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Relationship between the physical shape and the efficiency of oligomeric chitosan as a gene delivery system in vitro and in vivo

Köping-Hoggard, M; Mel'nikova, Y S; Vårum, K M; Lindman, Björn LU and Artursson, P (2003) In Journal of Gene Medicine 5(2). p.130-141
Abstract
Background Chitosans of high molecular weights have emerged as efficient. nonviral gene delivery systems, but the properties and efficiency of well-defined low molecular weight chitosans ((.) 5 kDa) have not been studied. We therefore characterized DNA complexes Of Such low molecular weight chitosans and related their physical shape and stability to their efficiency as gene delivery systems in vitro and in vivo.Methods Individual complexes between six different chitosan oligomers (6-, 8-, 10-, 12-, 14- and 24-mers) and fluorescence-labeled T4 DNA were visualized and classified into six physical shapes using video-enhanced fluorescence microscopy. The effects of chitosan chain length, charge ratio (+/-) and solvent properties (pH and ionic... (More)
Background Chitosans of high molecular weights have emerged as efficient. nonviral gene delivery systems, but the properties and efficiency of well-defined low molecular weight chitosans ((.) 5 kDa) have not been studied. We therefore characterized DNA complexes Of Such low molecular weight chitosans and related their physical shape and stability to their efficiency as gene delivery systems in vitro and in vivo.Methods Individual complexes between six different chitosan oligomers (6-, 8-, 10-, 12-, 14- and 24-mers) and fluorescence-labeled T4 DNA were visualized and classified into six physical shapes using video-enhanced fluorescence microscopy. The effects of chitosan chain length, charge ratio (+/-) and solvent properties (pH and ionic strength) on the stability and structure of the complexes were studied. Gene expression in vitro and in vivo were studied using a luciferas

reporter gene.Results Free DNA appeared as extended coils. Chitosan complexes had, a variety of physical shapes depending on the experimental conditions. in general, the fraction of complexes that had nonaggregated, globular structures increased with increasing chain length of the chitosan oligomer, increasing charge ratio and reduction of pH (from 6.5 to 3.5). A further increase in charge ratio for globular complexes or a further reduction in pH (to 2.5) increased the fraction of aggregates, indicating a window where pharmaceutically desirable globules are obtained. Gene transfection efficiencies in vitro and in vivo were related to the physical shape and stability of the complexes. Only the 24-mer formed stable complexes that gave a high level of gene expression comparable to that of high molecular weight ultrapure chitosan (UPC) in vitro and in vivo.Conclusions Chitosan oligomers form complexes with DNA in a structure-dependent manner. We conclude that the 24-mer, which has more desirable physical prope

ties than UPC, is more attractive as a gene delivery system than the conventional high molecular weight chitosans. Copyright (C) 2002 John Wiley Sons, Ltd. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Gene Medicine
volume
5
issue
2
pages
130 - 141
publisher
John Wiley & Sons
external identifiers
  • wos:000181051000004
  • scopus:0242322948
ISSN
1521-2254
DOI
10.1002/jgm.327
language
English
LU publication?
yes
id
70ca9436-e66e-46b5-963e-11f3ddbf85dc (old id 122078)
date added to LUP
2007-07-11 14:51:25
date last changed
2018-01-07 05:53:55
@article{70ca9436-e66e-46b5-963e-11f3ddbf85dc,
  abstract     = {Background Chitosans of high molecular weights have emerged as efficient. nonviral gene delivery systems, but the properties and efficiency of well-defined low molecular weight chitosans ((.) 5 kDa) have not been studied. We therefore characterized DNA complexes Of Such low molecular weight chitosans and related their physical shape and stability to their efficiency as gene delivery systems in vitro and in vivo.Methods Individual complexes between six different chitosan oligomers (6-, 8-, 10-, 12-, 14- and 24-mers) and fluorescence-labeled T4 DNA were visualized and classified into six physical shapes using video-enhanced fluorescence microscopy. The effects of chitosan chain length, charge ratio (+/-) and solvent properties (pH and ionic strength) on the stability and structure of the complexes were studied. Gene expression in vitro and in vivo were studied using a luciferas<br/><br>
 reporter gene.Results Free DNA appeared as extended coils. Chitosan complexes had, a variety of physical shapes depending on the experimental conditions. in general, the fraction of complexes that had nonaggregated, globular structures increased with increasing chain length of the chitosan oligomer, increasing charge ratio and reduction of pH (from 6.5 to 3.5). A further increase in charge ratio for globular complexes or a further reduction in pH (to 2.5) increased the fraction of aggregates, indicating a window where pharmaceutically desirable globules are obtained. Gene transfection efficiencies in vitro and in vivo were related to the physical shape and stability of the complexes. Only the 24-mer formed stable complexes that gave a high level of gene expression comparable to that of high molecular weight ultrapure chitosan (UPC) in vitro and in vivo.Conclusions Chitosan oligomers form complexes with DNA in a structure-dependent manner. We conclude that the 24-mer, which has more desirable physical prope<br/><br>
ties than UPC, is more attractive as a gene delivery system than the conventional high molecular weight chitosans. Copyright (C) 2002 John Wiley Sons, Ltd.},
  author       = {Köping-Hoggard, M and Mel'nikova, Y S and Vårum, K M and Lindman, Björn and Artursson, P},
  issn         = {1521-2254},
  language     = {eng},
  number       = {2},
  pages        = {130--141},
  publisher    = {John Wiley & Sons},
  series       = {Journal of Gene Medicine},
  title        = {Relationship between the physical shape and the efficiency of oligomeric chitosan as a gene delivery system in vitro and in vivo},
  url          = {http://dx.doi.org/10.1002/jgm.327},
  volume       = {5},
  year         = {2003},
}