Molecular dynamics study of charged dendrimers in salt-free solution: Effect of counterions

被引:70
作者
Gurtovenko, AA [1 ]
Lyulin, SV
Karttunen, M
Vattulainen, I
机构
[1] Russian Acad Sci, Inst Macromol Cpds, Bolshoi Prospect 31,VO,St, St Petersburg 199004, Russia
[2] Aalto Univ, Phys Lab, FIN-02015 Helsinki, Finland
[3] Aalto Univ, Helsinki Univ Technol, Helsinki Inst Phys, FIN-02015 Helsinki, Finland
[4] Aalto Univ, Biophys & Stat Mech Grp, Lab Computat Engn, FIN-02015 Helsinki, Finland
[5] Univ Western Ontario, Dept Appl Math, London, ON N6A 5B7, Canada
[6] Univ So Denmark, Dept Phys, Memphys Ctr Biomembrane Phys, DK-5230 Odense M, Denmark
[7] Tampere Univ Technol, Inst Phys, FIN-33101 Tampere, Finland
基金
芬兰科学院; 俄罗斯基础研究基金会;
关键词
D O I
10.1063/1.2166396
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Polyamidoamine dendrimers, being protonated under physiological conditions, represent a promising class of nonviral, nanosized vectors for drug and gene delivery. We performed extensive molecular dynamics simulations of a generic model dendrimer in a salt-free solution with dendrimer's terminal beads positively charged. Solvent molecules as well as counterions were explicitly included as interacting beads. We find that the size of the charged dendrimer depends nonmonotonically on the strength of electrostatic interactions demonstrating a maximum when the Bjerrum length equals the diameter of a bead. Many other structural and dynamic characteristics of charged dendrimers are also found to follow this pattern. We address such a behavior to the interplay between repulsive interactions of the charged terminal beads and their attractive interactions with oppositely charged counterions. The former favors swelling at small Bjerrum lengths and the latter promotes counterion condensation. Thus, counterions can have a dramatic effect on the structure and dynamics of charged dendrimers and, under certain conditions, cannot be treated implicitly. (c) 2006 American Institute of Physics.
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页数:8
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共 51 条
[1]   Dendrimers in solution: Insight from theory and simulation [J].
Ballauff, M ;
Likos, CN .
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 2004, 43 (23) :2998-3020
[2]   GROMACS - A MESSAGE-PASSING PARALLEL MOLECULAR-DYNAMICS IMPLEMENTATION [J].
BERENDSEN, HJC ;
VANDERSPOEL, D ;
VANDRUNEN, R .
COMPUTER PHYSICS COMMUNICATIONS, 1995, 91 (1-3) :43-56
[3]   MOLECULAR-DYNAMICS WITH COUPLING TO AN EXTERNAL BATH [J].
BERENDSEN, HJC ;
POSTMA, JPM ;
VANGUNSTEREN, WF ;
DINOLA, A ;
HAAK, JR .
JOURNAL OF CHEMICAL PHYSICS, 1984, 81 (08) :3684-3690
[4]   Regulation of in vitro gene expression using antisense oligonucleotides or antisense expression plasmids transfected using starburst PAMAM dendrimers [J].
Bielinska, A ;
KukowskaLatallo, JF ;
Johnson, J ;
Tomalia, DA ;
Baker, JR .
NUCLEIC ACIDS RESEARCH, 1996, 24 (11) :2176-2182
[5]   Dendrimers in drug research [J].
Boas, U ;
Heegaard, PMH .
CHEMICAL SOCIETY REVIEWS, 2004, 33 (01) :43-63
[6]   Effect of sodium chloride on a lipid bilayer [J].
Böckmann, RA ;
Hac, A ;
Heimburg, T ;
Grubmüller, H .
BIOPHYSICAL JOURNAL, 2003, 85 (03) :1647-1655
[7]   Rouse dynamics of a dendrimer model in the Theta condition [J].
Cai, CZ ;
Chen, ZU .
MACROMOLECULES, 1997, 30 (17) :5104-5117
[8]   Strongly charged flexible polyelectrolytes in poor solvents: Molecular dynamics simulations with explicit solvent [J].
Chang, RW ;
Yethiraj, A .
JOURNAL OF CHEMICAL PHYSICS, 2003, 118 (14) :6634-6647
[9]   Biological applications of dendrimers [J].
Cloninger, MJ .
CURRENT OPINION IN CHEMICAL BIOLOGY, 2002, 6 (06) :742-748
[10]   PARTICLE MESH EWALD - AN N.LOG(N) METHOD FOR EWALD SUMS IN LARGE SYSTEMS [J].
DARDEN, T ;
YORK, D ;
PEDERSEN, L .
JOURNAL OF CHEMICAL PHYSICS, 1993, 98 (12) :10089-10092