Preparation of chitosan self-aggregates as a gene delivery system

K. Y. Lee, I. C. Kwon, Y. H. Kim, W. H. Jo, S. Y. Jeong

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413 Citations (Scopus)


Hydrophobically modified chitosan containing 5.1 deoxycholic acid groups per 100 anhydroglucose units was synthesized by an EDC-mediated coupling reaction. Formation and characteristics of self-aggregates of hydrophobically modified chitosan were studied by fluorescence spectroscopy and dynamic light scattering method. The critical aggregation concentration (cac) of the self- aggregate was determined by measuring the fluorescence intensity of pyrene as a fluorescent probe. The cac value in PBS solution (pH 7.2) was 1.7 x 10-2 mg/ml. Mean diameter of self-aggregates in PBS solution (pH 7.2) was 162 ± 18 nm with an unimodal size distribution. Charge complex formation between self-aggregates and plasmid DNA was confirmed by electrophoresis on an agarose gel. Migration of DNA on an agarose gel was completely retarded above a charge ratio (+/-) of 4/1 at pH 7.2. The free DNA dissociated from the complexes was observed by electrophoresis above pH 8.0 at a fixed charge ratio of 4/1. An efficient transfection of COS-1 cells was achieved by self- aggregates/DNA complexes.

Original languageEnglish
Pages (from-to)213-220
Number of pages8
JournalJournal of Controlled Release
Issue number2-3
Publication statusPublished - 1998 Feb 12


  • Cell transfection
  • Charge complex
  • Chitosan self-aggregate
  • Hydrophobic modification
  • Plasmid DNA

ASJC Scopus subject areas

  • Pharmaceutical Science


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