Abstract
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 language | English |
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Pages (from-to) | 213-220 |
Number of pages | 8 |
Journal | Journal of Controlled Release |
Volume | 51 |
Issue number | 2-3 |
DOIs | |
Publication status | Published - 1998 Feb 12 |
Keywords
- Cell transfection
- Charge complex
- Chitosan self-aggregate
- Hydrophobic modification
- Plasmid DNA
ASJC Scopus subject areas
- Pharmaceutical Science