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Interactions between DNA and Poly(amido amine) Dendrimers on Silica Surfaces.

Ainalem, Marie-Louise LU ; Campbell, Richard LU and Nylander, Tommy LU (2010) In Langmuir 26(11). p.8625-8635
Abstract
This study increases the understanding at a molecular level of the interactions between DNA and poly(amido amine) (PAMAM) dendrimers on solid surfaces, which is a subject of potential interest in applications such as gene therapy. We have used in situ null ellipsometry and neutron reflectometry to study the structure of multilayer arrangements formed by PAMAM dendrimers of generation 2 (G2), 4 (G4), and 6 (G6) and DNA on silica surfaces. Specifically, we adsorbed cationic dendrimer layers, then we condensed DNA to form dendrimer-DNA bilayers, and last we exposed further dendrimer molecules to the interface to encapsulate DNA in dendrimer-DNA-dendrimer trilayers. The dendrimer monolayers formed initially result in the deformation of the... (More)
This study increases the understanding at a molecular level of the interactions between DNA and poly(amido amine) (PAMAM) dendrimers on solid surfaces, which is a subject of potential interest in applications such as gene therapy. We have used in situ null ellipsometry and neutron reflectometry to study the structure of multilayer arrangements formed by PAMAM dendrimers of generation 2 (G2), 4 (G4), and 6 (G6) and DNA on silica surfaces. Specifically, we adsorbed cationic dendrimer layers, then we condensed DNA to form dendrimer-DNA bilayers, and last we exposed further dendrimer molecules to the interface to encapsulate DNA in dendrimer-DNA-dendrimer trilayers. The dendrimer monolayers formed initially result in the deformation of the cationic adsorbates as a result of their strong electrostatic attraction to the hydrophilic silica surface. The highest surface excess and most pronounced deformation occurs for the G6 molecules due to their relatively large size and high surface charge density. G6-functionalized surfaces give rise to the highest surface excess of DNA during the bilayer formation process. This result is explained in terms of the high number of charged binding sites in the G6 monolayer and the low electrostatic repulsion between DNA and exposed patches of silica surface due to the relatively thick G6 monolayer. The binding strengths of the silica-dendrimer and dendrimer-DNA interactions are demonstrated by the high stability of the interfacial bilayers during rinsing. For the formation of trilayers of dendrimers, DNA, and dendrimers, G2 adsorbs as a smooth layer while G4 and G6 induce the formation of less well-defined structures due to more complex DNA layer morphologies. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Langmuir
volume
26
issue
11
pages
8625 - 8635
publisher
The American Chemical Society
external identifiers
  • wos:000277928100129
  • pmid:20429604
  • scopus:77954561366
ISSN
0743-7463
DOI
10.1021/la9047177
language
English
LU publication?
yes
id
939807a9-eb80-4fb9-8a0e-75bd4251cc0c (old id 1610732)
date added to LUP
2010-06-09 12:26:16
date last changed
2018-05-29 10:15:19
@article{939807a9-eb80-4fb9-8a0e-75bd4251cc0c,
  abstract     = {This study increases the understanding at a molecular level of the interactions between DNA and poly(amido amine) (PAMAM) dendrimers on solid surfaces, which is a subject of potential interest in applications such as gene therapy. We have used in situ null ellipsometry and neutron reflectometry to study the structure of multilayer arrangements formed by PAMAM dendrimers of generation 2 (G2), 4 (G4), and 6 (G6) and DNA on silica surfaces. Specifically, we adsorbed cationic dendrimer layers, then we condensed DNA to form dendrimer-DNA bilayers, and last we exposed further dendrimer molecules to the interface to encapsulate DNA in dendrimer-DNA-dendrimer trilayers. The dendrimer monolayers formed initially result in the deformation of the cationic adsorbates as a result of their strong electrostatic attraction to the hydrophilic silica surface. The highest surface excess and most pronounced deformation occurs for the G6 molecules due to their relatively large size and high surface charge density. G6-functionalized surfaces give rise to the highest surface excess of DNA during the bilayer formation process. This result is explained in terms of the high number of charged binding sites in the G6 monolayer and the low electrostatic repulsion between DNA and exposed patches of silica surface due to the relatively thick G6 monolayer. The binding strengths of the silica-dendrimer and dendrimer-DNA interactions are demonstrated by the high stability of the interfacial bilayers during rinsing. For the formation of trilayers of dendrimers, DNA, and dendrimers, G2 adsorbs as a smooth layer while G4 and G6 induce the formation of less well-defined structures due to more complex DNA layer morphologies.},
  author       = {Ainalem, Marie-Louise and Campbell, Richard and Nylander, Tommy},
  issn         = {0743-7463},
  language     = {eng},
  number       = {11},
  pages        = {8625--8635},
  publisher    = {The American Chemical Society},
  series       = {Langmuir},
  title        = {Interactions between DNA and Poly(amido amine) Dendrimers on Silica Surfaces.},
  url          = {http://dx.doi.org/10.1021/la9047177},
  volume       = {26},
  year         = {2010},
}