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DNA Compaction at Surfaces

Cárdenas, Marité LU (2004)
Abstract (Swedish)
Popular Abstract in Swedish

DNA kan ses som en negativ laddad polymer som samtidigt har grupper som vill undvika vatten och därför bildas den karakteristiska dubbelspiralen. DNA och ett ytaktiv ämne (tensid) som är positivt laddad, bildar olika komplex. Dessa komplex är mycket mer kompakta än DNA själv. I denna avhandling har vi undersökt DNA och DNA-tensid komplex på olika ytor. Vi har använt olika tekniker som ger information om bland annat hur mycket som fäster på ytan (adsorberas), tjockleken på det adsorberade lagret, krafter mellan de adsorberade lagren och adsorptionenhastigheten. DNA adsorberas på vattenavvisande ytor men adsorptionen ökar jätte mycket när man sätter till positivt laddad tensid. Samtidigt blir... (More)
Popular Abstract in Swedish

DNA kan ses som en negativ laddad polymer som samtidigt har grupper som vill undvika vatten och därför bildas den karakteristiska dubbelspiralen. DNA och ett ytaktiv ämne (tensid) som är positivt laddad, bildar olika komplex. Dessa komplex är mycket mer kompakta än DNA själv. I denna avhandling har vi undersökt DNA och DNA-tensid komplex på olika ytor. Vi har använt olika tekniker som ger information om bland annat hur mycket som fäster på ytan (adsorberas), tjockleken på det adsorberade lagret, krafter mellan de adsorberade lagren och adsorptionenhastigheten. DNA adsorberas på vattenavvisande ytor men adsorptionen ökar jätte mycket när man sätter till positivt laddad tensid. Samtidigt blir lagret mer kompakt. Med detta arbete hoppas vi bidra med kunskap i kampen mot cancer och ärftliga sjukdomar. (Less)
Abstract
The interfacial behavior of DNA and DNA-cationic surfactant has been studied. Particular attention was paid to the type of cationic surfactant and the DNA conformation (single or double stranded) as well as the DNA length. Adsorption of DNA-cationic surfactant complexes is determined by a delicate balance between the DNA-surface, cationic surfactant-surface, and cationic surfactant-DNA-solvent interactions. On negatively charged surfaces, where DNA experiences an effective electrostatic repulsion, adsorption of the DNA-cationic surfactant is favored once the charge density of both the DNA macromolecule and the surface is sufficiently decreased, due to the interaction with cationic surfactant ions. On hydrophobic surfaces, where both DNA... (More)
The interfacial behavior of DNA and DNA-cationic surfactant has been studied. Particular attention was paid to the type of cationic surfactant and the DNA conformation (single or double stranded) as well as the DNA length. Adsorption of DNA-cationic surfactant complexes is determined by a delicate balance between the DNA-surface, cationic surfactant-surface, and cationic surfactant-DNA-solvent interactions. On negatively charged surfaces, where DNA experiences an effective electrostatic repulsion, adsorption of the DNA-cationic surfactant is favored once the charge density of both the DNA macromolecule and the surface is sufficiently decreased, due to the interaction with cationic surfactant ions. On hydrophobic surfaces, where both DNA and cationic surfactant adsorb, a considerable increase in adsorbed amount and a significant layer compaction is observed for DNA-cationic surfactant complexes. The stability of the mixed adsorbed layer depends largely on the strength of the interaction between DNA and the cationic surfactant, as well as between the surface and the cationic surfactant. The interaction between DNA and small latex particles is similar to that of DNA and macroscopic hydrophobized flat surfaces. Cationic surfactant aggregates that are large and most likely non-spherical were identified within the DNA-cationic surfactant complexes far below the phase separation border. Moreover, the presence of a hydrophobized surface was found to facilitate the DNA compaction by cationic surfactant. Finally, the effect of DNA on an insoluble cationic surfactant film at the air-water interface was investigated. Addition of DNA expands the cationic lipid monolayer with the consequent disruption of condensed aggregates into a featureless liquid-expanded phase. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Professor Rädler, Joachim, Ludwig-Maximilians Universität München
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Polymer technology, Fysikalisk kemi, Physical chemistry, gränsskikt, Ytkemi, Surface and boundary layery chemistry, cationic amphiphiles, DNA, Polymerteknik, surface, biopolymers
pages
182 pages
publisher
Physical Chemistry 1, Lund University
defense location
Sal B Kemicentrum Lund
defense date
2004-12-17 13:15
ISBN
91-628-6273-1
language
English
LU publication?
yes
id
3b11c498-2381-493f-9429-a42add97a5b5 (old id 544057)
date added to LUP
2007-09-25 20:26:20
date last changed
2016-09-19 08:45:14
@phdthesis{3b11c498-2381-493f-9429-a42add97a5b5,
  abstract     = {The interfacial behavior of DNA and DNA-cationic surfactant has been studied. Particular attention was paid to the type of cationic surfactant and the DNA conformation (single or double stranded) as well as the DNA length. Adsorption of DNA-cationic surfactant complexes is determined by a delicate balance between the DNA-surface, cationic surfactant-surface, and cationic surfactant-DNA-solvent interactions. On negatively charged surfaces, where DNA experiences an effective electrostatic repulsion, adsorption of the DNA-cationic surfactant is favored once the charge density of both the DNA macromolecule and the surface is sufficiently decreased, due to the interaction with cationic surfactant ions. On hydrophobic surfaces, where both DNA and cationic surfactant adsorb, a considerable increase in adsorbed amount and a significant layer compaction is observed for DNA-cationic surfactant complexes. The stability of the mixed adsorbed layer depends largely on the strength of the interaction between DNA and the cationic surfactant, as well as between the surface and the cationic surfactant. The interaction between DNA and small latex particles is similar to that of DNA and macroscopic hydrophobized flat surfaces. Cationic surfactant aggregates that are large and most likely non-spherical were identified within the DNA-cationic surfactant complexes far below the phase separation border. Moreover, the presence of a hydrophobized surface was found to facilitate the DNA compaction by cationic surfactant. Finally, the effect of DNA on an insoluble cationic surfactant film at the air-water interface was investigated. Addition of DNA expands the cationic lipid monolayer with the consequent disruption of condensed aggregates into a featureless liquid-expanded phase.},
  author       = {Cárdenas, Marité},
  isbn         = {91-628-6273-1},
  keyword      = {Polymer technology,Fysikalisk kemi,Physical chemistry,gränsskikt,Ytkemi,Surface and boundary layery chemistry,cationic amphiphiles,DNA,Polymerteknik,surface,biopolymers},
  language     = {eng},
  pages        = {182},
  publisher    = {Physical Chemistry 1, Lund University},
  school       = {Lund University},
  title        = {DNA Compaction at Surfaces},
  year         = {2004},
}