrimers in trivalent salt solutions under the action of DC electric fields. J Phys Chem B 2014; 118:6265-76. [PMID: 24837658 DOI: 10.1021/jp4116589] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The structural properties and electrophoretic mobility of charged dendrimers in 3:1 electrolyte solutions subjected to direct current electric fields are studied using molecular dynamics simulations. The simulated dendrimer size is studied in zero fields and found to scale as R(g) ∼ N(0.29). The dendrimers exhibit shape distortions when the applied electric field is larger than some critical value, which scales with the number of dendrimer monomers as E(z,crit) ∼ N(0.39(6)). Families of curves, such as the curves of the square of radius of gyration, the asphericity, the degree of prolateness, and the electrophoretic mobility of dendrimers, are shown to collapse to single, master curves in electric fields through appropriate scaling. This reflects the fractal characteristics of these systems. The density profile of the surface monomers and salt cations reveals two pronounced combination effects between the polarization of dendrimer complexes and stripping-off of the condensed salt cations from the dendrimer surface.
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Affiliation(s)
- Ashok K Das
- Department of Engineering and System Science, National Tsing Hua University , Hsinchu, 30013, Taiwan, R. O. C
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16
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Wawrzyńska E, Eisenhaber S, Parzuchowski P, Sikorski A, Zifferer G. Monte Carlo Simulation Studies of the Size and Shape of Regular Three Generation Dendrimers. MACROMOL THEOR SIMUL 2014. [DOI: 10.1002/mats.201300159] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Edyta Wawrzyńska
- Department of Physical Chemistry; University of Vienna; Währinger Str. 42 A-1090 Vienna Austria
- Department of Chemistry; Warsaw University of Technology; Noakowskiego 3 00-664 Warsaw Poland
- Department of Chemistry; University of Warsaw; Pasteura 1 02-093 Warsaw Poland
| | - Stephan Eisenhaber
- Department of Physical Chemistry; University of Vienna; Währinger Str. 42 A-1090 Vienna Austria
| | - Paweł Parzuchowski
- Department of Chemistry; Warsaw University of Technology; Noakowskiego 3 00-664 Warsaw Poland
| | - Andrzej Sikorski
- Department of Chemistry; University of Warsaw; Pasteura 1 02-093 Warsaw Poland
| | - Gerhard Zifferer
- Department of Physical Chemistry; University of Vienna; Währinger Str. 42 A-1090 Vienna Austria
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17
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Drug-dendrimer supramolecular complexation studied from molecular dynamics simulations and NMR spectroscopy. Struct Chem 2014. [DOI: 10.1007/s11224-014-0424-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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18
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Barra PA, Barraza L, Jiménez VA, Gavín JA, Alderete JB. Complexation of Mefenamic Acid by Low-Generation PAMAM Dendrimers: Insight from NMR Spectroscopy Studies and Molecular Dynamics Simulations. MACROMOL CHEM PHYS 2014. [DOI: 10.1002/macp.201300398] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Pabla A. Barra
- Departamento de Química Orgánica; Facultad de Ciencias Químicas; Universidad de Concepcion; Casilla 160-C Concepcion Chile
| | - Luis Barraza
- Departamento de Química Orgánica; Facultad de Ciencias Químicas; Universidad de Concepcion; Casilla 160-C Concepcion Chile
| | - Verónica A. Jiménez
- Departamento de Química Orgánica; Facultad de Ciencias Químicas; Universidad de Concepcion; Casilla 160-C Concepcion Chile
| | - José A. Gavín
- Instituto Universitario de Bioorgánica, “A. González”; Universidad de la Laguna; Avda. Astrofísico F. Sánchez 2 La Laguna Tenerife Spain
| | - Joel B. Alderete
- Departamento de Química Orgánica; Facultad de Ciencias Químicas; Universidad de Concepcion; Casilla 160-C Concepcion Chile
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19
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Welch PM. The escape of a charged dendrimer from an oppositely charged planar surface. J Chem Phys 2013; 139:164906. [PMID: 24182078 DOI: 10.1063/1.4826575] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Many of the envisioned applications of dendrimers revolve around placing these molecules at and removing them from charged interfaces. Herein, we provide a prescription for the conditions needed to release a charged dendrimer from an oppositely charged flat substrate. Identifying an effective segment step length that reflects the intramolecular repulsions due to excluded volume and electrostatics, as well as the dendrimer's branching, provides the essential concept leading to an analytical prediction for the boundary between captured and free molecules. We find that this effective step length obeys trends similar to those predicted for linear chains, but is modified by the dendrimer's connectivity. Moreover, the boundary predicted for the capture of linear chains holds for dendrimers once this effective step length is employed. Monte Carlo computer simulations of coarse-grained model dendrimers escaping from charged surfaces validate these findings. The simulations consider generations 2 through 6 with a range of lengths between the branch points, as well as a range of solution ionic strengths and surface charge densities.
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Affiliation(s)
- P M Welch
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545-0001, USA
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20
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Kłos JS, Sommer JU. Coarse grained simulations of neutral and charged dendrimers. POLYMER SCIENCE SERIES C 2013. [DOI: 10.1134/s1811238213070023] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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21
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Tian WD, Ma YQ. Theoretical and computational studies of dendrimers as delivery vectors. Chem Soc Rev 2013; 42:705-27. [PMID: 23114420 DOI: 10.1039/c2cs35306g] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
It is a great challenge for nanomedicine to develop novel dendrimers with maximum therapeutic potential and minimum side-effects for drug and gene delivery. As delivery vectors, dendrimers must overcome lots of barriers before delivering the bio-agents to the target in the cell. Extensive experimental investigations have been carried out to elucidate the physical and chemical properties of dendrimers and explore their behaviors when interacting with biomolecules, such as gene materials, proteins, and lipid membranes. As a supplement of the experimental techniques, it has been proved that computer simulations could facilitate the progress in understanding the delivery process of bioactive molecules. The structures of dendrimers in dilute solutions have been intensively investigated by monomer-resolved simulations, coarse-grained simulations, and atom-resolved simulations. Atomistic simulations have manifested that the hydrophobic interactions, hydrogen-bond interactions, and electrostatic attraction play critical roles in the formation of dendrimer-drug complexes. Multiscale simulations and statistical field theories have uncovered some physical mechanisms involved in the dendrimer-based gene delivery systems. This review will focus on the current status and perspective of theoretical and computational contributions in this field in recent years. (275 references).
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Affiliation(s)
- Wen-de Tian
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China
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22
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Kłos JS, Sommer JU. Simulations of Neutral and Charged Dendrimers in Solvents of Varying Quality. Macromolecules 2013. [DOI: 10.1021/ma4001989] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- J. S. Kłos
- Leibniz Institute of Polymer Research Dresden e.V., 01069 Dresden, Germany
- Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań,
Poland
| | - J.-U. Sommer
- Leibniz Institute of Polymer Research Dresden e.V., 01069 Dresden, Germany
- Institute for Theoretical Physics, Technische Universität Dresden, 01069 Dresden,
Germany
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23
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Wu B, Liu Y, Li X, Mamontov E, Kolesnikov AI, Diallo SO, Do C, Porcar L, Hong K, Smith SC, Liu L, Smith GS, Egami T, Chen WR. Charge-Dependent Dynamics of a Polyelectrolyte Dendrimer and Its Correlation with Invasive Water. J Am Chem Soc 2013; 135:5111-7. [DOI: 10.1021/ja3125959] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bin Wu
- Department of Mechanical, Aerospace & Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Yun Liu
- The NIST Center for Neutron
Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6100, United States
- Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716, United
States
| | | | | | | | | | | | - Lionel Porcar
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble CEDEX 9, France
| | | | | | - Li Liu
- Department of Mechanical, Aerospace & Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | | | - Takeshi Egami
- Department of Materials Science
and Engineering and Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1508,
United States
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Kłos JS, Sommer JU. Simulation of Complexes between a Charged Dendrimer and a Linear Polyelectrolyte with Finite Rigidity. MACROMOL THEOR SIMUL 2012. [DOI: 10.1002/mats.201100120] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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25
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Wu B, Kerkeni B, Egami T, Do C, Liu Y, Wang Y, Porcar L, Hong K, Smith SC, Liu EL, Smith GS, Chen WR. Structured water in polyelectrolyte dendrimers: Understanding small angle neutron scattering results through atomistic simulation. J Chem Phys 2012; 136:144901. [DOI: 10.1063/1.3697479] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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26
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Poly(amidoamine)-based Dendrimer/siRNA Complexation Studied by Computer Simulations: Effects of pH and Generation on Dendrimer Structure and siRNA Binding. Macromol Biosci 2011; 12:225-40. [DOI: 10.1002/mabi.201100276] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Indexed: 12/13/2022]
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27
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Wu B, Li X, Do C, Kim TH, Shew CY, Liu Y, Yang J, Hong K, Porcar L, Chen CY, Liu EL, Smith GS, Herwig KW, Chen WR. Spatial distribution of intra-molecular water and polymeric components in polyelectrolyte dendrimers revealed by small angle scattering investigations. J Chem Phys 2011; 135:144903. [DOI: 10.1063/1.3651364] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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28
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Kłos JS, Sommer JU. Monte Carlo simulations of charged dendrimer-linear polyelectrolyte complexes and explicit counterions. J Chem Phys 2011; 134:204902. [PMID: 21639472 DOI: 10.1063/1.3592558] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We study complexes composed of one dendrimer of generation G = 4 (G4 dendrimer) with N(t) = 32 charged terminal groups and an oppositely charged linear polyelectrolyte accompanied by neutralizing counterions in an athermal solvent using Monte Carlo simulations based on the bond fluctuation model. In our study both the full Coulomb potential and the excluded volume interactions are taken into account explicitly with the reduced temperature τ and the chain length N(ch) as the main simulation parameters. Our calculations indicate that there exist three temperature ranges that determine the behavior of such complexes. At τ(complex) stable charged dendrimer-linear polyelectrolyte complexes are formed first, which are subsequently accompanied by selective counterion localization within the complex interior at τ(loc) ≤ τ(complex), and counterion condensation as temperature is further decreased below τ(cond) < τ(loc). In particular, we observe that condensation takes place exclusively on the excess charges in the complex and thus no condensation is observed at the compensation point (N(ch) = N(t)), irrespective of τ. For N(ch) ≠ N(t) the complex is overally charged. Furthermore, we discuss the size and structure of the dendrimer and the linear polyelectrolyte within the complex, as well as spatial distributions of monomers and counterions. Conformations of the chain in the bound state are analysed in terms of loops, trains, and tails.
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Affiliation(s)
- J S Kłos
- Leibniz Institute of Polymer Research Dresden e.V., 01069 Dresden, Germany.
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29
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Dolgushev M, Berezovska G, Blumen A. Branched Semiflexible Polymers: Theoretical and Simulation Aspects. MACROMOL THEOR SIMUL 2011. [DOI: 10.1002/mats.201100049] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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30
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Chen L, Merlitz H, He SZ, Wu CX, Sommer JU. Polyelectrolyte Brushes: Debye Approximation and Mean-Field Theory. Macromolecules 2011. [DOI: 10.1021/ma1024413] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Long Chen
- Department of Physics and ITPA, Xiamen University, Xiamen 361005, P. R. China
| | - Holger Merlitz
- Department of Physics and ITPA, Xiamen University, Xiamen 361005, P. R. China
- Leibniz-Institut für Polymerforschung Dresden, 01069 Dresden, Germany
| | - Su-zhen He
- Department of Physics and ITPA, Xiamen University, Xiamen 361005, P. R. China
- Department of Electronic Engineering, Putian University, Putian 351100, P. R. China
| | - Chen-Xu Wu
- Department of Physics and ITPA, Xiamen University, Xiamen 361005, P. R. China
| | - Jens-Uwe Sommer
- Leibniz-Institut für Polymerforschung Dresden, 01069 Dresden, Germany
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