DNA-lipid systems. A physical chemistry study
Braz. j. med. biol. res
;
35(5): 509-522, May 2002. ilus, graf
Article
in English
| LILACS
| ID: lil-308279
ABSTRACT
It is well known that the interaction of polyelectrolytes with oppositely charged surfactants leads to an associative phase separation; however, the phase behavior of DNA and oppositely charged surfactants is more strongly associative than observed in other systems. A precipitate is formed with very low amounts of surfactant and DNA. DNA compaction is a general phenomenon in the presence of multivalent ions and positively charged surfaces; because of the high charge density there are strong attractive ion correlation effects. Techniques like phase diagram determinations, fluorescence microscopy, and ellipsometry were used to study these systems. The interaction between DNA and catanionic mixtures (i.e., mixtures of cationic and anionic surfactants) was also investigated. We observed that DNA compacts and adsorbs onto the surface of positively charged vesicles, and that the addition of an anionic surfactant can release DNA back into solution from a compact globular complex between DNA and the cationic surfactant. Finally, DNA interactions with polycations, chitosans with different chain lengths, were studied by fluorescence microscopy, in vivo transfection assays and cryogenic transmission electron microscopy. The general conclusion is that a chitosan effective in promoting compaction is also efficient in transfection
Full text:
Available
Index:
LILACS (Americas)
Main subject:
DNA
/
Lipids
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2002
Type:
Article
/
Congress and conference
/
Project document
Affiliation country:
Portugal
/
Sweden
Institution/Affiliation country:
Lund University/SE
/
Universidade de Coimbra/PT
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